,,an ,,elem5t>y ,,/udy ,,( ,,*emi/ry ,,by ,,william ,mc,p,h,e,r,s,o,n1 ,,ph4,d4 ,,pr(essor ,,( ,,*emi/ry1 ,,ohio ,,/ate ,,univ]sity ,,& ,,william ,,edw>ds ,,h5d]son1 ,,ph4,d4 ,,associate ,,pr(essor ,,( ,,*emi/ry1 ,,ohio ,,/ate ,,univ]sity ,,revis$ ,,edition ,,g9n ,,company ,,bo/on 99 ,,new ,,york 99 ,,*icago 99 ,,london ,,copyright1 #aije1 #aijf1 ,,by ,,william ,,mcph]son ,,& ,,william ,e4 ,,h5d]son ,,all ,,rights ,,res]v$ ,! ,a!num ,press ,,g9n ,,company 99 ,,proprietors 99 ,,bo/on 99 ,u4,s4,a4 ,transcrib]'s note3 ,= ,text3 ,a ^w surr\nd$ by a c$illa su* z ?is signifies t ! ^w is bold$ 9 ! text4 ,a ^w surr\nd$ by und]scores l ?is signifies ! ^w is italics 9 ! text4 ,! italic & bold m>kup = s+le italiz$ lett]s 7su* z v>iables 9 equations7 & =eign abbreviations are delet$ = easi] read+4 ,= numb]s & equations3 ,p>5!ses h be5 add$ to cl>ify fractions4 ,und]scores be=e bracket$ numb]s 9 equations d5ote a subscript4 ,sup]scripts are designat$ ) a c>et & brackets1 e4g4 #aa4ac is #aa4a to ! ?ird p[]4 ,app5dix ,a & ,b h be5 mov$ to ! end ( ! book4 ,m9or typos h be5 correct$4 ,,preface ,9 (f]+ ?is book to tea*]s ( elem5t>y *emi/ry ! au?ors lay no claim to any great orig9ality4 ,x has be5 _! aim to prep>e a text-book con/ruct$ along l9es :i* h become recogniz$ z be/ suit$ to an elem5t>y treatm5t ( ! subject4 ,at ! same "t !y h made a consi/5t ef=t to make ! text cle> 9 outl9e1 simple 9 /yle & language1 cons]vatively mod]n 9 po9t ( view1 & ?or\ghly tea*able4 ,! "q z to :at %all be includ$ 9 an elem5t>y text on *emi/ry is p]haps ! mo/ p]plex+ "o :i* an au?or mu/ answ]4 ,:ile an en?usia/ic *emi/ ) a broad und]/&+ ( ! sci5ce is v apt to g beyond ! capacity ( ! elem5t>y /ud5t1 ! au?ors ( ?is text1 aft] an exp]i5ce ( _m ye>s1 _c help believ+ t ! t5d5cy has be5 r 9 ! o!r direction4 ,9 _m texts no m5tion at all is made ( fundam5tal laws ( *emical action because _! complete pres5tation is q beyond ! compreh5sion ( ! /ud5t1 :]eas 9 _m cases x is possible to pres5t ! ess5tial features ( ^! laws 9 a way t w be ( real assi/ance 9 ! und]/&+ ( ! sci5ce4 ,= example1 x is a difficult matt] to d$uce ! law ( mass action 9 any v simple way2 yet ! elem5t>y /ud5t c readily compreh5d t reactions are rev]sible1 & t ! po9t ( equilibrium dep5ds ^u1 r simple conditions4 ,! au?ors believe t x is wor? :ile to pres5t su* pr9ciples 9 ev5 an elem5t>y & p>tial mann] because !y are ( great assi/ance to ! g5]al /ud5t1 & because !y make a f\ndation ^u :i* ! /ud5t :o cont9ues 8 /udies to m advanc$ c\rses c securely build4 ,! au?ors h no apologies to make = ! ext5t to :i* !y h made use ( ! !ory ( electrolytic dissociation4 ,x is inevitable t 9 any rapidly develop+ sci5ce !re w be diff]5ces ( op9ion 9 reg>d to ! value ( c]ta9 !ories4 ,!re c be no "q1 h[ev]1 t ! outl9e ( ! !ory ( dissociation "h pres5t$ is 9 accord ) ! views ( ! v great majority ( ! *emi/s ( ! pres5t "t4 ,moreov]1 its introduction to ! ext5t to :i* ! au?ors h pres5t$ x simplifies r ?an increases ! difficulties ) :i* ! developm5t ( ! pr9ciples ( ! sci5ce is att5d$4 ,! oxyg5 /&>d = atomic weights has be5 adopt$ ?r\gh\t ! text4 ,! ,int]national ,committee1 to :i* is assign$ ! duty ( ye>ly report+ a revis$ li/ ( ! atomic weights ( ! elem5ts1 has adopt$ ?is /&>d = _! report1 & !re is no long] any au?ority = ! old] hydrog5 /&>d4 ,! au?ors d n believe t ! adoption ( ! oxyg5 /&>d introduces any real difficulties 9 mak+ p]fectly cle> ! me?ods by :i* atomic weights are calculat$4 ,! problems app5d$ to ! v>i\s *apt]s h be5 *os5 ) a view n only ( fix+ ! pr9ciples develop$ 9 ! text 9 ! m9d ( ! /ud5t1 b also ( enabl+ him to answ] su* que/ions z arise 9 8 laboratory "w4 ,!y are1 !re=e1 m or less practical 9 "*4 ,x is n necess>y t all ( !m %\ld be solv$1 ?\gh ) few exceptions ! li/s are n long4 ,! answ]s to ! que/ions are n directly giv5 9 ! text z a rule1 b c be inf]r$ f ! /atem5ts made4 ,!y !re=e require indep5d5t ?\ght on ! "p ( ! /ud5t4 ,) v few exceptions only su* exp]im5ts are includ$ 9 ! text z _c be easily c>ri$ out by ! /ud5t4 ,x is expect$ t ^! w be p]=m$ by ! tea*] at ! lecture table4 ,directions = laboratory "w by ! /ud5t are publi%$ 9 a sep>ate volume4 ,:ile ! au?ors believe t ! mo/ important function ( ! elem5t>y text is to develop ! pr9ciples ( ! sci5ce1 !y recognize ! importance ( "s discussion ( ! practical application ( ^! pr9ciples to our ev]yday life4 ,consid]able space is !re=e devot$ to ?is phase ( *emi/ry4 ,! tea*] %\ld supplem5t ?is discussion :5ev] possible by hav+ ! class visit diff]5t factories :]e *emical processes are employ$4 ,al?\gh ?is text is n[ = ! fir/ "t (f]$ to tea*]s ( elem5t>y *emi/ry1 x has nev]!less be5 us$ by a numb] ( tea*]s dur+ ! pa/ ?ree ye>s4 ,! pres5t edition has be5 l>gely rewritt5 9 ! light ( ! criticisms (f]$1 & we desire to express our ?anks to ! _m tea*]s :o h help$ u 9 ?is respect1 especially to ,dr4 ,william ,lloyd ,evans ( ?is laboratory1 a tea*] ( wide exp]i5ce1 = 8 cont9u$ int]e/ & helpfulness4 ,we also v cordially solicit correspond5ce ) tea*]s :o may f9d difficulties or inaccuracies 9 ! text4 ,! au?ors wi% to make ackn[l$gm5ts = ! photographs & engrav+s ( em95t *emi/s f :i* ! cuts includ$ 9 ! text 7 tak52 to ,messrs4 ,elliott & ,fry1 ,london1 ,engl&1 = t ( ,ramsay2 to ,! ,macmillan ,company = ^? ( ,davy & ,dalton1 tak5 f ! ,c5tury ,sci5ce ,s]ies2 to ! ,l4 ,e4 ,knott ,app>atus ,company1 ,bo/on1 = t ( ,buns54 ,,! ,,au?ors ,,ohio ,,/ate ,,univ]sity ,,columbus1 ,,ohio ,,cont5ts ,,*apt] ,,page ,i4 ,,introduction #a ,,ii4 ,,oxyg5 #ac ,,iii4 ,,hydrog5 #bh ,,iv4 ,,wat] ,,& ,,hydrog5 ,,dioxide #dj ,v4 ,,! ,,atomic ,,!ory #ei ,,vi4 ,,*emical ,,equations ,,& ,,calculations #fh ,,vii4 ,,nitrog5 ,,& ,,! ,,r>e ,,elem5ts ,,9 ,,! ,,atmosph]e #gh ,,viii4 ,,! ,,atmosph]e #hc ,,ix4 ,,solutions #id ,x4 ,,acids1 ,,bases1 ,,& ,,salts2 ,,neutralization #ajf ,,xi4 ,,val5ce #aaf ,,xii4 ,,comp\nds ,,( ,,nitrog5 #abb ,,xiii4 ,,rev]sible ,,reactions ,,& ,,*emical ,,equilibrium #acg ,,xiv4 ,,sulphur ,,& ,,its ,,comp\nds #adc ,,xv4 ,,p]iodic ,,law #afe ,,xvi4 ,,! ,,*lor9e ,,family #agd ,,xvii4 ,,c>bon ,,& ,,"s ,,( ,,its ,,simpl] ,,comp\nds #aif ,,xviii4 ,,flames1--,,illum9ants #bac ,,xix4 ,,molecul> ,,weights1 ,,atomic ,,weights1 ,,=mulas #bbc ,,xx4 ,,! ,,phosphorus ,,family #bch ,,xxi4 ,,silicon1 ,,titanium1 ,,boron #beg ,,xxii4 ,,! ,,metals #bfg ,,xxiii4 ,,! ,,alkali ,,metals #bgd ,,xxiv4 ,,! ,,alkal9e-,,e>? ,,family #cjj ,,xxv4 ,,! ,,magnesium ,,family #caf ,,xxvi4 ,,! ,,alum9ium ,,family #cbg ,,xxvii4 ,,! ,,iron ,,family #cch ,,xxviii4 ,,copp]1 ,,m]cury1 ,,& ,,silv] #cef ,,xxix4 ,,t9 ,,& ,,lead #cgj ,,xxx4 ,,manganese ,,& ,,*romium #cgi ,,xxxi4 ,,gold ,,& ,,! ,,plat9um ,,family #cij ,,xxxii4 ,,"s ,,simple ,,organic ,,comp\nds #cig ,,index #dba ,,app5dix ,a ,fac+ back cov] ,,app5dix ,b ,inside back cov] ,,li/ ,,( ,,full-,,page ,,illu/rations ,,page ,,anto9e ,,laur5t ,,lavoisi] ,frontispiece ,,joseph ,,prie/ley #ad ,,john ,,dalton #fj ,,william ,,ramsay #hb ,,dmitri ,,ivanovit* ,,m5del,,eff #aff ,,h5ri ,,moissan #agf ,,sir ,,humphry ,,davy #bgf ,,rob]t ,,wilhelm ,,buns5 #bih ,,an ,,elem5t>y ,,/udy ,,( ,,*emi/ry ,,*apt] ,i ,,introduction ,! natural sci5ces4 ,be=e we advance v f> 9 ! /udy ( nature1 x becomes evid5t t ! "o l>ge /udy mu/ be divid$ into a numb] ( m limit$ ones = ! conv5i5ce ( ! inve/igator z well z ( ! /ud5t4 ,^! m limit$ /udies are call$ ! natural sci5ces4 ,s9ce ! /udy ( nature is divid$ 9 ?is way = m]e conv5i5ce1 & n because !re is any division 9 nature itself1 x (t5 happ5s t ! diff]5t sci5ces are v intimately relat$1 & a ?or\gh k ( any "o ( !m involves a consid]able acqua9tance ) sev]al o!rs4 ,?us ! botani/ mu/ "k some?+ ab\t animals z well z ab\t plants2 ! /ud5t ( human physiology mu/ "k some?+ ab\t physics z well z ab\t ! p>ts ( ! body4 ,intimate relation ( *emi/ry & physics4 ,physics & *emi/ry are two sci5ces relat$ 9 ?is close way1 & x is n easy to make a precise di/9ction betwe5 !m4 ,9 a g5]al way x may be said t !y are bo? conc]n$ ) inanimate matt] r ?an ) liv+1 & m p>ticul>ly ) ! *anges :i* su* matt] may be made to und]go4 ,^! *anges mu/ be consid]$ m closely be=e a def9ition ( ! two sci5ces c be giv54 ,physical *anges4 ,"o class ( *anges is n accompani$ by an alt]ation 9 ! composition ( matt]4 ,:5 a lump ( coal is brok5 ! pieces d n diff] f ! orig9al lump save 9 size4 ,a rod ( iron may be brok5 into pieces2 x may be magnetiz$2 x may be heat$ until x gl[s2 x may be melt$4 ,9 none ( ^! *anges has ! composition ( ! iron be5 affect$4 ,! pieces ( iron1 ! magnetiz$ iron1 ! gl[+ iron1 ! melt$ iron1 are j z truly iron z 0 ! orig9al rod4 ,sug> may be dissolv$ 9 wat]1 b nei!r ! sug> nor ! wat] is *ang$ 9 composition4 ,! result+ liquid has ! sweet ta/e ( sug>2 moreov] ! wat] may be evaporat$ by heat+ & ! sug> recov]$ un*ang$4 ,su* *anges are call$ physical *anges4 ,,def9ition3 ,physical *anges are ^? :i* d n involve a *ange 9 ! composition ( ! matt]4 ,*emical *anges4 ,matt] may und]go o!r *anges 9 :i* its composition is alt]$4 ,:5 a lump ( coal is burn$ a%es & invisible gases are =m$ :i* are entirely diff]5t 9 composition & prop]ties f ! orig9al coal4 ,a rod ( iron :5 expos$ to moi/ air is gradually *ang$ into ru/1 :i* is entirely diff]5t f ! orig9al iron4 ,:5 sug> is heat$ a black sub/ance is =m$ :i* is nei!r sweet nor soluble 9 wat]4 ,su* *anges are evid5tly q diff]5t f ! physical *anges j describ$1 = 9 !m new sub/ances are =m$ 9 place ( ! ones und]go+ *ange4 ,*anges ( ?is k9d are call$ *emical *anges4 ,,def9ition3 ,*emical *anges are ^? :i* involve a *ange 9 ! composition ( ! matt]4 ,h[ to di/+ui% betwe5 physical & *emical *anges4 ,x is n always easy to tell to :i* class a giv5 *ange belongs1 & _m cases w require c>eful ?\ght on ! "p ( ! /ud5t4 ,! te/ "q 9 all cases is1 ,has ! composition ( ! sub/ance be5 *ang$8 ,usually ?is c be answ]$ by a /udy ( ! prop]ties ( ! sub/ance be=e & aft] ! *ange1 s9ce a *ange 9 composition is att5d$ by a *ange 9 prop]ties4 ,9 "s cases1 h[ev]1 only a tra9$ obs]v] c decide ! "q4 ,*anges 9 physical /ate4 ,"o class ( physical *anges %\ld be not$ ) especial c>e1 s9ce x is likely to prove mislead+4 ,x is a famili> fact t ice is *ang$ into wat]1 & wat] into /eam1 by heat+4 ,"h we h ?ree diff]5t sub/ances1--! solid ice1 ! liquid wat]1 & ! gase\s /eam1--! prop]ties ( :i* diff] widely4 ,! *emi/ c readily %[1 h[ev]1 t ^! ?ree bodies h exactly ! same composition1 be+ compos$ ( ! same sub/ances 9 ! same proportion4 ,h5ce ! *ange f "o ( ^! sub/ances into ano!r is a physical *ange4 ,_m o!r sub/ances may1 "u suitable conditions1 be *ang$ f solids into liquids1 or f liquids into gases1 )\t *ange 9 composition4 ,?us butt] & wax w melt :5 heat$2 alcohol & gasol9e w evaporate :5 expos$ to ! air4 ,! ?ree /ates--solid1 liquid1 & gas--are call$ ! ?ree physical /ates ( matt]4 ,physical & *emical prop]ties4 ,_m prop]ties ( a sub/ance c be not$ )\t caus+ ! sub/ance to und]go *emical *ange1 & are !re=e call$ its physical prop]ties4 ,among ^! are its physical /ate1 color1 odor1 ta/e1 size1 %ape1 weight4 ,o!r prop]ties are only discov]$ :5 ! sub/ance und]goes *emical *ange4 ,^! are call$ its *emical prop]ties4 ,?us we f9d t coal burns 9 air1 gunp[d] explodes :5 ignit$1 milk s\rs :5 expos$ to air4 ,def9ition ( physics & *emi/ry4 ,x is n[ possible to make a g5]al di/9ction betwe5 physics & *emi/ry4 ,,def9ition3 ,physics is ! sci5ce :i* deals ) ^? *anges 9 matt] :i* d n involve a *ange 9 composition4 ,,def9ition3 ,*emi/ry is ! sci5ce :i* deals ) ^? *anges 9 matt] :i* d involve a *ange 9 composition4 ,two factors 9 all *anges4 ,9 all ! *anges :i* matt] c und]go1 :e!r physical or *emical1 two factors mu/ be tak5 into acc\nt1 namely1 en]gy & matt]4 ,en]gy4 ,x is a famili> fact t c]ta9 bodies h ! p[] to d "w4 ,?us wat] fall+ f a height ^u a wat] :eel turns ! :eel & 9 ?is way does ! "w ( ! mills4 ,magnetiz$ iron attracts iron to itself & ! motion ( ! iron z x moves t[>ds ! magnet c be made to d "w4 ,:5 coal is burn$ x causes ! eng9e to move & transports ! load$ c>s f place to place4 ,:5 a body has ?is p[] to d "w x is said to possess en]gy4 ,law ( cons]vation ( en]gy4 ,c>eful exp]im5ts h %[n t :5 "o body p>ts ) its en]gy ! en]gy is n de/roy$ b is transf]r$ to ano!r body or sy/em ( bodies4 ,j z en]gy _c be de/roy$1 nei!r c x be creat$4 ,if "o body ga9s a c]ta9 am\nt ( en]gy1 "s o!r body has lo/ an equival5t am\nt4 ,^! facts are summ$ up 9 ! law ( cons]vation ( en]gy :i* may be /at$ ?us3 ,:ile en]gy c be *ang$ f "o =m into ano!r1 x _c be creat$ or de/roy$4 ,trans=mations ( en]gy4 ,al?\gh en]gy c nei!r be creat$ nor de/roy$1 x is evid5t t x may assume _m diff]5t =ms4 ,?us ! fall+ wat] may turn ! electric g5]ator & produce a curr5t ( electricity4 ,! en]gy lo/ by ! fall+ wat] is ?us trans=m$ into ! en]gy ( ! electric curr5t4 ,?is 9 turn may be *ang$ into ! en]gy ( motion1 z :5 ! curr5t is us$ = propell+ ! c>s1 or into ! en]gy ( heat & light1 z :5 x is us$ = heat+ & light+ ! c>s4 ,aga91 ! en]gy ( coal may be conv]t$ into en]gy ( heat & subsequ5tly ( motion1 z :5 x is us$ z a fuel 9 /eam eng9es4 ,s9ce ! en]gy possess$ by coal only becomes available :5 ! coal is made to und]go a *emical *ange1 x is sometimes call$ *emical en]gy4 ,x is ?is =m ( en]gy 9 :i* we are especially int]e/$ 9 ! /udy ( *emi/ry4 ,matt]4 ,matt] may be def9$ z t :i* occupies space & possesses weight4 ,l en]gy1 matt] may be *ang$ (t5times f "o =m into ano!r2 & s9ce 9 ^! trans=mations all ! o!r physical prop]ties ( a sub/ance save weight are likely to *ange1 ! inquiry arises1 ,does ! weight also *ange8 ,mu* c>eful exp]im5t+ has %[n t x does n4 ,! weight ( ! products =m$ 9 any *ange 9 matt] always equals ! weight ( ! sub/ances und]go+ *ange4 ,law ( cons]vation ( matt]4 ,! important tru? j /at$ is frequ5tly ref]r$ to z ! law ( cons]vation ( matt]1 & ?is law may be briefly /at$ ?us3 ,matt] c nei!r be creat$ nor de/roy$1 ?\gh x c be *ang$ f "o =m into ano!r4 ,classification ( matt]4 ,at fir/ sight !re appe>s to be no limit to ! v>ieties ( matt] ( :i* ! _w is made4 ,= conv5i5ce 9 /udy we may classify all ^! v>ieties "u ?ree heads1 namely1 me*anical mixtures1 *emical comp\nds1 & elem5ts4 ,illu/ration3 ,fig4 #a ,me*anical mixtures4 ,if equal bulks ( common salt & iron fil+s are ?or\ghly mix$ toge!r1 a product is obta9$ :i*1 judg+ by its appe>ance1 is a new sub/ance4 ,if x is exam9$ m closely1 h[ev]1 x w be se5 to be m]ely a mixture ( ! salt & iron1 ea* ( :i* sub/ances reta9s its own peculi> prop]ties4 ,! mixture ta/es j l salt2 ! iron p>ticles c be se5 & _! gritty "* detect$4 ,a magnet rubb$ 9 ! mixture draws out ! iron j z if ! salt 7 n !re4 ,on ! o!r h&1 ! salt c be sep>at$ f ! iron q easily4 ,?us1 if sev]al grams ( ! mixture are plac$ 9 a te/ tube1 & ! tube half fill$ ) wat] & ?or\ghly %ak51 ! salt dissolves 9 ! wat]4 ,! iron p>ticles c !n be filt]$ f ! liquid by p\r+ ! entire mixture ^u a piece ( filt] pap] fold$ s z to fit into ! int]ior ( a funnel 7,fig4 #a74 ,! pap] reta9s ! solid b all[s ! cle> liquid1 kn[n z ! filtrate1 to dra9 ?r\gh4 ,! iron p>ticles left ^u ! filt] pap] w be f\nd to be id5tical ) ! orig9al iron4 ,! salt c be recov]$ f ! filtrate by evaporation ( ! wat]4 ,to accompli% ?is ! filtrate is p\r$ into a small evaporat+ di% & g5tly heat$ 7,fig4 #b7 until ! wat] has disappe>$1 or evaporat$4 ,! solid left 9 ! di% is id5tical 9 e way ) ! orig9al salt4 ,bo? ! iron & ! salt h ?us be5 recov]$ 9 _! orig9al condition4 ,x is evid5t t no new sub/ance has be5 =m$ by rubb+ ! salt & iron toge!r4 ,! product is call$ a me*anical mixture4 ,su* mixtures are v common 9 nature1 almo/ all m9]als1 s&s1 & soils be+ examples ( ?is class ( sub/ances4 ,x is at once app>5t t !re is no law regulat+ ! composition ( a me*anical mixture1 & no two mixtures are likely to h exactly ! same composition4 ,! +r$i5ts ( a me*anical mixture c usually be sep>at$ by me*anical means1 su* z sift+1 sort+1 magnetic attraction1 or by dissolv+ "o con/itu5t & leav+ ! o!r un*ang$4 ,illu/ration3 ,fig4 #b ,,def9ition3 ,a me*anical mixture is "o 9 :i* ! con/itu5ts reta9 _! orig9al prop]ties1 no *emical action hav+ tak5 place :5 !y 7 br\ght toge!r4 ,*emical comp\nds4 ,if iron fil+s & p[d]$ sulphur are ?or\ghly gr\nd toge!r 9 a mort>1 a yell[i%-gre5 sub/ance results4 ,x might easily be tak5 to be a new body2 b z 9 ! case ( ! iron & salt1 ! +r$i5ts c readily be sep>at$4 ,a magnet draws out ! iron4 ,wat] does n dissolve ! sulphur1 b o!r liquids d1 z1 = example1 ! liquid call$ c>bon disulphide4 ,:5 ! mixture is treat$ ) c>bon disulphide ! iron is left un*ang$1 & ! sulphur c be obta9$ aga91 aft] filt]+ (f ! iron1 by evaporat+ ! liquid4 ,! sub/ance is1 !re=e1 a me*anical mixture4 ,if n[ a new portion ( ! mixture is plac$ 9 a dry te/ tube & c>efully heat$ 9 ! flame ( a ,buns5 burn]1 z %[n 9 ,fig4 #c1 a /rik+ *ange takes place4 ,! mixture beg9s to gl[ at "s po9t1 ! gl[ rapidly ext5d+ ?r\gh\t ! :ole mass4 ,if ! te/ tube is n[ brok5 & ! product exam9$1 x w be f\nd to be a h>d1 black1 brittle sub/ance1 9 no way recall+ ! iron or ! sulphur4 ,! magnet no long] attracts x2 c>bon disulphide w n dissolve sulphur f x4 ,x is a new sub/ance ) new prop]ties1 result+ f ! *emical union ( iron & sulphur1 & is call$ iron sulphide4 ,su* sub/ances are call$ *emical comp\nds1 & diff] f me*anical mixtures 9 t ! sub/ances produc+ !m lose _! own *>act]i/ic prop]ties4 ,we %all see lat] t ! two also diff] 9 t ! composition ( a *emical comp\nd nev] v>ies4 ,illu/ration3 ,fig4 #c ,,def9ition3 ,a *emical comp\nd is a sub/ance ! con/itu5ts ( :i* h lo/ _! own *>act]i/ic prop]ties1 & :i* _c be sep>at$ save by a *emical *ange4 ,elem5ts4 ,x has be5 se5 t iron sulphide is compos$ ( two entirely diff]5t sub/ances1--iron & sulphur4 ,! "q arises1 ,d ^! sub/ances 9 turn conta9 o!r sub/ances1 t is1 are !y also *emical comp\nds8 ,*emi/s h tri$ 9 a great _m ways to decompose !m1 b all _! ef=ts h fail$4 ,sub/ances :i* h resi/$ all ef=ts to decompose !m into o!r sub/ances are call$ elem5ts4 ,x is n always easy to prove t a giv5 sub/ance is really an elem5t4 ,"s way z yet untri$ may be successful 9 decompos+ x into o!r simpl] =ms ( matt]1 & ! suppos$ elem5t w !n prove to be a comp\nd4 ,wat]1 lime1 & _m o!r famili> comp\nds 7 at "o "t ?\ght to be elem5ts4 ,,def9ition3 ,an elem5t is a sub/ance :i* _c be sep>at$ into simpl] sub/ances by any kn[n means4 ,k9ds ( matt]4 ,:ile matt] has be5 gr\p$ 9 ?ree classes = ! purpose ( /udy1 x w be app>5t t !re are really b two di/9ct k9ds ( matt]1 namely1 comp\nds & elem5ts4 ,a me*anical mixture is n a ?ird di/9ct k9d ( matt]1 b is made up ( v>y+ quantities ( ei!r comp\nds or elem5ts or bo?4 ,al*emy4 ,9 old5 times x 0 ?\ght t "s way c\ld be f\nd to *ange "o elem5t into ano!r1 & a great _m ef=ts 7 made to accompli% ?is trans=mation4 ,mo/ ( ^! ef=ts 7 direct$ t[>d *ang+ ! common] metals into gold1 & _m fanciful ways = do+ ?is 7 describ$4 ,! *emi/s ( t "t 7 call$ al*emi/s1 & ! art :i* !y practic$ 0 call$ al*emy4 ,! al*emi/s gradually became conv9c$ t ! only way common metals c\ld be *ang$ into gold 0 by ! wond]ful p[] ( a magic sub/ance :i* !y call$ ! philosoph]'s /one1 :i* w\ld accompli% ?is trans=mation by its m]e t\* & w\ld 9 addition give p]petual y\? to its =tunate possessor4 ,no "o has ev] f\nd su* a /one1 & no "o has succe$$ 9 *ang+ "o metal into ano!r4 ,numb] ( elem5ts4 ,! numb] ( sub/ances n[ consid]$ to be elem5ts is n l>ge--ab\t eighty 9 all4 ,_m ( ^! are r>e1 & v few ( !m make any l>ge fraction ( ! mat]ials 9 ! e>?'s cru/4 ,cl>ke gives ! foll[+ e/imate ( ! composition ( ! e>?'s cru/3 ,oxyg5 #dg4j ,calcium #c4e ,silicon #bg4i ,magnesium #b4e ,alum9ium #h4a ,sodium #b4g ,iron #d4g ,potassium #b4d ,o!r elem5ts #a4b ,a complete li/ ( ! elem5ts is giv5 9 ! ,app5dix4 ,9 ?is li/ ! m common ( ! elem5ts are m>k$ ) an a/]isk4 ,x is n necess>y to /udy m ?an a ?ird ( ! total numb] ( elem5ts to ga9 a v good k ( *emi/ry4 ,physical /ate ( ! elem5ts4 ,ab\t t5 ( ! elem5ts are gases at ord9>y temp]atures4 ,two--m]cury & brom9e--are liquids4 ,! o!rs are all solids1 ?\gh _! melt+ po9ts v>y ?r\gh wide limits1 f csium :i* melts at #bf to elem5ts :i* d n melt save 9 ! int5se heat ( ! electric furnace4 ,occurr5ce ( ! elem5ts4 ,comp>atively few ( ! elem5ts occur z uncomb9$ sub/ances 9 nature1 mo/ ( !m be+ f\nd 9 ! =m ( *emical comp\nds4 ,:5 an elem5t does occur by itself1 z is ! case ) gold1 we say t x occurs 9 ! free /ate or native2 :5 x is comb9$ ) o!r sub/ances 9 ! =m ( comp\nds1 we say t x occurs 9 ! comb9$ /ate1 or 9 comb9ation4 ,9 ! latt] case !re is usually little ab\t ! comp\nd to sugge/ t ! elem5t is pres5t 9 x2 = we h se5 t elem5ts lose _! own peculi> prop]ties :5 !y ent] into comb9ation ) o!r elem5ts4 ,x w\ld nev] be suspect$1 = example1 t ! r$di%1 e>?y-look+ iron ore conta9s iron4 ,names ( elem5ts4 ,! names giv5 to ! elem5ts h be5 select$ 9 a great _m diff]5t ways4 7#a7 ,"s names are v old & _! orig9al mean+ is obscure4 ,su* names are iron1 gold1 & copp]4 7#b7 ,_m names indicate "s /rik+ physical prop]ty ( ! elem5t4 ,! "n brom9e1 = example1 is d]iv$ f a ,greek ^w mean+ a /5*1 ref]r+ to ! extremely unpleasant odor ( ! sub/ance4 ,! "n iod9e comes f a ^w mean+ violet1 allud+ to ! beautiful color ( iod9e vapor4 7#c7 ,"s names indicate prom95t *emical prop]ties ( ! elem5ts4 ,?us1 nitrog5 means ! produc] ( nit]1 nitrog5 be+ a con/itu5t ( nit] or saltpet]4 ,hydrog5 means wat] =m]1 signify+ its pres5ce 9 wat]4 ,argon means lazy or in]t1 ! elem5t be+ s nam$ because ( its inactivity4 7#d7 ,o!r elem5ts are nam$ f c\ntries or localities1 z g]manium & sc&ium4 ,symbols4 ,9 indicat+ ! elem5ts f\nd 9 comp\nds x is inconv5i5t to use su* long names1 & h5ce *emi/s h adopt$ a sy/em ( abbreviations4 ,^! abbreviations are kn[n z symbols1 ea* elem5t hav+ a di/9ctive symbol4 7#a7 ,sometimes ! initial lett] ( ! "n w suffice to indicate ! elem5t4 ,?us ,i /&s = iod9e1 ,c = c>bon4 7#b7 ,usually x is necess>y to add "s o!r *>act]i/ic lett] to ! symbol1 s9ce sev]al names may beg9 ) ! same lett]4 ,?us ,c /&s = c>bon1 ,cl = *lor9e1 ,cd = cadmium1 ,ce = c]ium1 ,cb = columbium4 7#c7 ,sometimes ! symbol is an abbreviation ( ! old ,lat9 "n4 ,9 ?is way ,fe 7f]rum7 indicates iron1 ,cu 7cuprum71 copp]1 ,au 7aurum71 gold4 ,! symbols are includ$ 9 ! li/ ( elem5ts giv5 9 ! ,app5dix4 ,!y w become famili> ?r\gh con/ant use4 ,*emical aff9ity ! cause ( *emical comb9ation4 ,! ag5cy :i* causes sub/ances to comb9e & :i* holds !m toge!r :5 comb9$ is call$ *emical aff9ity4 ,! exp]im5ts describ$ 9 ?is *apt]1 h[ev]1 %[ t heat is (t5 necess>y to br+ ab\t *emical action4 ,! di/9ction betwe5 ! cause produc+ *emical action & ! circum/ances favor+ x mu/ be cle>ly made4 ,*emical aff9ity is always ! cause ( *emical union4 ,_m ag5cies may make x possible = *emical aff9ity to act by ov]com+ circum/ances :i* /& 9 its way4 ,among ^! ag5cies are heat1 light1 & electricity4 ,z a rule1 solution also promotes action betwe5 two sub/ances4 ,sometimes ^! ag5cies may ov]come *emical attraction & s occasion ! decomposition ( a comp\nd4 ,,ex]cises #a4 ,to :at class ( *anges d ! foll[+ belong8 7a7 ,! melt+ ( ice2 7b7 ! s\r+ ( milk2 7c7 ! burn+ ( a c&le2 7d7 ! explosion ( gunp[d]2 7e7 ! corrosion ( metals4 ,:at te/ "q mu/ be appli$ 9 ea* ( ! above cases8 #b4 ,give two additional examples 7a7 ( *emical *anges2 7b7 ( physical *anges4 #c4 ,is a *emical *ange always accompani$ by a physical *ange8 ,is a physical *ange always accompani$ by a *emical *ange8 #d4 ,give two or m *>act]i/ics ( a *emical *ange4 #e4 7a7 ,:5 a giv5 weight ( wat] freezes1 does x absorb or evolve heat8 7b7 ,:5 ! result+ ice melts1 is ! total heat *ange ! same or diff]5t f t ( freez+8 #f4 ,give ?ree examples ( ea* ( ! foll[+3 7a7 me*anical mixtures2 7b7 *emical comp\nds2 7c7 elem5ts4 #g4 ,give ! d]ivation ( ! names ( ! foll[+ elem5ts3 ?orium1 gallium1 sel5ium1 uranium4 7,consult diction>y47 #h4 ,give examples ( *emical *anges :i* are produc$ ?r\gh ! ag5cy ( heat2 ( light2 ( electricity4 ,,*apt] ,,ii ,,oxyg5 ,hi/ory4 ,! discov]y ( oxyg5 is g5]ally attribut$ to ! ,engli% *emi/ ,prie/ley1 :o 9 #aggd obta9$ ! elem5t by heat+ a comp\nd ( m]cury & oxyg51 kn[n z r$ oxide ( m]cury4 ,x is probable1 h[ev]1 t ! ,sw$i% *emi/ ,s*eele _h previ\sly obta9$ x1 al?\gh an acc\nt ( 8 exp]im5ts 0 n publi%$ until #aggg4 ,! "n oxyg5 signifies acid =m]4 ,x 0 giv5 to ! elem5t by ! ,fr5* *emi/ ,lavoisi]1 s9ce he believ$ t all acids owe _! *>act]i/ic prop]ties to ! pres5ce ( oxyg54 ,?is view we n[ "k to be incorrect4 ,occurr5ce4 ,oxyg5 is by f> ! mo/ abundant ( all ! elem5ts4 ,x occurs bo? 9 ! free & 9 ! comb9$ /ate4 ,9 ! free /ate x occurs 9 ! air1 #ajj volumes ( dry air conta9+ ab\t #ba volumes ( oxyg54 ,9 ! comb9$ /ate x =ms eight n9?s ( wat] & ne>ly "o half ( ! rocks compos+ ! e>?'s cru/4 ,x is also an important con/itu5t ( ! comp\nds :i* compose plant & animal tissues2 = example1 ab\t #ff by weight ( ! human body is oxyg54 ,prep>ation4 ,al?\gh oxyg5 occurs 9 ! free /ate 9 ! atmosph]e1 its sep>ation f ! nitrog5 & o!r gases ) :i* x is mix$ is su* a difficult matt] t 9 ! laboratory x has be5 f\nd m conv5i5t to prep>e x f its comp\nds4 ,! mo/ important ( ! laboratory me?ods are ! foll[+3 #a4 ,prep>ation f wat]4 ,wat] is a comp\nd1 consi/+ ( #aa4ah hydrog5 & #hh4hb oxyg54 ,x is easily sep>at$ into ^! con/itu5ts by pass+ an electric curr5t ?r\gh x "u suitable conditions4 ,! process w be describ$ 9 ! *apt] on wat]4 ,:ile ?is me?od ( prep>ation is a simple "o1 x is n economical4 #b4 ,prep>ation f m]curic oxide4 ,?is me?od is ( int]e/1 s9ce x is ! "o :i* l$ to ! discov]y ( oxyg54 ,! oxide1 :i* consi/s ( #g4d oxyg5 & #ib4f m]cury1 is plac$ 9 a small1 glass te/ tube & heat$4 ,! comp\nd is 9 ?is way decompos$ into m]cury :i* collects on ! sides ( ! glass tube1 =m+ a silv]y mirror1 & oxyg5 :i*1 be+ a gas1 escapes f ! tube4 ,! pres5ce ( ! oxyg5 is %[n by light+ ! end ( a spl9t1 ext+ui%+ ! flame & br++ ! gl[+ coal into ! m\? ( ! tube4 ,! oxyg5 causes ! gl[+ coal to bur/ into a flame4 ,9 a simil> way oxyg5 may be obta9$ f its comp\nds ) "s ( ! o!r elem5ts4 ,?us manganese dioxide1 a black comp\nd ( manganese & oxyg51 :5 heat$ to ab\t #gjj1 loses "o ?ird ( its oxyg51 :ile b>ium dioxide1 :5 heat$1 loses "o half ( its oxyg54 #c4 ,prep>ation f potassium *lorate 7usual laboratory me?od74 ,potassium *lorate is a :ite solid :i* consi/s ( #ca4i potassium1 #bh4i *lor9e1 & #ci4b oxyg54 ,:5 heat$ x und]goes a s]ies ( *anges 9 :i* all ! oxyg5 is f9ally set free1 leav+ a comp\nd ( potassium & *lor9e call$ potassium *loride4 ,! *ange may be repres5t$ z foll[s3 _/potassium 7potassium _/ potassium 7potassium *lor9e oxyg5 *lorate7 *lor9e _/ *loride7 oxyg5 _/ ,illu/ration3 ,,joseph ,,prie/ley 7,engli%7 7#agcc-ahjd7 ,s*ool-tea*]1 !ologian1 philosoph]1 sci5ti/2 fri5d ( ,b5jam9 ,frankl92 discov]] ( oxyg52 def5d] ( ! phlogi/on !ory2 ! fir/ to use m]cury 9 a pneumatic tr\gh1 by :i* means he fir/ isolat$ 9 gase\s =m hydro*loric acid1 sulphur dioxide1 & ammonia ,! evolution ( ! oxyg5 beg9s at ab\t #djj4 ,x has be5 f\nd1 h[ev]1 t if ! potassium *lorate is mix$ ) ab\t "o f\r? its weight ( manganese dioxide1 ! oxyg5 is giv5 (f at a mu* l[] temp]ature4 ,j h[ ! manganese dioxide br+s ab\t ?is result is n def9itely kn[n4 ,! am\nt ( oxyg5 obta9$ f a giv5 weight ( potassium *lorate is exactly ! same :e!r ! manganese dioxide is pres5t or n4 ,s f> z c be detect$ ! manganese dioxide und]goes no *ange4 ,illu/ration3 ,fig4 #d ,directions = prep>+ oxyg54 ,! mann] ( prep>+ oxyg5 f potassium *lorate is illu/rat$ 9 ! accompany+ diagram 7,fig4 #d74 ,a mixture consi/+ ( "o "p ( manganese dioxide & f\r p>ts ( potassium *lorate is plac$ 9 ! flask ,a & g5tly heat$4 ,! oxyg5 is evolv$ & escapes ?r\gh ! tube ,b4 ,x is collect$ by br++ ov] ! end ( ! tube ! m\? ( a bottle completely fill$ ) wat] & inv]t$ 9 a vessel ( wat]1 z %[n 9 ! figure4 ,! gas rises 9 ! bottle & displaces ! wat]4 ,9 ! prep>ation ( l>ge quantities ( oxyg51 a copp] retort 7,fig4 #e7 is (t5 sub/itut$ = ! glass flask4 ,illu/ration3 ,fig4 #e ,9 ! prep>ation ( oxyg5 f potassium *lorate & manganese dioxide1 ! mat]ials us$ mu/ be pure1 o!rwise a viol5t explosion may occur4 ,! purity ( ! mat]ials is te/$ by heat+ a small am\nt ( ! mixture 9 a te/ tube4 ,! collection ( gases4 ,! me?od us$ = collect+ oxyg5 illu/rates ! g5]al me?od us$ = collect+ su* gases z are insoluble 9 wat] or ne>ly s4 ,! vessel ,c 7,fig4 #d71 conta9+ ! wat] 9 :i* ! bottles are inv]t$1 is call$ a pneumatic tr\gh4 ,comm]cial me?ods ( prep>ation4 ,oxyg5 c n[ be pur*as$ /or$ "u great pressure 9 /rong /eel cyl9d]s 7,fig4 #f74 ,x is prep>$ ei!r by heat+ a mixture ( potassium *lorate & manganese dioxide1 or by sep>at+ x f ! nitrog5 & o!r gases ) :i* x is mix$ 9 ! atmosph]e4 ,! me?ods employ$ = effect+ ?is sep>ation w be describ$ 9 subsequ5t *apt]s4 ,illu/ration3 ,fig4 #f ,physical prop]ties4 ,oxyg5 is a colorless1 odorless1 ta/eless gas1 slightly heavi] ?an air4 ,"o lit] ( x1 measur$ at a temp]ature ( #j & "u a pressure ( "o atmosph]e1 weighs #a4dbhe g41 :ile "u simil> conditions "o lit] ( air weighs #a4bibc g4 ,x is b slightly soluble 9 wat]4 ,oxyg51 l o!r gases1 may be liquefi$ by apply+ v great pressure to ! highly cool$ gas4 ,:5 ! pressure is remov$ ! liquid oxyg5 passes aga9 into ! gase\s /ate1 s9ce its boil+ po9t "u ord9>y atmosph]ic pressure is -#ahb4e4 ,*emical prop]ties4 ,at ord9>y temp]atures oxyg5 is n v active *emically4 ,mo/ sub/ances are ei!r n at all affect$ by x1 or ! action is s sl[ z to escape notice4 ,at high] temp]atures1 h[ev]1 x is v active1 & unites directly ) mo/ ( ! elem5ts4 ,?is activity may be %[n by heat+ v>i\s sub/ances until j ignit$ & !n br++ !m into vessels ( ! gas1 :5 !y w burn ) great brilliancy4 ,?us a gl[+ spl9t introduc$ into a j> ( oxyg5 bur/s into flame4 ,sulphur burns 9 ! air ) a v weak flame & feeble light2 9 oxyg51 h[ev]1 ! flame is increas$ 9 size & brightness4 ,sub/ances :i* readily burn 9 air1 su* z phosphorus1 burn 9 oxyg5 ) dazzl+ brilliancy4 ,ev5 sub/ances :i* burn 9 air ) great difficulty1 su* z iron1 readily burn 9 oxyg54 ,! burn+ ( a sub/ance 9 oxyg5 is due to ! rapid comb9ation ( ! sub/ance or ( ! elem5ts compos+ x ) ! oxyg54 ,?us1 :5 sulphur burns bo? ! oxyg5 & sulphur disappe> z su* & !re is =m$ a comp\nd ( ! two1 :i* is an invisible gas1 hav+ ! *>act]i/ic odor ( burn+ sulphur4 ,simil>ly1 phosphorus on burn+ =ms a :ite solid comp\nd ( phosphorus & oxyg51 :ile iron =ms a r$di%-black comp\nd ( iron & oxyg54 ,oxidation4 ,! t]m oxidation is appli$ to ! *emical *ange :i* takes place :5 a sub/ance1 or "o ( its con/itu5t p>ts1 comb9es ) oxyg54 ,?is process may take place rapidly1 z 9 ! burn+ ( phosphorus1 or sl[ly1 z 9 ! oxidation 7or ru/+7 ( iron :5 expos$ to ! air4 ,x is always accompani$ by ! lib]ation ( heat4 ,! am\nt ( heat lib]at$ by ! oxidation ( a def9ite weight ( any giv5 sub/ance is always ! same1 be+ entirely indep5d5t ( ! rapidity ( ! process4 ,if ! oxidation takes place sl[ly1 ! heat is g5]at$ s sl[ly t x is difficult to detect x4 ,if ! oxidation takes place rapidly1 h[ev]1 ! heat is g5]at$ 9 su* a %ort int]val ( "t t ! sub/ance may become :ite hot or bur/ into a flame4 ,combu/ion2 k9dl+ temp]ature4 ,:5 oxidation takes place s rapidly t ! heat g5]at$ is suffici5t to cause ! sub/ance to gl[ or bur/ into a flame ! process is call$ combu/ion4 ,9 ord] t any sub/ance may und]go combu/ion1 x is necess>y t x %\ld be heat$ to a c]ta9 temp]ature1 kn[n z ! k9dl+ temp]ature4 ,?is temp]ature v>ies widely = diff]5t bodies1 b is always def9ite = ! same body4 ,?us ! k9dl+ temp]ature ( phosphorus is f> l[] ?an t ( iron1 b is def9ite = ea*4 ,:5 any portion ( a sub/ance is heat$ until x beg9s to burn ! combu/ion w cont9ue )\t ! fur!r application ( heat1 provid$ ! heat g5]at$ by ! process is suffici5t to br+ o!r p>ts ( ! sub/ance to ! k9dl+ temp]ature4 ,on ! o!r h&1 if ! heat g5]at$ is n suffici5t to ma9ta9 ! k9dl+ temp]ature1 combu/ion ceases4 ,oxides4 ,! comp\nds =m$ by ! oxidation ( any elem5t are call$ oxides4 ,?us 9 ! combu/ion ( sulphur1 phosphorus1 & iron1 ! comp\nds =m$ are call$ respectively oxide ( sulphur1 oxide ( phosphorus1 & oxide ( iron4 ,9 g5]al1 !n1 an oxide is a comp\nd ( oxyg5 ) ano!r elem5t4 ,a great _m sub/ances ( ?is class are kn[n2 9 fact1 ! oxides ( all ! common elem5ts h be5 prep>$1 ) ! exception ( ^? ( fluor9e & brom9e4 ,"s ( ^! are famili> comp\nds4 ,wat]1 = example1 is an oxide ( hydrog51 & lime an oxide ( ! metal calcium4 ,products ( combu/ion4 ,! p>ticul> oxides =m$ by ! combu/ion ( any sub/ance are call$ products ( combu/ion ( t sub/ance4 ,?us oxide ( sulphur is ! product ( ! combu/ion ( sulphur2 oxide ( iron is ! product ( ! combu/ion ( iron4 ,x is evid5t t ! products ( ! combu/ion ( any sub/ance mu/ weigh m ?an ! orig9al sub/ance1 ! increase 9 weight correspond+ to ! am\nt ( oxyg5 tak5 up 9 ! act ( combu/ion4 ,= example1 :5 iron burns ! oxide ( iron =m$ weighs m ?an ! orig9al iron4 ,9 "s cases ! products ( combu/ion are invisible gases1 s t ! sub/ance und]go+ combu/ion is app>5tly de/roy$4 ,?us1 :5 a c&le burns x is consum$1 & s f> z ! eye c judge no?+ is =m$ dur+ combu/ion4 ,t invisible gases are =m$1 h[ev]1 & t ! weight ( ^! is great] ?an ! weight ( ! c&le may be %[n by ! foll[+ exp]im5t4 ,illu/ration3 ,fig4 #g ,a lamp *imney is fill$ ) /icks ( ! comp\nd kn[n z sodium hydroxide 7cau/ic soda71 & susp5d$ f ! beam ( ! balance1 z %[n 9 ,fig4 #g4 ,a piece ( c&le is plac$ on ! balance pan s t ! wick comes j bel[ ! *imney1 & ! balance is br\ght to a level by add+ weights to ! o!r pan4 ,! c&le is !n light$4 ,! products =m$ pass up ?r\gh ! *imney & are absorb$ by ! sodium hydroxide4 ,al?\gh ! c&le burns away1 ! pan ^u :i* x re/s sl[ly s9ks1 %[+ t ! combu/ion is att5d$ by an increase 9 weight4 ,combu/ion 9 air & 9 oxyg54 ,combu/ion 9 air & 9 oxyg5 diff]s only 9 rapidity1 ! products =m$ be+ exactly ! same4 ,t ! process %\ld take place less rapidly 9 ! =m] is readily und]/ood1 = ! air is only ab\t "o fif? oxyg51 ! rema9+ f\r fif?s be+ in]t gases4 ,n only is less oxyg5 available1 b mu* ( ! heat is absorb$ 9 rais+ ! temp]ature ( ! in]t gases surr\nd+ ! sub/ance und]go+ combu/ion1 & ! temp]ature rea*$ 9 ! combu/ion is !re=e less4 ,phlogi/on !ory ( combu/ion4 ,! ,fr5* *emi/ ,lavoisi] 7#agdc-agid71 :o gave to oxyg5 its "n 0 ! fir/ to %[ t combu/ion is due to union ) oxyg54 ,previ\s to 8 "t combu/ion 0 suppos$ to be due to ! pres5ce ( a sub/ance or pr9ciple call$ phlogi/on4 ,"o sub/ance 0 ?\ght to be m combu/ible ?an ano!r because x conta9$ m phlogi/on4 ,coal1 = example1 0 ?\ght to be v ri* 9 phlogi/on4 ,! a%es left aft] combu/ion w\ld n burn because all ! phlogi/on _h escap$4 ,if ! phlogi/on c\ld be re/or$ 9 any way1 ! sub/ance w\ld !n become combu/ible aga94 ,al?\gh ?is view seems absurd to u 9 ! light ( our pres5t k1 x =m]ly _h g5]al acceptance4 ,! discov]y ( oxyg5 l$ ,lavoisi] to inve/igate ! subject1 & ?r\gh 8 exp]im5ts he arriv$ at ! true explanation ( combu/ion4 ,! discov]y ( oxyg5 toge!r ) ! "p x plays 9 combu/ion is g5]ally reg>d$ z ! mo/ important discov]y 9 ! hi/ory ( *emi/ry4 ,x m>k$ ! dawn ( a new p]iod 9 ! gr[? ( ! sci5ce4 ,combu/ion 9 ! broad s5se4 ,accord+ to ! def9ition giv5 above1 ! pres5ce ( oxyg5 is necess>y = combu/ion4 ,! t]m is sometimes us$1 h[ev]1 9 a broad] s5se to designate any *emical *ange att5d$ by ! evolution ( heat & light4 ,?us iron & sulphur1 or hydrog5 & *lor9e "u c]ta9 conditions1 w comb9e s rapidly t light is evolv$1 & ! action is call$ a combu/ion4 ,:5ev] combu/ion takes place 9 ! air1 h[ev]1 ! process is "o ( oxidation4 ,spontane\s combu/ion4 ,! temp]ature rea*$ 9 a giv5 *emical action1 su* z oxidation1 dep5ds ^u ! rate at :i* ! reaction takes place4 ,?is rate is usually increas$ by rais+ ! temp]ature ( ! sub/ances tak+ "p 9 ! action4 ,:5 a sl[ oxidation takes place "u su* conditions t ! heat g5]at$ is n lo/ by be+ conduct$ away1 ! temp]ature ( ! sub/ance und]go+ oxidation is rais$1 & ?is 9 turn ha/5s ! rate ( oxidation4 ,! rise 9 temp]ature may cont9ue 9 ?is way until ! k9dl+ temp]ature ( ! sub/ance is rea*$1 :5 combu/ion beg9s4 ,combu/ion occurr+ 9 ?is way is call$ spontane\s combu/ion4 ,c]ta9 oils1 su* z ! l9se$ oil us$ 9 pa9ts1 sl[ly und]go oxidation at ord9>y temp]atures1 & n infrequ5tly ! orig9 ( fires has be5 trac$ to ! spontane\s combu/ion ( oily rags4 ,! spontane\s combu/ion ( hay has be5 kn[n to set b>ns on fire4 ,heaps ( coal h be5 f\nd to be on fire :5 spontane\s combu/ion (f]$ ! only possible explanation4 ,importance ( oxyg54 #a4 ,oxyg5 is ess5tial to life4 ,among liv+ organisms only c]ta9 m9ute =ms ( plant life c exi/ )\t x4 ,9 ! process ( respiration ! air is tak5 into ! lungs :]e a c]ta9 am\nt ( oxyg5 is absorb$ by ! blood4 ,x is !n c>ri$ to all p>ts ( ! body1 oxidiz+ ! worn-out tissues & *ang+ !m into sub/ances :i* may readily be elim9at$ f ! body4 ,! heat g5]at$ by ?is oxidation is ! s\rce ( ! heat ( ! body4 ,! small am\nt ( oxyg5 :i* wat] dissolves f ! air supports all ! v>i$ =ms ( aquatic animals4 #b4 ,oxyg5 is also ess5tial to decay4 ,! process ( decay is really a k9d ( oxidation1 b x w only take place 9 ! pres5ce ( c]ta9 m9ute =ms ( life kn[n z bact]ia4 ,j h[ ^! assi/ 9 ! oxidation is n kn[n4 ,by ?is process ! dead products ( animal & vegetable life :i* collect on ! surface ( ! e>? are sl[ly oxidiz$ & s conv]t$ into h>mless sub/ances4 ,9 ?is way oxyg5 acts z a great purify+ ag5t4 #c4 ,oxyg5 is also us$ 9 ! treatm5t ( c]ta9 diseases 9 :i* ! pati5t is unable to inhale suffici5t air to supply ! necess>y am\nt ( oxyg54 ,,ozone ,prep>ation4 ,:5 electric sp>ks are pass$ ?r\gh oxyg5 or air a small p]c5tage ( ! oxyg5 is conv]t$ into a sub/ance call$ ozone1 :i* diff]s greatly f oxyg5 9 its prop]ties4 ,! same *ange c also be br\ght ab\t by c]ta9 *emical processes4 ,?us1 if "s pieces ( phosphorus are plac$ 9 a bottle & p>tially cov]$ ) wat]1 ! pres5ce ( ozone may soon be detect$ 9 ! air conta9$ 9 ! bottle4 ,! conv]sion ( oxyg5 into ozone is att5d$ by a *ange 9 volume1 #c volumes ( oxyg5 =m+ #b volumes ( ozone4 ,if ! result+ ozone is heat$ to ab\t #cjj1 ! rev]se *ange takes place1 ! #b volumes ( ozone be+ *ang$ back into #c volumes ( oxyg54 ,x is possible t traces ( ozone exi/ 9 ! atmosph]e1 al?\gh its pres5ce !re has n be5 def9itely prov$1 ! te/s =m]ly us$ = its detection hav+ be5 %[n to be unreliable4 ,prop]ties4 ,z commonly prep>$1 ozone is mix$ ) a l>ge excess ( oxyg54 ,x is possible1 h[ev]1 to sep>ate ! ozone & ?us obta9 x 9 pure =m4 ,! gas s obta9$ has ! *>act]i/ic odor notic$ ab\t electrical ma*9es :5 9 op]ation4 ,by subject+ x to great pressure & a l[ temp]ature1 ! gas cond5ses to a blui% liquid1 boil+ at -#aai4 ,:5 unmix$ ) o!r gases ozone is v explosive1 *ang+ back into oxyg5 ) ! lib]ation ( heat4 ,its *emical prop]ties are simil> to ^? ( oxyg5 except t x is f> m active4 ,air or oxyg5 conta9+ a small am\nt ( ozone is n[ us$ 9 place ( oxyg5 9 c]ta9 manufactur+ processes4 ,! diff]5ce betwe5 oxyg5 & ozone4 ,exp]im5ts %[ t 9 *ang+ oxyg5 into ozone no o!r k9d ( matt] is ei!r add$ to ! oxyg5 or )drawn f x4 ,! "q arises !n1 ,h[ c we acc\nt = ! diff]5ce 9 _! prop]ties8 ,x mu/ be rememb]$ t 9 all *anges we h to take into acc\nt en]gy z well z matt]4 ,by *ang+ ! am\nt ( en]gy 9 a sub/ance we *ange its prop]ties4 ,t oxyg5 & ozone conta9 diff]5t am\nts ( en]gy may be %[n 9 a numb] ( ways2 = example1 by ! fact t ! conv]sion ( ozone into oxyg5 is att5d$ by ! lib]ation ( heat4 ,! passage ( ! electric sp>ks ?r\gh oxyg5 has 9 "s way *ang$ ! en]gy cont5t ( ! elem5t & ?us x has acquir$ new prop]ties4 ,oxyg5 & ozone mu/1 !re=e1 be reg>d$ z id5tical s f> z ! k9d ( matt] ( :i* !y are compos$ is conc]n$4 ,_! diff]5t prop]ties are due to _! diff]5t en]gy cont5ts4 ,allotropic /ates or =ms ( matt]4 ,o!r elem5ts besides oxyg5 may exi/ 9 m ?an "o =m4 ,^! diff]5t =ms ( ! same elem5t are call$ allotropic /ates or =ms ( ! elem5t4 ,^! =ms diff] n only 9 physical prop]ties b also 9 _! en]gy cont5ts4 ,elem5ts (t5 exi/ 9 a v>iety ( =ms :i* look q diff]5t4 ,^! diff]5ces may be due to accid5tal causes1 su* z ! size or %ape ( ! p>ticles or ! way 9 :i* ! elem5t 0 prep>$4 ,only su* =ms1 h[ev]1 z h diff]5t en]gy cont5ts are prop]ly call$ allotropic =ms4 ,,measurem5t ,,( ,,gas ,,volumes ,/&>d conditions4 ,x is a well-kn[n fact t ! volume occupi$ by a def9ite weight ( any gas c be alt]$ by *ang+ ! temp]ature ( ! gas or ! pressure to :i* x is subject$4 ,9 measur+ ! volume ( gases x is !re=e necess>y1 = ! sake ( accuracy1 to adopt "s /&>d conditions ( temp]ature & pressure4 ,! conditions agre$ ^u are 7#a7 a temp]ature ( #j1 & 7#b7 a pressure equal to ! av]age pressure ex]t$ by ! atmosph]e at ! sea level1 t is1 #ajcc4c g4 p] squ>e c5timet]4 ,^! conditions ( temp]ature & pressure are kn[n z ! /&>d conditions1 & :5 ! volume ( a gas is giv5 x is und]/ood t ! measurem5t 0 made "u ^! conditions1 unless x is expressly /at$ o!rwise4 ,= example1 ! weight ( a lit] ( oxyg5 has be5 giv5 z #a4dbhe g4 ,?is means t "o lit] ( oxyg51 measur$ at a temp]ature ( #j & "u a pressure ( #ajcc4c g4 p] squ>e c5timet]1 weighs #a4dbhe g4 ,! conditions :i* prevail 9 ! laboratory are nev] ! /&>d conditions4 ,x becomes necess>y1 !re=e1 to f9d a way to calculate ! volume :i* a gas w occupy "u /&>d conditions f ! volume :i* x occupies "u any o!r conditions4 ,?is may be done 9 accordance ) ! foll[+ laws4 ,law ( ,*>les4 ,?is law expresses ! effect :i* a *ange 9 ! temp]ature ( a gas has ^u its volume4 ,x may be /at$ z foll[s3 ,= e degree ! temp]ature ( a gas rises above z]o ! volume ( ! gas is increas$ by #a_/bgc ( ! volume :i* x occupies at z]o2 likewise = e degree ! temp]ature ( ! gas falls bel[ z]o ! volume ( ! gas is decreas$ by #a_/bgc ( ! volume :i* x occupies at z]o1 provid$ 9 bo? cases t ! pressure to :i* ! gas is subject$ rema9s con/ant4 ,if ,v repres5ts ! volume ( gas at #j1 !n ! volume at #a w be ,v #a_/bgc ,v2 at #b x w be ,v #b_/bgc ,v2 or1 9 g5]al1 ! volume v1 at ! temp]ature t1 w be express$ by ! =mula 7#a7 v ,v t_/#bgc ,v1 or 7#b7 v ,v7#a 7t_/#bgc774 ,s9ce #a_/bgc #j4jjcff1 ! =mula may be writt5 7#c7 v ,v7#a #j4jjcfft74 ,s9ce ! value ( ,v 7volume "u /&>d conditions7 is ! "o usually s\ght1 x is conv5i5t to transpose ! equation to ! foll[+ =m3 7#d7 ,v v_/7#a #j4jjcfft74 ,! foll[+ problem w s]ve z an illu/ration ( ! application ( ?is equation4 ,! volume ( a gas at #bj is #gej cc42 f9d ! volume x w occupy at #j1 ! pressure rema9+ con/ant4 ,9 ?is case1 v #gej cc4 & t #bj4 ,by sub/itut+ ^! values1 equation 7#d7 becomes ,v #gej_/7a #j4jjcff #bj7 #fih4i cc4 ,law ( ,boyle4 ,?is law expresses ! relation betwe5 ! volume occupi$ by a gas & ! pressure to :i* x is subject$4 ,x may be /at$ z foll[s3 ,! volume ( a gas is inv]sely proportional to ! pressure "u :i* x is measur$1 provid$ ! temp]ature ( ! gas rema9s con/ant4 ,if ,v repres5ts ! volume :5 subject$ to a pressure ,p & v repres5ts its volume :5 ! pressure is *ang$ to p1 !n1 9 accordance ) ! above law1 ,v 3 v 33 p 3 ,p1 or ,,vp vp4 ,9 o!r words1 = a giv5 weight ( a gas ! product ( ! numb]s repres5t+ its volume & ! pressure to :i* x is subject$ is a con/ant4 ,s9ce ! pressure ( ! atmosph]e at any po9t is indicat$ by ! b>ometric read+1 x is conv5i5t 9 ! solution ( ! problems to sub/itute ! latt] = ! pressure measur$ 9 grams p] squ>e c5timet]4 ,! av]age read+ ( ! b>omet] at ! sea level is #gfj mm41 :i* corresponds to a pressure ( #ajcc4c g4 p] squ>e c5timet]4 ,! foll[+ problem w s]ve z an illu/ration ( ! application ( ,boyle's law4 ,a gas occupies a volume ( #ejj cc4 9 a laboratory :]e ! b>ometric read+ is #gdj mm4 ,:at volume w\ld x occupy if ! atmosph]ic pressure *ang$ s t ! read+ became #gej mm48 ,sub/itut+ ! values 9 ! equation ,,vp vp1 we h #ejj #gdj v #gej1 or v #dic4c cc4 ,v>iations 9 ! volume ( a gas due to *anges bo? 9 temp]ature & pressure4 ,inasmu* z corrections mu/ be made z a rule = bo? temp]ature & pressure1 x is conv5i5t to comb9e ! equations giv5 above = ! corrections = ea*1 s t ! two corrections may be made 9 "o op]ation4 ,! foll[+ equation is ?us obta9$3 7#e7 ,vs vp_/7#gfj7a #j4jjcfft771 9 :i* ,vs repres5ts ! volume ( a gas "u /&>d conditions & v1 p1 & t ! volume1 pressure1 & temp]ature respectively at :i* ! gas 0 actually measur$4 ,! foll[+ problem w s]ve to illu/rate ! application ( ?is equation4 ,a gas hav+ a temp]ature ( #bj occupies a volume ( #ejj cc4 :5 subject$ to a pressure indicat$ by a b>ometric read+ ( #gdj mm4 ,:at volume w\ld ?is gas occupy "u /&>d conditions8 ,9 ?is problem v #ejj1 p #gdj1 & t #bj4 ,sub/itut+ ^! values 9 ! above equation1 we get ,vs 7#ejj #gdj7_/7gfj 7#a #j4jjcff #bj77 #dec4f cc4 ,illu/ration3 ,fig4 #h ,v>iations 9 ! volume ( a gas due to ! pressure ( aque\s vapor4 ,9 _m cases gases are collect$ ov] wat]1 z expla9$ "u ! prep>ation ( oxyg54 ,9 su* cases !re is pres5t 9 ! gas a c]ta9 am\nt ( wat] vapor4 ,?is vapor ex]ts a def9ite pressure1 :i* acts 9 opposition to ! atmosph]ic pressure & :i* !re=e mu/ be subtract$ f ! latt] 9 det]m9+ ! effective pressure ^u ! gas4 ,?us1 suppose we wi% to det]m9e ! pressure to :i* ! gas 9 tube ,a 7,fig4 #h7 is subject$4 ,! tube is rais$ or l[]$ until ! level ( ! wat] inside & outside ! tube is ! same4 ,! atmosph]e presses d[n ^u ! surface ( ! wat] 7z indicat$ by ! arr[s71 ?us =c+ ! wat] upw>d )9 ! tube ) a pressure equal to ! atmosph]ic pressure4 ,! full =ce ( ?is upw>d pressure1 h[ev]1 is n sp5t 9 compress+ ! gas )9 ! tube1 = s9ce x is collect$ ov] wat] x conta9s a c]ta9 am\nt ( wat] vapor4 ,?is wat] vapor ex]ts a pressure 7z indicat$ by ! arr[ )9 ! tube7 9 opposition to ! upw>d pressure4 ,x is pla91 !re=e1 t ! effective pressure ^u ! gas is equal to ! atmosph]ic pressure less ! pressure ex]t$ by ! aque\s vapor4 ,! pressure ex]t$ by ! aque\s vapor increases ) ! temp]ature4 ,! figures repres5t+ ! ext5t ( ?is pressure 7(t5 call$ ! t5sion ( aque\s vapor7 are giv5 9 ! ,app5dix4 ,!y express ! pressure or t5sion 9 millimet]s ( m]cury1 j z ! atmosph]ic pressure is express$ 9 millimet]s ( m]cury4 ,repres5t+ ! pressure ( ! aque\s vapor by a1 =mula 7#e7 becomes 7#f7 ,vs v7p - a7_/7#gfj7a #j4jjcfft774 ,! foll[+ problem w s]ve to illu/rate ! me?od ( apply+ ! correction = ! pressure ( ! aque\s vapor4 ,! volume ( a gas measur$ ov] wat] 9 a laboratory :]e ! temp]ature is #bj & ! b>ometric read+ is #gdj mm4 is #ejj cc4 ,:at volume w\ld ?is occupy "u /&>d conditions8 ,! pressure ex]t$ by ! aque\s vapor at #bj 7see table 9 ,app5dix7 is equal to ! pressure ex]t$ by a column ( m]cury #ag4d mm4 9 height4 ,sub/itut+ ! values ( v1 t1 p1 & a 9 =mula 7#f71 we h 7#f7 ,vs #ejj7gdj - #ag4d7_/7gfj7a #j4jjcff #bj77 #ddb4i cc4 ,adju/m5t ( tubes be=e read+ gas volumes4 ,9 measur+ ! volumes ( gases collect$ 9 graduat$ tubes or o!r receiv]s1 ov] a liquid z illu/rat$ 9 ,fig4 #h1 ! read+ %\ld be tak5 aft] rais+ or l[]+ ! tube conta9+ ! gas until ! level ( ! liquid inside & outside ! tube is ! same2 = x is only "u ^! conditions t ! upw>d pressure )9 ! tube is ! same z ! atmosph]ic pressure4 ,,ex]cises #a4 ,:at is ! mean+ ( ! foll[+ words8 phlogi/on1 ozone1 phosphorus4 7,consult diction>y47 #b4 ,c combu/ion take place )\t ! emission ( light8 #c4 ,is ! evolution ( light always produc$ by combu/ion8 #d4 7a7 ,:at weight ( oxyg5 c be obta9$ f #ajj g4 ( wat]8 7b7 ,:at volume w\ld ?is occupy "u /&>d conditions8 #e4 7a7 ,:at weight ( oxyg5 c be obta9$ f #ejj;g4 ( m]curic oxide8 7b7 ,:at volume w\ld ?is occupy "u /&>d conditions8 #f4 ,:at weight ( ea* ( ! foll[+ comp\nds is necess>y to prep>e #ej l4 ( oxyg58 7a7 wat]2 7b7 m]curic oxide2 7c7 potassium *lorate4 #g4 ,r$uce ! foll[+ volumes to #j1 ! pressure rema9+ con/ant3 7a7 #aej cc4 at #aj2 7b7 #hdj cc4 at #bgc4 #h4 ,a c]ta9 volume ( gas is measur$ :5 ! temp]ature is #bj4 ,at :at temp]ature w its volume be d\bl$8 #i4 ,r$uce ! foll[+ volumes to /&>d conditions ( pressure1 ! temp]ature rema9+ con/ant3 7a7 #bjj cc4 at #gdj mm42 7b7 #ejj l4 at #chj mm4 #aj4 ,:at is ! weight ( #a l4 ( oxyg5 :5 ! pressure is #gej mm4 & ! temp]ature #j8 #aa4 ,r$uce ! foll[+ volumes to /&>d conditions ( temp]ature & pressure3 7a7 #cdj cc4 at #ab & #gec mm2 7b7 #ejj cc4 at #ae & #gdj mm4 #ab4 ,:at weight ( potassium *lorate is necess>y to prep>e #bej l4 ( oxyg5 at #bj & #gej mm48 #ac4 ,assum+ ! co/ ( potassium *lorate & m]curic oxide to be respectively #j4ej & #a4ej p] kilogram1 calculate ! co/ ( mat]ials necess>y = ! prep>ation ( #ej l4 ( oxyg5 f ea* ( ! above comp\nds4 #ad4 #ajj g4 ( potassium *lorate & #be g4 ( manganese dioxide 7 heat$ 9 ! prep>ation ( oxyg54 ,:at products 7 left 9 ! flask1 & h[ mu* ( ea* 0 pres5t8 ,,*apt] ,,iii ,,hydrog5 ,hi/orical4 ,! elem5t hydrog5 0 fir/ cle>ly recogniz$ z a di/9ct sub/ance by ! ,engli% inve/igator ,cav5di%1 :o 9 #agff obta9$ x 9 a pure /ate1 & %[$ x to be diff]5t f ! o!r inflammable airs or gases :i* _h long be5 kn[n4 ,lavoisi] gave x ! "n hydrog51 signify+ wat] =m]1 s9ce x _h be5 f\nd to be a con/itu5t ( wat]4 ,occurr5ce4 ,9 ! free /ate hydrog5 is f\nd 9 ! atmosph]e1 b only 9 traces4 ,9 ! comb9$ /ate x is widely di/ribut$1 be+ a con/itu5t ( wat] z well z ( all liv+ organisms1 & ! products d]iv$ f !m1 su* z />* & sug>4 ,ab\t #aj ( ! human body is hydrog54 ,comb9$ ) c>bon1 x =ms ! sub/ances :i* con/itute petroleum & natural gas4 ,x is an int]e/+ fact t :ile hydrog5 9 ! free /ate occurs only 9 traces on ! e>?1 x occurs 9 enorm\s quantities 9 ! gase\s matt] surr\nd+ ! sun & c]ta9 o!r />s4 ,prep>ation f wat]4 ,hydrog5 c be prep>$ f wat] by sev]al me?ods1 ! mo/ important ( :i* are ! foll[+4 #a4 ,by ! electric curr5t4 ,z has be5 indicat$ 9 ! prep>ation ( oxyg51 wat] is easily sep>at$ into its con/itu5ts1 hydrog5 & oxyg51 by pass+ an electric curr5t ?r\gh x "u c]ta9 conditions4 #b4 ,by ! action ( c]ta9 metals4 ,:5 br\ght into contact ) c]ta9 metals "u appropriate conditions1 wat] gives up a portion or ! :ole ( its hydrog51 its place be+ tak5 by ! metal4 ,9 ! case ( a few ( ! metals ?is *ange occurs at ord9>y temp]atures4 ,?us1 if a bit ( sodium is ?r[n on wat]1 an action is se5 to take place at once1 suffici5t heat be+ g5]at$ to melt ! sodium1 :i* runs ab\t on ! surface ( ! wat]4 ,! *ange :i* takes place consi/s 9 ! displacem5t ( "o half ( ! hydrog5 ( ! wat] by ! sodium1 & may be repres5t$ z foll[s3 hydrog5 sodium sodium hydrog5 7wat]7 hydrog5 7sodium hydroxide7 hydrog5 oxyg5 oxyg5 ,! sodium hydroxide =m$ is a :ite solid :i* rema9s dissolv$ 9 ! undecompos$ wat]1 & may be obta9$ by evaporat+ ! solution to dryness4 ,! hydrog5 is evolv$ z a gas & may be collect$ by suitable app>atus4 ,o!r metals1 su* z magnesium & iron1 decompose wat] rapidly1 b only at high] temp]atures4 ,:5 /eam is pass$ ov] hot iron1 = example1 ! iron comb9es ) ! oxyg5 ( ! /eam1 ?us displac+ ! hydrog54 ,exp]im5ts %[ t ! *ange may be repres5t$ z foll[s3 hydrog5 iron hydrog5 7wat]7 iron 7iron oxide7 hydrog5 oxyg5 oxyg5 hydrog5 ,! iron oxide =m$ is a r$di%-black comp\nd1 id5tical ) t obta9$ by ! combu/ion ( iron 9 oxyg54 ,directions = prep>+ hydrog5 by ! action ( /eam on iron4 ,! app>atus us$ 9 ! prep>ation ( hydrog5 f iron & /eam is %[n 9 ,fig4 #i4 ,a porcela9 or iron tube ,b1 ab\t #ej cm4 9 l5g? & #b cm4 or #c cm4 9 diamet]1 is p>tially fill$ ) f9e iron wire or tacks & connect$ z %[n 9 ! figure4 ,! tube ,b is heat$1 sl[ly at fir/1 until ! iron is r$-hot4 ,/eam is !n conduct$ ?r\gh ! tube by boil+ ! wat] 9 ! flask ,a4 ,! hot iron comb9es ) ! oxyg5 9 ! /eam1 sett+ free ! hydrog51 :i* is collect$ ov] wat]4 ,! gas :i* fir/ passes ov] is mix$ ) ! air previ\sly conta9$ 9 ! flask & tube1 & is all[$ to escape1 s9ce a mixture ( hydrog5 ) oxyg5 or air explodes viol5tly :5 br\ght 9 contact ) a flame4 ,x is evid5t t ! flask ,a mu/ be disconnect$ f ! tube be=e ! heat is )drawn4 ,t ! gas obta9$ is diff]5t f air & oxyg5 may be %[n by hold+ a bottle ( x m\? d[nw>d & br++ a light$ spl9t into x4 ,! hydrog5 is ignit$ & burns ) an almo/ colorless flame4 ,illu/ration ,fig4 #i ,prep>ation f acids 7usual laboratory me?od74 ,:ile hydrog5 c be prep>$ f wat]1 ei!r by ! action ( ! electric curr5t or by ! action ( c]ta9 metals1 ^! me?ods are n economical & are !re=e b little us$4 ,9 ! laboratory hydrog5 is g5]ally prep>$ f comp\nds kn[n z acids1 all ( :i* conta9 hydrog54 ,:5 acids are br\ght 9 contact ) c]ta9 metals1 ! metals dissolve & set free ! hydrog5 ( ! acid4 ,al?\gh ?is reaction is a q g5]al "o1 x has be5 f\nd mo/ conv5i5t 9 prep>+ hydrog5 by ?is me?od to use ei!r z9c or iron z ! metal & ei!r hydro*loric or sulphuric acid z ! acid4 ,hydro*loric acid is a comp\nd consi/+ ( #b4gg hydrog5 & #ig4bc *lor9e1 :ile sulphuric acid consi/s ( #b4je hydrog51 #cb4gj sulphur1 & #fe4be oxyg54 ,! *anges :i* take place 9 ! prep>ation ( hydrog5 f z9c & sulphuric acid 7dilut$ ) wat]7 may be repres5t$ z foll[s3 hydrog5 7sulphuric z9c 7z9c z9c sulphur acid7 sulphur sulphate7 hydrog5 oxyg5 oxyg5 ,9 o!r words1 ! z9c has tak5 ! place ( ! hydrog5 9 sulphuric acid4 ,! result+ comp\nd conta9s z9c1 sulphur1 & oxyg51 & is kn[n z z9c sulphate4 ,?is rema9s dissolv$ 9 ! wat] pres5t 9 ! acid4 ,x may be obta9$ 9 ! =m ( a :ite solid by evaporat+ ! liquid left aft] ! metal has pass$ into solution4 ,:5 z9c & hydro*loric acid are us$ ! foll[+ *anges take place3 hydrog5 7hydro*loric z9c 7z9c z9c *lor9e acid7 *lor9e *loride7 hydrog5 ,:5 iron is us$ ! *anges :i* take place are exactly simil> to ^? j giv5 = z9c4 ,illu/ration ,fig4 #aj4 ,directions = prep>+ hydrog5 f acids4 ,! prep>ation ( hydrog5 f acids is c>ri$ out 9 ! laboratory z foll[s3 ,! metal is plac$ 9 a flask or wide-m\!d bottle ,a 7,fig4 #aj7 & ! acid is add$ sl[ly ?r\gh ! funnel tube ,b4 ,! metal dissolves 9 ! acid1 :ile ! hydrog5 :i* is lib]at$ escapes ?r\gh ! exit tube ,c & is collect$ ov] wat]4 ,x is evid5t t ! hydrog5 :i* passes ov] fir/ is mix$ ) ! air f ! bottle ,a4 ,h5ce c>e mu/ be tak5 n to br+ a flame ne> ! exit tube1 s9ce1 z has be5 /at$ previ\sly1 su* a mixture explodes ) great viol5ce :5 br\ght 9 contact ) a flame4 ,precautions4 ,bo? sulphuric acid & z9c1 if impure1 are likely to conta9 small am\nts ( ars5ic4 ,su* mat]ials %\ld n be us$ 9 prep>+ hydrog51 s9ce ! ars5ic pres5t comb9es ) a portion ( ! hydrog5 to =m a v poison\s gas kn[n z ars9e4 ,on ! o!r h&1 *emically pure sulphuric acid1 i4e4 sulphuric acid t is entirely free f impurities1 w n act ^u *emically pure z9c4 ,! reaction may be />t$1 h[ev]1 by ! addition ( a few drops ( a solution ( copp] sulphate or plat9um tetra*loride4 ,physical prop]ties4 ,hydrog5 is simil> to oxyg5 9 t x is a colorless1 ta/eless1 odorless gas4 ,x is *>act]iz$ by its extreme lightness1 be+ ! lighte/ ( all kn[n sub/ances4 ,"o lit] ( ! gas weighs only #j4jhihd g4 ,on comp>+ ?is weight ) t ( an equal volume ( oxyg51 viz41 #a4dbhe g41 ! latt] is f\nd to be #ae4hh times z heavy z hydrog54 ,simil>ly1 air is f\nd to be #ad4ch times z heavy z hydrog54 ,soap bubbles bl[n ) hydrog5 rapidly rise 9 ! air4 ,on acc\nt ( its lightness x is possible to p\r x upw>d f "o bottle into ano!r4 ,?us1 if ! bottle ,a 7,fig4 #aa7 is fill$ ) hydrog51 plac$ m\? d[nw>d by ! side ( bottle ,b1 fill$ ) air1 & is !n gradually inv]t$ "u ,b z indicat$ 9 ! figure1 ! hydrog5 w fl[ upw>d into bottle ,b1 displac+ ! air4 ,its pres5ce 9 bottle ,b may !n be %[n by br++ a light$ spl9t to ! m\? ( ! bottle1 :5 ! hydrog5 w be ignit$ by ! flame4 ,x is evid5t1 f ?is exp]im5t1 t 9 ord] to reta9 ! gas 9 an op5 bottle ! bottle mu/ be plac$ m\? d[nw>d4 ,illu/ration ,fig4 #aa ,hydrog5 is f> m difficult to liquefy ?an any o!r gas1 ) ! exception ( helium1 a r>e elem5t rec5tly f\nd to exi/ 9 ! atmosph]e4 ,! ,engli% sci5ti/ ,dew>1 h[ev]1 9 #ahih succe$$ n only 9 obta9+ hydrog5 9 liquid /ate b also z a solid4 ,liquid hydrog5 is colorless & has a d5sity ( only #j4jg4 ,its boil+ po9t "u atmosph]ic pressure is -#beb4 ,"u dim9i%$ pressure ! temp]ature has be5 r$uc$ to -#bfb4 ,! solubility ( hydrog5 9 wat] is v slight1 be+ /ill less ?an t ( oxyg54 ,pure hydrog5 produces no injuri\s results :5 inhal$4 ,( c\rse "o c\ld n live 9 an atmosph]e ( ! gas1 s9ce oxyg5 is ess5tial to respiration4 ,*emical prop]ties4 ,at ord9>y temp]atures hydrog5 is n an active elem5t4 ,a mixture ( hydrog5 & *lor9e1 h[ev]1 w comb9e ) explosive viol5ce at ord9>y temp]ature if expos$ to ! sunlight4 ,! union c be br\ght ab\t also by heat+4 ,! product =m$ 9 ei!r case is hydro*loric acid4 ,"u suitable conditions hydrog5 comb9es ) nitrog5 to =m ammonia1 & ) sulphur to =m ! f\l-smell+ gas1 hydrog5 sulphide4 ,! aff9ity ( hydrog5 = oxyg5 is s great t a mixture ( hydrog5 & oxyg5 or hydrog5 & air explodes ) great viol5ce :5 heat$ to ! k9dl+ temp]ature 7ab\t #fab74 ,nev]!less "u prop] conditions hydrog5 may be made to burn quietly 9 ei!r oxyg5 or air4 ,! result+ hydrog5 flame is almo/ colorless & is v hot4 ,! combu/ion ( ! hydrog5 is1 ( c\rse1 due to its union ) oxyg54 ,! product ( ! combu/ion is !re=e a comp\nd ( hydrog5 & oxyg54 ,t ?is comp\nd is wat] may be %[n easily by exp]im5t4 ,illu/ration ,fig4 #ab ,directions = burn+ hydrog5 9 air4 ,! combu/ion ( hydrog5 9 air may be c>ri$ out safely z foll[s3 ,! hydrog5 is g5]at$ 9 ! bottle ,a 7,fig4 #ab71 is dri$ by conduct+ x ?r\gh ! tube ,x1 fill$ ) "s sub/ance 7g5]ally calcium *loride7 :i* has a great attraction = moi/ure1 & escapes ?r\gh ! tube ,t1 ! end ( :i* is drawn out to a jet4 ,! hydrog5 fir/ lib]at$ mixes ) ! air conta9$ 9 ! g5]ator4 ,if a flame is br\ght ne> ! jet be=e ?is mixture has all escap$1 a viol5t & v dang]\s explosion results1 s9ce ! entire app>atus is fill$ ) ! explosive mixture4 ,on ! o!r h&1 if ! flame is n appli$ until all ! air has be5 expell$1 ! hydrog5 is ignit$ & burns quietly1 s9ce only ! small am\nt ( x :i* escapes f ! jet c come 9 contact ) ! oxyg5 ( ! air at any "o "t4 ,by hold+ a cold1 dry bell j> or bottle ov] ! flame1 9 ! mann] %[n 9 ! figure1 ! /eam =m$ by ! combu/ion ( ! hydrog5 is cond5s$1 ! wat] collect+ 9 drops on ! sides ( ! j>4 ,precautions4 ,9 ord] to avoid dang] x is absolutely necess>y to prove t ! hydrog5 is free f air be=e ignit+ x4 ,?is c be done by te/+ small am\nts ( ! escap+ gas4 ,a conv5i5t & safe me?od ( do+ ?is is to fill a te/ tube ) ! gas by inv]t+ x ov] ! jet4 ,! hydrog51 on acc\nt ( its lightness1 collects 9 ! tube1 displac+ ! air4 ,aft] hold+ x ov] ! jet = a few mom5ts 9 ord] t x may be fill$ ) ! gas1 ! tube is g5tly br\ght1 m\? d[nw>d1 to ! flame ( a burn] plac$ n ne>] ?an an arm's l5g? f ! jet4 ,if ! hydrog5 is mix$ ) air a slight explosion occurs1 b if pure x burns quietly 9 ! tube4 ,! op]ation is repeat$ until ! gas burns quietly1 :5 ! tube is quickly br\ght back ov] ! jet = an in/ant1 :]eby ! escap+ hydrog5 is ignit$ by ! flame 9 ! tube4 ,illu/ration4 ,fig4 #ac ,a mixture ( hydrog5 & oxyg5 is explosive4 ,t a mixture ( hydrog5 & air is explosive may be %[n safely z foll[s3 ,a cork ?r\gh :i* passes a %ort glass tube ab\t #a cm4 9 diamet] is fitt$ air-tight into ! tubule ( a bell j> ( #b l4 or #c l4 capacity4 7,a ?ick glass bottle ) bottom remov$ may be us$47 ,! tube is clos$ ) a small rubb] /opp] & ! bell j> fill$ ) hydrog51 ! gas be+ collect$ ov] wat]4 ,:5 entirely fill$ ) ! gas ! j> is remov$ f ! wat] & support$ by blocks ( wood 9 ord] to leave ! bottom ( ! j> op51 z %[n 9 ,fig4 #ac4 ,! /opp] is n[ remov$ f ! tube 9 ! cork1 & ! hydrog51 :i* on acc\nt ( its lightness escapes f ! tube1 is at once light$4 ,z ! hydrog5 escapes1 ! air fl[s 9 at ! bottom ( ! j> & mixes ) ! rema9+ portion ( ! hydrog51 s t a mixture ( ! two soon =ms1 & a l\d explosion results4 ,! explosion is n dang]\s1 s9ce ! bottom ( ! j> is op51 ?us leav+ room = ! expansion ( ! hot gas4 ,s9ce air is only "o fif? oxyg51 ! rema9d] be+ in]t gases1 x may readily be inf]r$ t a mixture ( hydrog5 ) pure oxyg5 w\ld be f> m explosive ?an a mixture ( hydrog5 ) air4 ,su* mixtures %\ld n be made except 9 small quantities & by exp]i5c$ work]s4 ,hydrog5 does n support combu/ion4 ,:ile hydrog5 is readily combu/ible1 x is n a support] ( combu/ion4 ,9 o!r words1 sub/ances w n burn 9 x4 ,?is may be %[n by br++ a light$ c&le support$ by a /iff wire into a bottle or cyl9d] ( ! pure gas1 z %[n 9 ,fig4 #ad4 ,! hydrog5 is ignit$ by ! flame ( ! c&le & burns at ! m\? ( ! bottle1 :]e x comes 9 contact ) ! oxyg5 9 ! air4 ,:5 ! c&le is ?ru/ up into ! gas1 its flame is ext+ui%$ on acc\nt ( ! abs5ce ( oxyg54 ,if sl[ly )drawn1 ! c&le is relight$ z x passes ?r\gh ! lay] ( burn+ hydrog54 ,illu/ration3 ,fig4 #ad ,illu/ration3 ,fig4 #ae ,r$uction4 ,on acc\nt ( its great aff9ity = oxyg51 hydrog5 has ! p[] ( ab/ract+ x f _m ( its comp\nds4 ,?us1 if a /ream ( hydrog51 dri$ by pass+ ?r\gh ! tube ,b 7,fig4 #ae71 fill$ ) calcium *loride1 is conduct$ ?r\gh ! tube ,c conta9+ "s copp] oxide1 heat$ to a mod]ate temp]ature1 ! hydrog5 ab/racts ! oxyg5 f ! copp] oxide4 ,! *ange may be repres5t$ z foll[s3 hydrog5 copp] hydrog5 oxyg57copp] oxide7 oxyg5 7wat]7 copp] ,! wat] =m$ collects 9 ! cold portions ( ! tube ,c ne> its end4 ,9 ?is exp]im5t ! copp] oxide is said to und]go r$uction4 ,r$uction may !re=e be def9$ z ! process ( )draw+ oxyg5 f a comp\nd4 ,relation ( r$uction to oxidation4 ,at ! same "t t ! copp] oxide is r$uc$ x is cle> t ! hydrog5 is oxidiz$1 = x comb9es ) ! oxyg5 giv5 up by ! copp] oxide4 ,! two processes are !re=e v closely relat$1 & x usually happ5s t :5 "o sub/ance is oxidiz$ "s o!r sub/ance is r$uc$4 ,t sub/ance :i* gives up its oxyg5 is call$ an oxidiz+ ag5t1 :ile ! sub/ance :i* unites ) ! oxyg5 is call$ a r$uc+ ag5t4 ,! oxyhydrog5 bl[pipe4 ,?is is a =m ( app>atus us$ = burn+ hydrog5 9 pure oxyg54 ,z has be5 previ\sly /at$1 ! flame produc$ by ! combu/ion ( hydrog5 9 ! air is v hot4 ,x is evid5t t if pure oxyg5 is sub/itut$ = air1 ! temp]ature rea*$ w be mu* high]1 s9ce !re are no in]t gases to absorb ! heat4 ,! oxyhydrog5 bl[pipe1 us$ to effect ?is comb9ation1 consi/s ( a small tube plac$ )9 a l>g] "o1 z %[n 9 ,fig4 #af4 ,illu/ration3 ,fig4 #af ,! hydrog51 /or$ "u pressure1 g5]ally 9 /eel cyl9d]s1 is fir/ pass$ ?r\gh ! out] tube & ignit$ at ! op5 end ( ! tube4 ,! oxyg5 f a simil> cyl9d] is !n conduct$ ?r\gh ! inn] tube1 & mixes ) ! hydrog5 at ! end ( ! tube4 ,9 ord] to produce ! maximum heat1 ! hydrog5 & oxyg5 mu/ be admitt$ to ! bl[pipe 9 ! exact proportion 9 :i* !y comb9e1 viz41 #b volumes ( hydrog5 to #a ( oxyg51 or by weight1 #a "p ( hydrog5 to #g4id p>ts ( oxyg54 ,! int5sity ( ! heat may be %[n by br++ into ! flame pieces ( metal su* z iron wire or z9c4 ,^! burn ) great brilliancy4 ,ev5 plat9um1 hav+ a melt+ po9t ( #aggi1 may be melt$ by ! heat ( ! flame4 ,:ile ! oxyhydrog5 flame is int5sely hot1 x is almo/ non-lum9\s4 ,if direct$ aga9/ "s infusible sub/ance l ord9>y lime 7calcium oxide71 ! heat is s int5se t ! lime becomes inc&esc5t & gl[s ) a brilliant light4 ,?is is sometimes us$ z a s\rce ( light1 "u ! "n ( ,drummond or lime light4 ,illu/ration3 ,fig4 #ag ,! bla/ lamp4 ,a simil> =m ( app>atus is commonly us$ 9 ! laboratory z a s\rce ( heat "u ! "n bla/ lamp 7,fig4 #ag74 ,?is diff]s f ! oxyhydrog5 bl[pipe only 9 ! size ( ! tubes4 ,9 place ( ! hydrog5 & oxyg5 ! m accessible coal gas & air are respectively us$4 ,! =m] is compos$ l>gely ( a mixture ( free hydrog5 & gase\s comp\nds ( c>bon & hydrog54 ,:ile ! temp]ature ( ! flame is n s high z t ( ! oxyhydrog5 bl[pipe1 x nev]!less suffices = mo/ *emical op]ations c>ri$ out 9 ! laboratory4 ,uses ( hydrog54 ,on acc\nt ( its co/1 hydrog5 is b little us$ = comm]cial purposes4 ,x is sometimes us$ z a mat]ial = ! inflation ( balloons1 b usually ! mu* *eap] coal gas is sub/itut$ = x4 ,ev5 hot air is (t5 us$ :5 ! duration ( asc5sion is v %ort4 ,x has be5 us$ also z a s\rce ( heat & light 9 ! oxyhydrog5 bl[pipe4 ,:]e ! electric curr5t is available1 h[ev]1 ?is =m ( app>atus has be5 displac$ almo/ entirely by ! electric light & electric furnace1 :i* are mu* m economical & m p[]ful s\rces ( light & heat4 ,,ex]cises #a4 ,w a def9ite weight ( iron decompose an unlimit$ weight ( /eam8 #b4 ,:y is oxyg5 pass$ ?r\gh ! inn] tube ( ! oxyhydrog5 bl[pipe r ?an ! out]8 #c4 ,9 ,fig4 #ad1 w ! flame rema9 at ! m\? ( ! tube8 #d4 ,f ,fig4 #ae1 sugge/ a way = det]m9+ exp]im5tally ! quantity ( wat] =m$ 9 ! reaction4 #e4 ,di/+ui% cle>ly betwe5 ! foll[+ t]ms3 oxidation1 r$uction1 combu/ion1 & k9dl+ temp]ature4 #f4 ,is oxidation always accompani$ by r$uction8 #g4 ,:at is ! s\rce ( heat 9 ! lime light8 ,:at is ! exact use ( lime 9 ?is in/rum5t8 #h4 ,9 ,fig4 #ab1 :y is x necess>y to dry ! hydrog5 by means ( ! calcium *loride 9 ! tube ,x8 #i4 ,at :at pressure w\ld ! weight ( #a l4 ( hydrog5 be equal to t ( oxyg5 "u /&>d conditions8 #aj4 7a7 ,:at weight ( hydrog5 c be obta9$ f #aej g4 ( sulphuric acid8 7b7 ,:at volume w\ld ?is occupy "u /&>d conditions8 7c7 ,! d5sity ( sulphuric acid is #a4hd4 ,:at volume w\ld ! #aej g4 ( ! acid occupy8 #aa4 ,h[ _m lit]s ( hydrog5 c be obta9$ f #ej cc4 ( sulphuric acid hav+ a d5sity ( #a4hd8 #ab4 ,suppose y wi% to fill five lit] bottles ) hydrog51 ! gas to be collect$ ov] wat] 9 y\r laboratory1 h[ _m cubic c5timet]s ( sulphuric acid w\ld be requir$8 ,,*apt] ,,iv ,,comp\nds ,,( ,,hydrog5 ,,& ,,oxyg52 ,,wat] ,,& ,,hydrog5 ,,dioxide ,,wat] ,hi/orical4 ,wat] 0 long reg>d$ z an elem5t4 ,9 #agha ,cav5di% %[$ t x is =m$ by ! union ( hydrog5 & oxyg54 ,be+ a believ] 9 ! phlogi/on !ory1 h[ev]1 he fail$ to int]pret 8 results correctly4 ,a few ye>s lat] ,lavoisi] repeat$ ,cav5di%'s exp]im5ts & %[$ t wat] mu/ be reg>d$ z a comp\nd ( hydrog5 & oxyg54 ,g5]al me?ods employ$ = ! det]m9ation ( ! composition ( a comp\nd4 ,! composition ( a comp\nd may be det]m9$ by ei!r ( two g5]al processes ^! are kn[n z analysis & syn!sis4 #a4 ,analysis is ! process ( decompos+ a comp\nd into its con/itu5ts & det]m9+ :at ^! con/itu5ts are4 ,! analysis is qualitative :5 x results 9 m]ely det]m9+ :at elem5ts compose ! comp\nd2 x is quantitative :5 ! exact p]c5tage ( ea* con/itu5t is det]m9$4 ,qualitative analysis mu/ !re=e prec$e quantitative analysis1 = x mu/ be kn[n :at elem5ts1 are 9 a comp\nd be=e a me?od c be devis$ = det]m9+ exactly h[ mu* ( ea* is pres5t4 #b4 ,syn!sis is ! process ( =m+ a comp\nd f its con/itu5t p>ts4 ,x is !re=e ! rev]se ( analysis4 ,l analysis1 x may be ei!r qualitative or quantitative4 ,application ( ^! me?ods to ! det]m9ation ( ! composition ( wat]4 ,! det]m9ation ( ! composition ( wat] is a matt] ( great int]e/ n only because ( ! importance ( ! comp\nd b also because ! me?ods employ$ illu/rate ! g5]al me?ods ( analysis & syn!sis4 ,me?ods bas$ on analysis4 ,! me?ods bas$ on analysis may be ei!r qualitative or quantitative 9 "*4 ,illu/ration3 ,fig4 #ah #a4 ,qualitative analysis4 ,z 0 /at$ 9 ! /udy ( oxyg51 wat] may be sep>at$ into its compon5t p>ts by means ( ! electric curr5t4 ,! =m ( app>atus ord9>ily us$ = effect+ ?is analysis is %[n 9 ,fig4 #ah4 ,a plat9um wire1 to ! end ( :i* is atta*$ a small piece ( plat9um foil 7ab\t #ae mm4 by #be mm471 is fus$ ?r\gh ea* ( ! tubes ,b & ,d1 z %[n 9 ! figure4 ,! /opcocks at ! ends ( ^! tubes are op5$ & wat]1 to :i* has be5 add$ ab\t "o t5? ( its volume ( sulphuric acid1 is p\r$ into ! tube ,a until ! side tubes ,b & ,d are completely fill$4 ,! /opcocks are !n clos$4 ,! plat9um wires ext5d+ into ! tubes ,b & ,d are n[ connect$ ) ! wires lead+ f two or ?ree di*romate cells jo9$ 9 s]ies4 ,! pieces ( plat9um foil )9 ! tubes ?us become ! electrodes1 & ! curr5t fl[s f "o to ! o!r ?r\gh ! acidulat$ wat]4 ,z soon z ! curr5t passes1 bubbles ( gas rise f ea* ( ! electrodes & collect 9 ! upp] "p ( ! tubes4 ,! gas ris+ f ! negative electrode is f\nd to be hydrog51 :ile t f ! positive electrode is oxyg54 ,x w be se5 t ! volume ( ! hydrog5 is approximately d\ble t ( ! oxyg54 ,oxyg5 is m soluble 9 wat] ?an hydrog51 & a v little ( x is also lo/ by be+ conv]t$ into ozone & o!r sub/ances4 ,x has be5 f\nd t :5 ! necess>y corrections are made = ! error due to ^! facts1 ! volume ( ! hydrog5 is exactly d\ble t ( ! oxyg54 ,fig4 #ai illu/rates a simpl] =m ( app>atus1 :i* may be us$ 9 place ( t %[n 9 ,fig4 #ah4 ,a glass or porcela9 di% is p>tially fill$ ) wat] to :i* has be5 add$ ! prop] am\nt ( acid4 ,two tubes fill$ ) ! same liquid are inv]t$ ov] ! electrodes4 ,! gases result+ f ! decomposition ( ! wat] collect 9 ! tubes4 ,illu/ration3 ,fig4 #ai #b4 ,quantitative analysis4 ,! analysis j describ$ is purely qualitative & simply %[s t wat] conta9s hydrog5 & oxyg54 ,x does n prove ! abs5ce ( o!r elem5ts2 inde$ x does n prove t ! hydrog5 & oxyg5 are pres5t 9 ! proportion 9 :i* !y are lib]at$ by ! electric curr5t4 ,! me?od may be made quantitative1 h[ev]1 by weigh+ ! wat] decompos$ & also ! hydrog5 & oxyg5 obta9$ 9 its decomposition4 ,if ! comb9$ weights ( ! hydrog5 & oxyg5 exactly equal ! weight ( ! wat] decompos$1 !n x w\ld be prov$ t ! wat] consi/s ( hydrog5 & oxyg5 9 ! proportion 9 :i* !y are lib]at$ by ! electric curr5t4 ,?is exp]im5t is difficult to c>ry out1 h[ev]1 s t ! m accurate me?ods bas$ on syn!sis are us$4 ,me?ods bas$ on syn!sis4 ,two /eps are necess>y to asc]ta9 ! exact composition ( wat] by syn!sis3 7#a7 to %[ by qualitative syn!sis t wat] is =m$ by ! union ( oxyg5 ) hydrog52 7#b7 to det]m9e by quantitative syn!sis 9 :at proportion ! two elem5ts unite to =m wat]4 ,! fact t wat] is =m$ by ! comb9ation ( oxyg5 ) hydrog5 0 prov$ 9 ! prec$+ *apt]4 ,! quantitative syn!sis may be made z foll[s3 ,illu/ration3 ,fig4 #bj ,! comb9ation ( ! two gases is br\ght ab\t 9 a tube call$ a eudiomet]4 ,?is is a graduat$ tube ab\t #fj cm4 long & #b cm4 wide1 clos$ at "o end 7,fig4 #bj74 ,ne> ! clos$ end two plat9um wires are fus$ ?r\gh ! glass1 ! ends ( ! wires )9 ! tube be+ sep>at$ by a space ( #b mm or #c mm4 ,! tube is entirely fill$ ) m]cury & inv]t$ 9 a vessel ( ! same liquid4 ,pure hydrog5 is pass$ into ! tube until x is ab\t "o f\r? fill$4 ,! volume ( ! gas is !n read (f on ! scale & r$uc$ to /&>d conditions4 ,approximately an equal volume ( pure oxyg5 is !n introduc$ & ! volume aga9 read (f & r$uc$ to /&>d conditions4 ,?is gives ! total volume ( ! two gases4 ,f ?is ! volume ( ! oxyg5 introduc$ may be det]m9$ by subtract+ f x ! volume ( ! hydrog54 ,! comb9ation ( ! two gases is n[ br\ght ab\t by connect+ ! two plat9um wires ) an induction coil & pass+ a sp>k f "o wire to ! o!r4 ,imm$iately a slight explosion occurs4 ,! m]cury 9 ! tube is at fir/ depress$ because ( ! expansion ( ! gases due to ! heat g5]at$1 b at once reb\nds1 tak+ ! place ( ! gases :i* h comb9$ to =m wat]4 ,! volume ( ! wat] 9 ! liquid /ate is s small t x may be disreg>d$ 9 ! calculations4 ,9 ord] t ! temp]ature ( ! residual gas & ! m]cury may become uni=m1 ! app>atus is all[$ to /& = a few m9utes4 ,! volume ( ! gas is !n read (f & r$uc$ to /&>d conditions1 s t x may be comp>$ ) ! volumes ( ! hydrog5 & oxyg5 orig9ally tak54 ,! residual gas is !n te/$ 9 ord] to asc]ta9 :e!r x is hydrog5 or oxyg51 exp]im5ts hav+ prov$ t x is nev] a mixture ( ! two4 ,f ! in=mation ?us obta9$ ! composition ( ! wat] may be calculat$4 ,?us1 suppose ! read+s 7 z foll[s3 ,volume ( hydrog5 tak5 #bj4c cc4 ,volume ( hydrog5 & oxyg5 #ch4g ,volume ( oxyg5 #ah4d ,volume ( gas left aft] comb9ation has tak5 place 7oxyg57 #h4c ,! #bj4c cc4 ( hydrog5 h comb9$ ) #ah4d cc4 m9us #h4c cc4 7or #aj4a cc47 ( oxyg52 or approximately #b volumes ( hydrog5 h comb9$ ) #a ( oxyg54 ,s9ce oxyg5 is #ae4hh times z heavy z hydrog51 ! proportion by weight 9 :i* ! two gases comb9e is #a "p ( hydrog5 to #g4id ( oxyg54 ,precaution4 ,if ! two gases are introduc$ into ! eudiomet] 9 ! exact proportions 9 :i* !y comb9e1 aft] ! comb9ation has tak5 place ! liquid w rise & completely fill ! tube4 ,"u ^! conditions1 h[ev]1 ! tube is v likely to be brok5 by ! sudd5 upw>d ru% ( ! liquid4 ,h5ce 9 p]=m+ ! exp]im5t c>e is tak5 to introduce an excess ( "o ( ! gases4 ,a m conv5i5t =m ( eudiomet]4 ,a =m ( eudiomet] 7,fig4 #ba7 diff]5t f t %[n on page #dc is sometimes us$ to avoid ! calculations necess>y 9 r$uc+ ! volumes ( ! gases to ! same conditions ( temp]ature & pressure 9 ord] to make comp>isons4 ,) ?is app>atus x is possible to take ! read+s ( ! volumes "u ! same conditions ( temp]ature & pressure1 & ?us comp>e !m directly4 ,! app>atus 7,fig4 #ba7 is fill$ ) m]cury & ! gases introduc$ into ! tube ,a4 ,! exp]im5t is c>ri$ out z 9 ! prec$+ "o1 except t be=e tak+ ! read+ ( ! gas volumes1 m]cury is ei!r add$ to ! tube ,b or )drawn f x by means ( ! /opcock ,c1 until x /&s at exactly ! same height 9 bo? tubes4 ,! gas inclos$ 9 tube ,a is !n "u atmosph]ic pressure2 & s9ce b a few m9utes are requir$ = p]=m+ ! exp]im5t1 ! conditions ( temp]ature & pressure may be reg>d$ z con/ant4 ,h5ce ! volumes ( ! hydrog5 & oxyg5 & ( ! residual gas may be read (f f ! tube & directly comp>$4 ,illu/ration3 ,fig4 #ba ,me?od us$ by ,b]zelius & ,dumas4 ,! me?od us$ by ^! inve/igators enables u to det]m9e directly ! proportion by weight 9 :i* ! hydrog5 & oxyg5 comb9e4 ,fig4 #bb illu/rates ! app>atus us$ 9 mak+ ?is det]m9ation4 ,b is a glass tube conta9+ copp] oxide4 ,c & ,d are glass tubes fill$ ) calcium *loride1 a sub/ance :i* has great aff9ity = wat]4 ,! tubes ,b & ,c1 includ+ _! cont5ts1 are c>efully weigh$1 & ! app>atus connect$ z %[n 9 ! figure4 ,a sl[ curr5t ( pure hydrog5 is !n pass$ ?r\gh ,a1 & t "p ( ! tube ,b :i* conta9s copp] oxide is c>efully heat$4 ,! hydrog5 comb9es ) ! oxyg5 pres5t 9 ! copp] oxide to =m wat]1 :i* is absorb$ by ! calcium *loride 9 tube ,c4 ,! calcium *loride 9 tube ,d prev5ts any moi/ure ent]+ tube ,c f ! air4 ,! op]ation is cont9u$ until an appreciable am\nt ( wat] has be5 =m$4 ,! tubes ,b & ,c are !n weigh$ once m4 ,! loss ( weight 9 ! tube ,b w exactly equal ! weight ( oxyg5 tak5 up f ! copp] oxide 9 ! =mation ( ! wat]4 ,! ga9 9 weight 9 ! tube ,c w exactly equal ! weight ( ! wat] =m$4 ,! diff]5ce 9 ^! weights w ( c\rse equal ! weight ( ! hydrog5 pres5t 9 ! wat] =m$4 ,illu/ration3 ,fig4 #bb ,dumas' results4 ,! above me?od = ! det]m9ation ( ! composition ( wat] 0 fir/ us$ by ,b]zelius 9 #ahbj4 ,! "w 0 repeat$ 9 #ahdc by ,dumas1 ! av]age ( ^: results is z foll[s3 ,weight ( wat] =m$ #bcf4cf g4 ,oxyg5 giv5 up by ! copp] oxide #baj4jd ------ ,weight ( hydrog5 pres5t 9 wat] #bf4cb ,accord+ to ?is exp]im5t ! ratio ( hydrog5 to oxyg5 9 wat] is !re=e #bf4cb to #baj4jd1 or z l to #g4ih ,morley's results4 ,! ,am]ican *emi/ ,morley has rec5tly det]m9$ ! composition ( wat]1 extreme precautions be+ tak5 to use pure mat]ials & to elim9ate all s\rces ( error4 ,! hydrog5 & oxyg5 :i* comb9$1 z well z ! wat] =m$1 7 all accurately weigh$4 ,accord+ to ,morley's results1 #a "p ( hydrog5 by weight comb9es ) #g4id p>ts ( oxyg5 to =m wat]4 ,comp>ison ( results obta9$4 ,f ! above discussions x is easy to see t x is by exp]im5t alone t ! composition ( a comp\nd c be det]m9$4 ,diff]5t me?ods may lead to slightly diff]5t results4 ,! m accurate ! me?od *os5 & ! great] ! skill ) :i* ! exp]im5t is c>ri$ out1 ! m accurate w be ! results4 ,x is g5]ally conc$$ by *emi/s t ! results obta9$ by ,morley 9 ref]5ce to ! composition ( wat] are ! mo/ accurate ones4 ,9 accordance ) ^! results1 !n1 wat] mu/ be reg>d$ z a comp\nd conta9+ hydrog5 & oxyg5 9 ! proportion ( #a "p by weight ( hydrog5 to #g4id p>ts by weight ( oxyg54 ,relation betwe5 ! volume ( aque\s vapor & ! volumes ( ! hydrog5 & oxyg5 :i* comb9e to =m x4 ,:5 ! quantitative syn!sis ( wat] is c>ri$ out 9 ! eudiomet] z describ$ above1 ! wat] vapor =m$ by ! union ( ! hydrog5 & oxyg5 at once cond5ses4 ,! volume ( ! result+ liquid is s small t x may be disreg>d$ 9 mak+ ! calculations4 ,if1 h[ev]1 ! exp]im5t is c>ri$ out at a temp]ature ( #ajj or above1 ! wat]-vapor =m$ is n cond5s$ & x ?us becomes possible to comp>e ! volume ( ! vapor ) ! volumes ( hydrog5 & oxyg5 :i* comb9$ to =m x4 ,?is c be accompli%$ by surr\nd+ ! arm ,a ( ! eudiomet] 7,fig4 #bc7 ) ! tube ,b ?r\gh :i* is pass$ ! vapor obta9$ by boil+ "s liquid :i* has a boil+ po9t above #ajj4 ,9 ?is way x has be5 prov$ t #b volumes ( hydrog5 & #a volume ( oxyg5 comb9e to =m exactly #b volumes ( wat] vapor1 ! volumes all be+ measur$ "u ! same conditions ( temp]ature & pressure4 ,x w be not$ t ! relation betwe5 ^! volumes may be express$ by :ole numb]s4 ,! significance ( ?is v important fact w be discuss$ 9 a subsequ5t *apt]4 ,illu/ration3 ,fig4 #bc ,occurr5ce ( wat]4 ,wat] n only cov]s ab\t ?ree f\r?s ( ! surface ( ! e>?1 & is pres5t 9 ! atmosph]e 9 ! =m ( moi/ure1 b x is also a common con/itu5t ( ! soil & rocks & ( almo/ e =m ( animal & vegetable organism4 ,! human body is ne>ly #gj wat]4 ,?is is d]iv$ n only f ! wat] :i* we dr9k b also f ! food :i* we eat1 mo/ ( :i* conta9s a l>ge p]c5tage ( wat]4 ,?us potatoes conta9 ab\t #gh ( wat]1 milk #he1 beef ov] #ej1 apples #hd1 tomatoes #id4 ,impurities 9 wat]4 ,*emically pure wat] conta9s only hydrog5 & oxyg54 ,su* a wat] nev] occurs 9 nature1 h[ev]1 = be+ a good solv5t1 x takes up c]ta9 sub/ances f ! rocks & soil ) :i* x comes 9 contact4 ,:5 su* wat]s are evaporat$ ^! sub/ances are deposit$ 9 ! =m ( a residue4 ,ev5 ra9 wat]1 :i* is ! pure/ =m occurr+ 9 nature1 conta9s du/ p>ticles & gases dissolv$ f ! atmosph]e4 ,! =eign matt] 9 wat] is ( two k9ds1 namely1 m9]al1 su* z common salt & lime/one1 & organic1 t is ! products ( animal & vegetable life4 ,m9]al matt] 9 wat]4 ,! am\nt & nature ( ! m9]al matt] pres5t 9 diff]5t wat]s v>y greatly1 dep5d+ on ! "* ( ! rocks & soil ) :i* ! wat]s come 9 contact4 ,! m common ( ! sub/ances pres5t are common salt & comp\nds ( calcium1 magnesium1 & iron4 ,"o lit] ( ! av]age riv] wat] conta9s ab\t #age mg4 ( m9]al matt]4 ,wat] f deep wells naturally conta9s m m9]al matt] ?an riv] wat]1 g5]ally two or ?ree times z mu*1 :ile sea wat] conta9s z mu* z #ce1jjj mg4 to ! lit]4 ,effect ( impurities on heal?4 ,! m9]al matt] 9 wat] does n1 save 9 v exceptional cases1 r5d] ! wat] injuri\s to ! human sy/em4 ,9 fact ! pres5ce ( a c]ta9 am\nt ( su* matt] is advantage\s1 supply+ ! m9]al con/itu5ts necess>y = ! =mation ( ! solid tissues ( ! body4 ,! pres5ce ( organic matt]1 on ! o!r h&1 mu/ always be reg>d$ ) suspicion4 ,?is organic matt] may consi/ n only ( ! products ( animal & vegetable life b also ( c]ta9 microscopic =ms ( liv+ organisms :i* are likely to accompany su* products4 ,contagi\s diseases are kn[n to be due to ! pres5ce 9 ! body ( m9ute liv+ organisms or g]ms4 ,ea* disease is caus$ by its own p>ticul> k9d ( g]m4 ,?r\gh sewage ^! g]ms may f9d _! way f p]sons afflict$ ) disease into ! wat] supply1 & x is pr9cipally ?r\gh ! dr9k+ wat] t c]ta9 ( ^! diseases1 especially typhoid fev]1 are spread4 ,x becomes ( great importance1 !re=e1 to be able to detect su* matt] :5 pres5t 9 dr9k+ wat] z well z to devise me?ods :]eby x c be remov$ or at lea/ r5d]$ h>mless4 ,analysis ( wat]4 ,! m9]al analysis ( a wat] is1 z ! "n sugge/s1 simply ! det]m9ation ( ! m9]al matt] pres5t4 ,sanit>y analysis1 on ! o!r h&1 is ! det]m9ation ( ! organic matt] pres5t4 ,! physical prop]ties ( a wat] give no conclusive evid5ce z to its purity1 s9ce a wat] may be unfit = dr9k+ purposes & yet be p]fectly cle> & odorless4 ,nei!r c any reliance be plac$ on ! simple me?ods (t5 giv5 = te/+ ! purity ( wat]4 ,only ! tra9$ *emi/ c c>ry out su* me?ods ( analysis z c be reli$ ^u4 ,illu/ration3 ,fig4 #bd ,purification ( wat]4 ,?ree g5]al me?ods are us$ = ! purification ( wat]1 namely1 di/illation1 filtration1 & boil+4 #a4 ,di/illation4 ,! mo/ effective way ( purify+ natural wat]s is by ! process ( di/illation4 ,?is consi/s 9 boil+ ! wat] & cond5s+ ! /eam4 ,fig4 #bd illu/rates ! process ( di/illation1 z commonly conduct$ 9 ! laboratory4 ,ord9>y wat] is p\r$ into ! flask ,a & boil$4 ,! /eam is conduct$ ?r\gh ! cond5s] ,b1 :i* consi/s ess5tially ( a n>r[ glass tube seal$ )9 a l>g] "o1 ! space betwe5 ! two be+ fill$ ) cold wat]1 :i* is admitt$ at ,c & escapes at ,d4 ,! inn] tube is ?us kept cool & ! /eam 9 pass+ ?r\gh x is cond5s$4 ,! wat] =m$ by ! cond5sation ( ! /eam collects 9 ! receiv] ,e & is kn[n z di/ill$ wat]4 ,su* wat] is practically pure1 s9ce ! impurities are nonvolatile & rema9 9 ! flask ,a4 ,comm]cial di/illation4 ,9 prep>+ di/ill$ wat] on a l>ge scale1 ! /eam is g5]at$ 9 a boil] or o!r metal conta9] & cond5s$ by pass+ x ?r\gh a pipe made ( metal1 g5]ally t94 ,?is pipe is w\nd into a spiral & is surr\nd$ by a curr5t ( cold wat]4 ,di/ill$ wat] is us$ by ! *emi/ 9 almo/ all ( 8 "w4 ,x is also us$ 9 ! manufacture ( artificial ice & = dr9k+ wat]4 ,fractional di/illation4 ,9 prep>+ di/ill$ wat]1 x is evid5t t if ! natural wat] conta9s "s sub/ance :i* is volatile its vapor w pass ov] & be cond5s$ ) ! /eam1 s t ! di/illate w n be pure wat]4 ,ev5 su* mixtures1 h[ev]1 may g5]ally be sep>at$ by repeat$ di/illation4 ,?us1 if a mixture ( wat] 7boil+ po9t #ajj7 & alcohol 7boil+ po9t #gh7 is di/ill$1 ! alcohol1 hav+ ! l[] boil+ po9t1 t5ds to di/ill fir/1 foll[$ by ! wat]4 ,! sep>ation ( ! two is n p]fect1 h[ev]1 b may be made ne>ly s by repeat$ di/illations4 ,! process ( sep>at+ a mixture ( volatile sub/ances by di/illation is kn[n z fractional di/illation4 #b4 ,filtration4 ,! process ( di/illation practically removes all nonvolatile =eign matt]1 m9]al z well z organic4 ,9 purify+ wat] = dr9k+ purposes1 h[ev]1 x is only necess>y to elim9ate ! latt] or to r5d] x h>mless4 ,?is is ord9>ily done ei!r by filtration or boil+4 ,9 filtration ! wat] is pass$ ?r\gh "s m$ium :i* w reta9 ! organic matt]4 ,ord9>y *>coal is a por\s sub/ance & w cond5se )9 its pores ! organic matt] 9 wat] if br\ght 9 contact ) x4 ,x is !re=e well adapt$ to ! con/ruction ( filt]s4 ,su* filt]s to be effective mu/ be kept clean1 s9ce x is evid5t t ! *>coal is useless aft] its pores are fill$4 ,a m effective type ( filt] is ! ,*amb]la9-,pa/eur filt]4 ,9 ?is ! wat] is =c$ ?r\gh a por\s cyl9drical cup1 ! pores be+ s m9ute z to /ra9 out ! organic matt]4 ,city filtration b$s4 ,= purify+ ! wat] supply ( cities1 l>ge filtration b$s are prep>$ f s& & gravel1 & ! wat] is all[$ to filt] ?r\gh ^!4 ,"s ( ! impurities are /ra9$ out by ! filt]1 :ile o!rs are decompos$ by ! action ( c]ta9 k9ds ( bact]ia pres5t 9 ! s&4 ,fig4 #be %[s a cross section ( a portion ( ! filt] us$ 9 purify+ ! wat] supply ( ,philadelphia4 ,! wat] filt]s ?r\gh ! s& & gravel & passes into ! por\s pipe ,a1 f :i* x is pump$ into ! city ma9s4 ,! filt]s are cov]$ to prev5t ! wat] f freez+ 9 cold wea!r4 ,illu/ration3 ,fig4 #be #c4 ,boil+4 ,a simpl] & equally effici5t me?od = purify+ wat] = dr9k+ purposes consi/s 9 boil+ ! wat]4 ,x is ! g]ms 9 wat] t r5d] x dang]\s to heal?4 ,^! g]ms are liv+ =ms ( matt]4 ,if ! wat] is boil$1 ! g]ms are kill$ & ! wat] r5d]$ safe4 ,:ile ^! g]ms are de/roy$ by heat1 cold has little effect ^u !m4 ,?us ,dew>1 9 work+ ) liquid hydrog51 expos$ "s ( ^! m9ute =ms ( life to ! temp]ature ( boil+ hydrog5 7-#beb7 )\t kill+ !m4 ,self-purification ( wat]4 ,x has long be5 kn[n t wat] contam9at$ ) organic matt] t5ds to purify itself :5 expos$ to ! air4 ,?is is due to ! fact t ! wat] takes up a small am\nt ( oxyg5 f ! air1 :i* gradually oxidizes ! organic matt] pres5t 9 ! wat]4 ,:ile wat] is und\bt$ly purifi$ 9 ?is way1 ! me?od _c be reli$ ^u to purify a contam9at$ wat] s z to r5d] x safe = dr9k+ purposes4 ,physical prop]ties4 ,pure wat] is an odorless & ta/eless liquid1 colorless 9 ?9 lay]s1 b hav+ a blui% t+e :5 obs]v$ ?r\gh a consid]able ?ickness4 ,x solidifies at #j & boils at #ajj "u ! normal pressure ( "o atmosph]e4 ,if ! pressure is increas$1 ! boil+ po9t is rais$4 ,:5 wat] is cool$ x /eadily contracts until ! temp]ature ( #d is rea*$3 x !n exp&s4 ,wat] is rem>kable = its ability to dissolve o!r sub/ances1 & is ! be/ solv5t kn[n4 ,solutions ( solids 9 wat] are m frequ5tly employ$ 9 *emical "w ?an are ! solid sub/ances1 = *emical action betwe5 sub/ances goes on m readily :5 !y are 9 solution ?an x does :5 !y are 9 ! solid /ate4 ,*emical prop]ties4 ,wat] is a v /able sub/ance1 or1 9 o!r words1 x does n und]go decomposition readily4 ,to decompose x into its elem5ts by heat alone requires a v high temp]ature2 at #bejj1 = example1 only ab\t #e ( ! entire am\nt is decompos$4 ,?\gh v /able t[>ds heat1 wat] c be decompos$ 9 o!r ways1 z by ! action ( ! electrical curr5t or by c]ta9 metals4 ,heat ( =mation & heat ( decomposition are equal4 ,! fact t a v high temp]ature is necess>y to decompose wat] into hydrog5 & oxyg5 is 9 accord ) ! fact t a great deal ( heat is evolv$ by ! union ( hydrog5 & oxyg52 = x has be5 prov$ t ! heat necess>y to decompose a comp\nd into its elem5ts 7heat ( decomposition7 is equal to ! heat evolv$ 9 ! =mation ( a comp\nd f its elem5ts 7heat ( =mation74 ,wat] ( cry/allization4 ,:5 a solid is dissolv$ 9 wat] & ! result+ solution is all[$ to evaporate1 ! solid sep>ates out1 (t5 9 ! =m ( cry/als4 ,x has be5 f\nd t ! cry/als ( _m comp\nds1 al?\gh p]fectly dry1 give up a def9ite am\nt ( wat] :5 heat$1 ! sub/ance at ! same "t los+ its cry/all9e =m4 ,su* wat] is call$ wat] ( cry/allization4 ,?is v>ies 9 am\nt ) diff]5t comp\nds1 b is p]fectly def9ite = ! same comp\nd4 ,?us1 if a p]fectly dry cry/al ( copp] sulphate is /rongly heat$ 9 a tube1 wat] is evolv$ & cond5ses on ! sides ( ! tube1 ! cry/al crumbl+ to a light p[d]4 ,! weight ( ! wat] evolv$ is always equal to exactly #cf4jg ( ! weight ( copp] sulphate cry/als heat$4 ,! wat] mu/ !re=e be 9 *emical comb9ation ) ! sub/ance compos+ ! cry/al2 = if simply mix$ ) x or adh]+ to x1 n only w\ld ! sub/ance appe> moi/ b ! am\nt pres5t w\ld und\bt$ly v>y4 ,! comb9ation1 h[ev]1 mu/ be a v weak "o1 s9ce ! wat] is (t5 expell$ by ev5 a g5tle heat4 ,inde$1 9 "s cases ! wat] is giv5 up on simple exposure to air4 ,su* comp\nds are said to be effloresc5t4 ,?us a cry/al ( sodium sulphate 7,glaub]'s salt7 on exposure to air crumbles to a f9e p[d]1 ow+ to ! escape ( its wat] ( cry/allization4 ,o!r sub/ances h j ! opposite prop]ty3 !y absorb moi/ure :5 expos$ to ! air4 ,= example1 if a bit ( dry calcium *loride is plac$ 9 moi/ air1 9 ! c\rse ( a few h\rs x w h absorb$ suffici5t moi/ure to dissolve x4 ,su* sub/ances are said to be deliquesc5t4 ,a deliquesc5t body s]ves z a good dry+ or desiccat+ ag5t4 ,we h already employ$ calcium *loride z an ag5t = absorb+ ! moi/ure f hydrog54 ,_m sub/ances1 z = example qu>tz1 =m cry/als :i* conta9 no wat] ( cry/allization4 ,me*anically inclos$ wat]4 ,wat] ( cry/allization mu/ be c>efully di/+ui%$ f wat] :i* is me*anically inclos$ 9 a cry/al & :i* c be remov$ by p[d]+ ! cry/al & dry+4 ,?us1 :5 cry/als ( common salt are heat$1 ! wat] inclos$ 9 ! cry/al is *ang$ into /eam & bur/s ! cry/al ) a crackl+ s\nd4 ,su* cry/als are said to decrepitate4 ,t ?is wat] is n comb9$ is prov$ by ! fact t ! am\nt pres5t v>ies & t x has all ! prop]ties ( wat]4 ,uses ( wat]4 ,! importance ( wat] 9 its relation to life & comm]ce is too well kn[n to require comm5t4 ,its importance to ! *emi/ has also be5 po9t$ out4 ,x rema9s to call att5tion to ! fact t x is us$ z a /&>d 9 _m physical measurem5ts4 ,?us #j & #ajj on ! c5tigrade scale are respectively ! freez+ & ! boil+ po9ts ( wat] "u normal pressure4 ,! weight ( #a cc4 ( wat] at its po9t ( greate/ d5sity is ! unit ( weight 9 ! metric sy/em1 namely1 ! gram4 ,x is also tak5 z ! unit = ! det]m9ation ( ! d5sity ( liquids & solids z well z = ! measurem5t ( am\nts ( heat4 ,,hydrog5 ,,dioxide ,composition4 ,z has be5 %[n1 #a "p by weight ( hydrog5 comb9es ) #g4id p>ts by weight ( oxyg5 to =m wat]4 ,x is possible1 h[ev]1 to obta9 a second comp\nd ( hydrog5 & oxyg5 diff]+ f wat] 9 composition 9 t #a "p by weight ( hydrog5 is comb9$ ) #b #g4id1 or #ae4hh p>ts1 ( oxyg54 ,?is comp\nd is call$ hydrog5 dioxide or hydrog5 p]oxide1 ! prefixes di- & p]- signify+ t x conta9s m oxyg5 ?an hydrog5 oxide1 :i* is ! *emical "n = wat]4 ,prep>ation4 ,hydrog5 dioxide _c be prep>$ *eaply by ! direct union ( hydrog5 & oxyg51 & indirect me?ods mu/ !re=e be us$4 ,x is commonly prep>$ by ! action ( a solution ( sulphuric acid on b>ium dioxide4 ,! *ange :i* takes place may be indicat$ z foll[s3 sulphuric acid b>ium dioxide b>ium sulphate hydrog5 dioxide -------------- -------------- --------------- ---------------- hydrog5 b>ium b>ium hydrog5 sulphur oxyg5 sulphur oxyg5 oxyg5 oxyg5 ,9 o!r words1 ! b>ium & hydrog5 9 ! two comp\nds ex*ange places4 ,by ?is me?od a dilute solution ( ! dioxide 9 wat] is obta9$4 ,x is possible to sep>ate ! dioxide f ! wat] by fractional di/illation4 ,?is is att5d$ ) great difficulties1 h[ev]1 s9ce ! pure dioxide is explosive4 ,! di/illation is c>ri$ on "u dim9i%$ pressure s z to l[] ! boil+ po9ts z mu* z possible2 o!rwise ! high temp]ature w\ld decompose ! dioxide4 ,prop]ties4 ,pure hydrog5 dioxide is a colorless sirupy liquid hav+ a d5sity ( #a4di4 ,its mo/ *>act]i/ic prop]ty is ! ease ) :i* x decomposes into wat] & oxyg54 ,"o "p by weight ( hydrog5 is capable ( hold+ firmly only #g4id p>ts ( oxyg54 ,! additional #g4id p>ts ( oxyg5 pres5t 9 hydrog5 dioxide are !re=e easily evolv$1 ! comp\nd break+ d[n into wat] & oxyg54 ,?is decomposition is att5d$ by ! g5]ation ( consid]able heat4 ,9 dilute solution hydrog5 dioxide is fairly /able1 al?\gh su* a solution %\ld be kept 9 a d>k1 cool place1 s9ce bo? heat & light aid 9 ! decomposition ( ! dioxide4 ,uses4 ,solutions ( hydrog5 dioxide are us$ l>gely z oxidiz+ ag5ts4 ,! solution sold by druggi/s conta9s #c ( ! dioxide & is us$ 9 m$ic9e z an antiseptic4 ,its use z an antiseptic dep5ds ^u its oxidiz+ prop]ties4 ,,ex]cises #a4 ,:y does ! *emi/ use di/ill$ wat] 9 mak+ solutions1 r ?an filt]$ wat]8 #b4 ,h[ c\ld y det]m9e ! total am\nt ( solid matt] dissolv$ 9 a sample ( wat]8 #c4 ,h[ c\ld y det]m9e :e!r a giv5 sample ( wat] is di/ill$ wat]8 #d4 ,h[ c\ld ! pres5ce ( air dissolv$ 9 wat] be detect$8 #e4 ,h[ c\ld ! am\nt ( wat] 9 a food su* z bread or potato be det]m9$8 #f4 ,w\ld ice froz5 f impure wat] necess>ily be free f disease g]ms8 #g4 ,suppose t ! maximum d5sity ( wat] 7 at #j 9 place ( #d2 :at effect w\ld ?is h on ! =mation ( ice on bodies ( wat]8 #h4 ,is x possible = a sub/ance to conta9 bo? me*anically inclos$ wat] & wat] ( cry/allization8 #i4 ,if /eam is heat$ to #bjjj & aga9 cool$1 has any *emical *ange tak5 place 9 ! /eam8 #aj4 ,:y is cold wat] pass$ into ,c in/ead ( ,d 7,fig4 #bd78 #aa4 ,m5tion at lea/ two advantages t a metal cond5s] has ov] a glass cond5s]4 #ab4 ,draw a diagram ( ! app>atus us$ 9 y\r laboratory = supply+ di/ill$ wat]4 #ac4 #bj cc4 ( hydrog5 & #g cc4 ( oxyg5 are plac$ 9 a eudiomet] & ! mixture explod$4 7a7 ,h[ _m cubic c5timet]s ( aque\s vapor are =m$8 7b7 ,:at gas & h[ mu* ( x rema9s 9 excess8 #ad4 7a7 ,:at weight ( wat] c be =m$ by ! combu/ion ( #ajj ,l ( hydrog51 measur$ "u /&>d conditions8 7b7,:at volume ( oxyg5 w\ld be requir$ 9 7a78 7c7,:at weight ( potassium *lorate is necess>y to prep>e ?is am\nt ( oxyg58 #ae4 ,:at weight ( oxyg5 is pres5t 9 #a kg4 ( ! ord9>y hydrog5 dioxide solution8 ,9 ! decomposition ( ?is weight ( ! dioxide into wat] & oxyg51 :at volume ( oxyg5 7measur$ "u /&>d conditions7 is evolv$8 ,,*apt] ,v ,,! ,,atomic ,,!ory ,?ree fundam5tal laws ( matt]4 ,be=e we c ga9 any v def9ite idea 9 reg>d to ! /ructure ( matt]1 & ! way 9 :i* diff]5t k9ds ( sub/ances act *emically ^u ea* o!r1 x is necess>y to h cle>ly 9 view ?ree fundam5tal laws ( matt]4 ,^! laws h be5 e/abli%$ by exp]im5t1 & any conception :i* may be =m$ conc]n+ matt] mu/ !re=e be 9 h>mony ) !m4 ,! laws are z foll[s3 ,law ( cons]vation ( matt]4 ,?is law has already be5 t\*$ ^u 9 ! introductory *apt]1 & ne$s no fur!r discussion4 ,x w be recall$ t x may be /at$ ?us3 ,matt] c nei!r be creat$ nor de/roy$1 ?\gh x c be *ang$ f "o =m into ano!r4 ,law ( def9ite composition4 ,9 ! e>li] days ( *emi/ry !re 0 mu* discussion z to :e!r ! composition ( a giv5 comp\nd is always precisely ! same or :e!r x is subject to "s v>iation4 ,two ,fr5*m51 ,b]?ollet & ,pr\/1 7 ! lead]s 9 ?is discussion1 & a great deal ( mo/ useful exp]im5t+ 0 done to decide ! "q4 ,_! exp]im5ts1 z well z all succe$+ ones1 h %[n t ! composition ( a pure *emical comp\nd is always exactly ! same4 ,wat] obta9$ by melt+ pure ice1 cond5s+ /eam1 burn+ hydrog5 9 oxyg51 has always #aa4ah hydrog5 & #hh4hb oxyg5 9 x4 ,r$ oxide ( m]cury1 f :atev] s\rce x is obta9$1 conta9s #ib4f m]cury & #g4d oxyg54 ,?is tru? is kn[n z ! law ( def9ite composition1 & may be /at$ ?us3 ,! composition ( a *emical comp\nd nev] v>ies4 ,law ( multiple proportion4 ,x has already be5 not$1 h[ev]1 t hydrog5 & oxyg5 comb9e 9 two diff]5t ratios to =m wat] & hydrog5 dioxide respectively4 ,x w be obs]v$ t ?is fact does n contradict ! law ( def9ite composition1 = entirely diff]5t sub/ances are =m$4 ,^! comp\nds diff] f ea* o!r 9 composition1 b ! composition ( ea* "o is always con/ant4 ,?is ability ( two elem5ts to unite 9 m ?an "o ratio is v frequ5tly obs]v$4 ,c>bon & oxyg5 comb9e 9 two diff]5t ratios2 nitrog5 & oxyg5 comb9e to =m z _m z five di/9ct comp\nds1 ea* ) its own precise composition4 ,9 ! fir/ decade ( ! la/ c5tury ,john ,dalton1 an ,engli% s*ool-tea*] & philosoph]1 endeavor$ to f9d "s rule :i* holds betwe5 ! ratios 9 :i* two giv5 sub/ances comb9e4 ,8 /udies br\ght to light a v simple relation1 :i* ! foll[+ examples w make cle>4 ,9 wat] ! hydrog5 & oxyg5 are comb9$ 9 ! ratio ( #a "p by weight ( hydrog5 to #g4id p>ts by weight ( oxyg54 ,9 hydrog5 dioxide ! #a "p by weight ( hydrog5 is comb9$ ) #ae4hh p>ts by weight ( oxyg54 ,! ratio betwe5 ! am\nts ( oxyg5 :i* comb9e ) ! same am\nt ( hydrog5 to =m wat] & hydrog5 dioxide respectively is !re=e #g4id3 #ae4hh1 or #a3 #b4 ,illu/ration3 ,,john ,,dalton 7,engli%7 7#agff-ahdd7 ,develop$ ! atomic !ory2 made _m /udies on ! prop]ties & ! composition ( gases4 ,8 book entitl$ ,a ,new ,sy/em ( ,*emical ,philosophy _h a l>ge influ5ce on ! developm5t ( *emi/ry ,simil>ly1 ! elem5t iron comb9es ) oxyg5 to =m two oxides1 "o ( :i* is black & ! o!r r$4 ,by analysis x has be5 %[n t ! =m] conta9s #a "p by weight ( iron comb9$ ) #j4bhf p>ts by weight ( oxyg51 :ile ! latt] conta9s #a "p by weight ( iron comb9$ ) #j4dbi p>ts by weight ( oxyg54 ,"h aga9 we f9d t ! am\nts ( oxyg5 :i* comb9e ) ! same fix$ am\nt ( iron to =m ! two comp\nds are 9 ! ratio ( small :ole numb]s1 viz41 #b3c4 ,_m o!r examples ( ?is simple relation might be giv51 s9ce x has be5 f\nd to hold true 9 all cases :]e m ?an "o comp\nd is1 =m$ f ! same elem5ts4 ,dalton's law ( multiple proportion /ates ^! facts z foll[s3 ,:5 any two elem5ts1 ,a & ,b1 comb9e to =m m ?an "o comp\nd1 ! am\nts ( ,b :i* unite ) any fix$ am\nt ( ,a be> ! ratio ( small :ole numb]s to ea* o!r4 ,hypo!sis necess>y to expla9 ! laws ( matt]4 ,^! ?ree g5]alizations are call$ laws1 because !y express 9 concise language tru?s :i* are f\nd by c>eful exp]im5t to hold good 9 all cases4 ,!y d n (f] any explanation ( ! facts1 b m]ely /ate !m4 ,! human m9d1 h[ev]1 does n re/ cont5t ) ! m]e b>e facts1 b seeks ev] to le>n ! explanation ( ! facts4 ,a sugge/ion :i* is (f]$ to expla9 su* a set ( facts is call$ an hypo!sis4 ,! sugge/ion :i* ,dalton (f]$ to expla9 ! ?ree laws ( matt]1 call$ ! atomic hypo!sis1 0 prompt$ by 8 view ( ! con/itution ( matt]1 & x involves ?ree di/9ct assumptions 9 reg>d to ! nature ( matt] & *emical action4 ,dalton c\ld n prove ^! assumptions to be true1 b he saw t if !y 7 true ! laws ( matt] become v easy to und]/&4 ,dalton's atomic hypo!sis4 ,! ?ree assumptions :i* ,dalton made 9 reg>d to ! nature ( matt]1 & :i* toge!r con/itute ! atomic hypo!sis1 are ^!3 #a4 ,all elem5ts are made up ( m9ute1 indep5d5t p>ticles :i* ,dalton designat$ z atoms4 #b4 ,all atoms ( ! same elem5t h equal masses2 ^? ( diff]5t elem5ts h diff]5t masses2 9 any *ange to :i* an atom is subject$ its mass does n *ange4 #c4 ,:5 two or m elem5ts unite to =m a comp\nd1 ! action consi/s 9 ! union ( a def9ite small numb] ( atoms ( ea* elem5t to =m a small p>ticle ( ! comp\nd4 ,! smalle/ p>ticles ( a giv5 comp\nd are !re=e exactly alike 9 ! numb] & k9ds ( atoms :i* !y conta91 & l>g] masses ( ! sub/ances are simply aggregations ( ^! lea/ p>ticles4 ,molecules & atoms4 ,dalton appli$ ! "n atom n only to ! m9ute p>ticles ( ! elem5ts b also to ! lea/ p>ticles ( comp\nds4 ,lat] ,avogadro1 an ,italian sci5ti/1 po9t$ out ! fact t ! two are diff]5t1 s9ce ! smalle/ p>ticle ( an elem5t is a unit1 :ile t ( a comp\nd mu/ h at lea/ two units 9 x4 ,he sugge/$ ! "n molecule = ! lea/ p>ticle ( a comp\nd :i* c exi/1 reta9+ ! "n atom = ! smalle/ p>ticle ( an elem5t4 ,9 accordance ) ?is di/9ction1 we may def9e ! atom & ! molecule z foll[s3 ,an atom is ! smalle/ p>ticle ( an elem5t :i* c exi/4 ,a molecule is ! smalle/ p>ticle ( a comp\nd :i* c exi/4 ,x w be %[n 9 a subsequ5t *apt] t sometimes two or m atoms ( ! same elem5t unite ) ea* o!r to =m molecules ( ! elem5t4 ,:ile ! t]m atom1 !re=e1 is applicable only to elem5ts1 ! t]m molecule is applicable bo? to elem5ts & comp\nds4 ,! atomic hypo!sis & ! laws ( matt]4 ,suppos+ ! atomic hypo!sis to be true1 let u n[ see if x is 9 h>mony ) ! laws ( matt]4 #a4 ,! atomic hypo!sis & ! law ( cons]vation ( matt]4 ,x is evid5t t if ! atoms nev] *ange _! masses 9 any *ange :i* !y und]go1 ! total quantity ( matt] c nev] *ange & ! law ( cons]vation ( matt] mu/ foll[4 #b4 ,! atomic hypo!sis & ! law ( def9ite composition4 ,accord+ to ! ?ird supposition1 :5 iron comb9es ) sulphur ! union is betwe5 def9ite numb]s ( ! two k9ds ( atoms4 ,9 ! simple/ case "o atom ( ! "o elem5t comb9es ) "o atom ( ! o!r4 ,if ! sulphur & ! iron atoms nev] *ange _! respective masses :5 !y unite to =m a molecule ( iron sulphide1 all iron sulphide molecules w h equal am\nts ( iron 9 !m & also ( sulphur4 ,consequ5tly any mass made up ( iron sulphide molecules w h ! same fraction ( iron by weight z d ! individual iron sulphide molecules4 ,iron sulphide1 f :atev] s\rce1 w h ! same composition1 :i* is 9 accordance ) ! law ( def9ite composition4 #c4 ,! atomic hypo!sis & ! law ( multiple proportion4 ,b ?is simple/ case may n always be ! only "o4 ,"u o!r conditions "o atom ( iron might comb9e ) two ( sulphur to =m a molecule ( a second comp\nd4 ,9 su* a case ! "o atom ( iron w\ld be 9 comb9ation ) twice ! mass ( sulphur t is 9 ! fir/ comp\nd1 s9ce ! sulphur atoms all h equal masses4 ,:at is true = "o molecule w be true = any numb] ( !m2 consequ5tly :5 su* quantities ( ^! two comp\nds are select$ z are f\nd to conta9 ! same am\nt ( iron1 ! "o w conta9 twice z mu* sulphur z ! o!r4 ,! comb9ation betwe5 ! atoms may ( c\rse take place 9 o!r simple ratios4 ,= example1 two atoms ( "o elem5t might comb9e ) ?ree or ) five ( ! o!r4 ,9 all su* cases x is cle> t ! law ( multiple proportion mu/ hold true4 ,= on select+ su* numb]s ( ! two k9ds ( molecules z h ! same numb] ( ! "o k9d ( atoms1 ! numb]s ( ! o!r k9d ( atoms w /& 9 "s simple ratio to ea* o!r1 & _! weights w !re=e /& 9 ! same simple ratio4 ,te/+ ! hypo!sis4 ,ef=ts h be5 made to f9d comp\nds :i* d n con=m to ^! laws1 b all su* attempts h result$ 9 failure4 ,if su* comp\nds %\ld be f\nd1 ! laws w\ld be no long] true1 & ! hypo!sis ( ,dalton w\ld cease to possess value4 ,:5 an hypo!sis has be5 te/$ 9 e way 9 :i* exp]im5t c te/ x1 & is /ill f\nd to be 9 h>mony ) ! facts 9 ! case1 x is t]m$ a !ory4 ,we n[ speak ( ! atomic !ory r ?an ( ! atomic hypo!sis4 ,value ( a !ory4 ,! value ( a !ory is tw(old4 ,x aids 9 ! cle> und]/&+ ( ! laws ( nature because x gives an intellig5t idea z to :y ^! laws %\ld be 9 op]ation4 ,a !ory also leads to discov]ies4 ,x usually happ5s t 9 te/+ a !ory mu* valuable "w is done1 & _m new facts are discov]$4 ,almo/ any !ory 9 expla9+ giv5 laws w involve a numb] ( consequ5ces ap>t f ! laws x seeks to expla94 ,exp]im5t w soon %[ :e!r ^! facts are z ! !ory pr$icts !y w be4 ,?us ,dalton's atomic !ory pr$ict$ _m prop]ties ( gases :i* exp]im5t has s9ce v]ifi$4 ,atomic weights4 ,x w\ld be ( great advantage 9 ! /udy ( *emi/ry if we c\ld det]m9e ! weights ( ! diff]5t k9ds ( atoms4 ,x is evid5t t ?is _c be done directly4 ,!y are s small t !y _c be se5 ev5 ) a mo/ p[]ful microscope4 ,x is calculat$ t x w\ld take #bjj1jjj1jjj hydrog5 atoms plac$ side by side to make a r[ "o c5timet] long4 ,no balance c weigh su* m9ute objects4 ,x is possible1 h[ev]1 to det]m9e _! relative weights1--t is1 h[ mu* heavi] "o is ?an ano!r4 ,^! relative weights ( ! atoms are spok5 ( z ! atomic weights ( ! elem5ts4 ,if elem5ts 7 able to comb9e 9 only "o way1--"o atom ( "o ) "o atom ( ano!r1--! problem ( det]m9+ ! atomic weights w\ld be v simple4 ,we %\ld m]ely h to take "s "o conv5i5t elem5t z a /&>d1 & f9d by exp]im5t h[ mu* ( ea* o!r elem5t w\ld comb9e ) a fix$ weight ( x4 ,! ratios ?us f\nd w\ld be ! same ratios z ^? betwe5 ! atoms ( ! elem5ts1 & ?us we %\ld h _! relative atomic weights4 ,! law ( multiple proportion calls att5tion to ! fact t ! atoms comb9e 9 o!r ratios ?an #a3 #a1 & !re is no direct way ( tell+ :i* "o1 if any1 ( ! sev]al comp\nds 9 a giv5 case is ! "o consi/+ ( a s+le atom ( ea* elem5t4 ,if "s way 7 to be f\nd ( tell+ h[ mu* heavi] ! entire molecule ( a comp\nd is ?an ! atom *os5 z a /&>d1--t is1 ( det]m9+ ! molecul> weights ( comp\nds1--! problem c\ld be solv$1 ?\gh its solution w\ld n be an entirely simple matt]4 ,!re are ways ( det]m9+ ! molecul> weights ( comp\nds1 & !re are o!r exp]im5ts :i* ?r[ light directly ^u ! relative weights ( ! atoms4 ,^! me?ods _c be describ$ until ! facts ^u :i* !y re/ h be5 /udi$4 ,x w be suffici5t = ! pres5t to assume t ^! me?ods are tru/wor?y4 ,/&>d = atomic weights4 ,s9ce ! atomic weights are m]ely relative to "s "o elem5t *os5 z a /&>d1 x is evid5t t any "o ( ! elem5ts may s]ve z ?is /&>d & t any conv5i5t value may be assign$ to its atom4 ,at "o "t oxyg5 0 tak5 z ?is /&>d1 ) ! value #ajj1 & ! atomic weights ( ! o!r elem5ts 7 express$ 9 t]ms ( ?is /&>d4 ,x w\ld seem m rational to take ! elem5t ( smalle/ atomic weight z ! /&>d & give x unit value2 accord+ly hydrog5 0 tak5 z ! /&>d ) an atomic weight ( #a4 ,v rec5tly1 h[ev]1 ?is unit has be5 replac$ by oxyg51 ) an atomic weight ( #af4 ,:y oxyg5 is *os5 z ! /&>d = atomic weights4 ,9 ! det]m9ation ( ! atomic weight ( an elem5t x is necess>y to f9d ! weight ( ! elem5t :i* comb9es ) a def9ite weight ( ano!r elem5t1 pref]ably ! elem5t *os5 z ! /&>d4 ,s9ce oxyg5 comb9es ) ! elem5ts f> m readily ?an does hydrog5 to =m def9ite comp\nds1 x is f> bett] adapt$ = ! /&>d elem5t1 & has accord+ly replac$ hydrog5 z ! /&>d4 ,any def9ite value might be giv5 to ! weight ( ! oxyg5 atom4 ,9 assign+ a value to x1 h[ev]1 x is conv5i5t to *oose a :ole numb]1 & z small a numb] z possible )\t mak+ ! atomic weight ( any o!r elem5t less ?an unity4 ,= ^! reasons ! numb] #af has be5 *os5 z ! atomic weight ( oxyg54 ,?is makes ! atomic weight ( hydrog5 equal to #a4jjh1 s t !re is b little diff]5ce betwe5 tak+ oxyg5 z #af & hydrog5 z #a = ! unit4 ,! atomic weights ( ! elem5ts are giv5 9 ! ,app5dix4 ,,ex]cises #a4 ,two comp\nds 7 f\nd to h ! foll[+ compositions3 7a7 oxyg5 #fi4ec1 nitrog5 #cj4dg2 7b7 oxyg5 #ec4bg1 nitrog5 #df4gc4 ,%[ t ! law ( multiple proportion holds 9 ?is case4 #b4 ,two comp\nds 7 f\nd to h ! foll[+ compositions3 7a7 oxyg5 #dc4fd1 phosphorus #ef4cf2 7b7 oxyg5 #ef4ce1 phosphorus #dc4fe4 ,%[ t ! law ( multiple proportion holds 9 ?is case4 #c4 ,:y did ,dalton assume t all ! atoms ( a giv5 elem5t h ! same weight8 ,,*apt] ,,vi ,,*emical ,,equations ,,& ,,calculations ,=mulas4 ,s9ce ! molecule ( any *emical comp\nd consi/s ( a def9ite numb] ( atoms1 & ?is numb] nev] *anges )\t de/roy+ ! id5tity ( ! comp\nd1 x is v conv5i5t to repres5t ! composition ( a comp\nd by indicat+ ! composition ( its molecules4 ,?is c be done v easily by us+ ! symbols ( ! atoms to indicate ! numb] & ! k9d ( ! atoms :i* con/itute ! molecule4 ,hg,o w 9 ?is way repres5t m]curic oxide1 a molecule ( :i* has be5 f\nd to conta9 #a atom ea* ( m]cury & oxyg54 ,h#b,o w repres5t wat]1 ! molecules ( :i* consi/ ( #a atom ( oxyg5 & #b ( hydrog51 ! subscript figure indicat+ ! numb] ( ! atoms ( ! elem5t ^: symbol prec$es x4 ,h#b,,s#d w /& = sulphuric acid1 ! molecules ( :i* conta9 #b atoms ( hydrog51 #a ( sulphur1 & #d ( oxyg54 ,! comb9ation ( symbols :i* repres5ts ! molecule ( a sub/ance is call$ its =mula4 ,equations4 ,:5 a giv5 sub/ance und]goes a *emical *ange x is possible to repres5t ?is *ange by ! use ( su* symbols & =mulas4 ,9 a =m] *apt] x 0 %[n t m]curic oxide decomposes :5 heat$ to =m m]cury & oxyg54 ,?is may be express$ v briefly 9 ! =m ( ! equation 7#a7 ,hg,o ,hg ,o4 ,:5 wat] is electrolyz$ two new sub/ances1 hydrog5 & oxyg51 are =m$ f x4 ,?is /atem5t 9 ! =m ( an equation is 7#b7 ,h#b,o #b;,h ,o4 ,! coeffici5t be=e ! symbol = hydrog5 indicates t a s+le molecule ( wat] yields two atoms ( hydrog5 on decomposition4 ,9 l mann] ! comb9ation ( sulphur ) iron is express$ by ! equation 7#c7 ,fe ,s ,fe,s4 ,! decomposition ( potassium *lorate by heat takes place z repres5t$ by ! equation 7#d7 ,k,cl,o#c ,k,cl #c,o4 ,read+ ( equations4 ,s9ce equations are simply a k9d ( %or?& way ( indicat+ *emical *anges :i* occur "u c]ta9 conditions1 9 read+ an equation ! full /atem5t = :i* x /&s %\ld be giv54 ,equation 7#a7 %\ld be read1 ,m]curic oxide :5 heat$ gives m]cury & oxyg52 equation 7#b7 is equival5t to ! /atem5t1 ,:5 electrolyz$1 wat] produces hydrog5 & oxyg52 equation 7#c71 ,:5 heat$ toge!r iron & sulphur unite to =m iron sulphide2 equation 7#d71 ,potassium *lorate :5 heat$ yields potassium *loride & oxyg54 ,k requir$ = writ+ equations4 ,9 ord] to write su* equations correctly1 a consid]able am\nt ( exact k is requir$4 ,?us1 9 equation 7#a7 ! fact t r$ oxide ( m]cury has ! composition repres5t$ by ! =mula ,hg,o1 t x is decompos$ by heat1 t 9 ?is decomposition m]cury & oxyg5 are =m$ & no o!r products1--all ^! facts mu/ be asc]ta9$ by exact exp]im5t be=e ! equation c be writt54 ,an equation express+ ^! facts w !n h mu* value4 ,hav+ obta9$ an equation describ+ ! conduct ( m]curic oxide on be+ heat$1 x w n d to assume t o!r oxides w behave 9 l mann]4 ,iron oxide 7,fe,o7 resembles m]curic oxide 9 _m respects1 b x und]goes no *ange at all :5 heat$4 ,manganese dioxide1 ! black sub/ance us$ 9 ! prep>ation ( oxyg51 has ! =mula ,mn,o#b4 ,:5 ?is sub/ance is heat$ oxyg5 is set free1 b ! metal manganese is n lib]at$2 in/ead1 a diff]5t oxide ( manganese conta9+ less oxyg5 is produc$4 ,! equation repres5t+ ! reaction is #c,mn,o#b ,mn#c,o#d #b,o4 ,classes ( reactions4 ,:5 a *emical *ange takes place 9 a sub/ance ! sub/ance is said to und]go a reaction4 ,al?\gh a great _m diff]5t reactions w be met 9 ! /udy ( *emi/ry1 !y may all be gr\p$ "u ! foll[+ heads4 #a4 ,addition4 ,?is is ! simple/ k9d ( *emical action4 ,x consi/s 9 ! union ( two or m sub/ances to produce a new sub/ance4 ,! comb9ation ( iron ) sulphur is an example3 ,fe ,s ,fe,s4 #b4 ,decomposition4 ,?is is ! rev]se ( addition1 ! sub/ance und]go+ reaction be+ p>t$ into its con/itu5ts4 ,! decomposition ( m]curic oxide is an example3 ,hg,o ,hg ,o4 #c4 ,sub/itution4 ,x is sometimes possible = an elem5t 9 ! free /ate to act ^u a comp\nd 9 su* a way t x takes ! place ( "o ( ! elem5ts ( ! comp\nd1 lib]at+ x 9 turn4 ,9 ! /udy ( ! elem5t hydrog5 x 0 po9t$ out t hydrog5 is mo/ conv5i5tly prep>$ by ! action ( sulphuric or hydro*loric acid ^u z9c4 ,:5 sulphuric acid is us$ a sub/ance call$ z9c sulphate1 hav+ ! composition repres5t$ by ! =mula ,zn,s,o#d1 is =m$ toge!r ) hydrog54 ,! equation is ,zn ,h#b,,s#d ,zn,s,o#d #b;,h4 ,:5 hydro*loric acid is us$ z9c *loride & hydrog5 are ! products ( reaction3 ,zn #b;,h,cl ,zn,cl#b #b;,h4 ,:5 iron is us$ 9 place ( z9c ! equation is ,fe ,h#b,,s#d ,fe,s,o#d #b;,h4 ,^! reactions are q simil>1 z is app>5t f an exam9ation ( ! equations4 ,9 ea* case #a atom ( ! metal replaces #b atoms ( hydrog5 9 ! acid1 & ! hydrog5 escapes z a gas4 ,:5 an elem5t 9 ! free /ate1 su* z ! z9c 9 ! equations j giv51 takes ! place ( "s "o elem5t 9 a comp\nd1 sett+ x free f *emical comb9ation1 ! act is call$ sub/itution4 ,o!r reactions illu/rat+ sub/itution are ! action ( sodium on wat]1 ,na ,h#b,o ,na,o,h ,h2 & ! action ( heat$ iron ^u wat]1 #c;,fe #d;,h#b,o ,fe#c,o#d #h;,h4 #d4 ,d\ble decomposition4 ,:5 b>ium dioxide 7,ba,o#b7 is treat$ ) sulphuric acid two comp\nds are =m$1 namely1 hydrog5 dioxide 7,h#b,o#b7 & b>ium sulphate 7,ba,s,o#d74 ,! equation is ,ba,o#b ,h#b,,s#d ,ba,s,o#d ,h#b,o#b4 ,9 ?is reaction x w be se5 t ! two elem5ts b>ium & hydrog5 simply ex*ange places4 ,su* a reaction is call$ a d\ble decomposition4 ,we %all meet ) _m examples ( ?is k9d ( *emical reactions4 ,*emical equations are quantitative4 ,! use ( symbols & =mulas 9 express+ *emical *anges has ano!r great advantage4 ,?us1 accord+ to ! equation ,h#b,o #b;,h ,o1 #a molecule ( wat] is decompos$ into #b atoms ( hydrog5 & #a atom ( oxyg54 ,b1 z we h se51 ! relative weights ( ! atoms are kn[n1 t ( hydrog5 be+ #a4jjh1 :ile t ( oxyg5 is #af4 ,! molecule ( wat]1 be+ compos$ ( #b atoms ( hydrog5 & #a atom ( oxyg51 mu/ !re=e weigh relatively #b4jaf #af1 or #ah4jaf4 ,! am\nt ( hydrog5 9 ?is molecule mu/ be #b4jaf_/ah4jaf1 or #aa4ah ( ! :ole1 :ile ! am\nt ( oxyg5 mu/ be #af_/ah4jah1 or #hh4hb ( ! :ole4 ,n[1 s9ce any def9ite quantity ( wat] is simply ! sum ( a great _m molecules ( wat]1 x is pla9 t ! fractions repres5t+ ! relative am\nts ( hydrog5 & oxyg5 pres5t 9 a molecule mu/ likewise express ! relative am\nts ( hydrog5 & oxyg5 pres5t 9 any quantity ( wat]4 ,?us1 = example1 9 #bj g4 ( wat] !re are #b4jaf_/ah4jaf #bj1 or #b4bch g4 ( hydrog51 & #af_/ah4jaf #bj1 or #ag4gfb g4 ( oxyg54 ,^! results 9 ref]5ce to ! composition ( wat] ( c\rse agree exactly ) ! facts obta9$ by ! exp]im5ts describ$ 9 ! *apt] on wat]1 = x is because ( ^? exp]im5ts t ! values #a4jjh & #af are giv5 to hydrog5 & oxyg5 respectively4 ,x is (t5 easi] to make calculations ( ?is k9d 9 ! =m ( a proportion r ?an by fractions4 ,s9ce ! molecule ( wat] & ! two atoms ( hydrog5 :i* x conta9s h ! ratio by weight ( #ah4jaf3 #b4jaf1 any mass ( wat] has ! same ratio betwe5 its total weight & ! weight ( ! hydrog5 9 x4 ,h5ce1 to f9d ! numb] ( grams 7x7 ( hydrog5 9 #bj g4 ( wat]1 we h ! proportion #ah4jaf 3 #b4jaf 33 #bj g4 3 x 7grams ( hydrog574 ,solv+ = x1 we get #b4bch = ! numb] ( grams ( hydrog54 ,simil>ly1 to f9d ! am\nt 7x7 ( oxyg5 pres5t 9 ! #bj g4 ( wat]1 we h ! proportion #ah4jaf 3 #af 33 #bj 3 x f :i* we f9d t x #ag4gfb g4 ,aga91 suppose we wi% to f9d :at weight ( oxyg5 c be obta9$ f #ae g4 ( m]curic oxide4 ,! equation repres5t+ ! decomposition ( m]curic oxide is ,hg,o ,hg ,o4 ,! relative weights ( ! m]cury & oxyg5 atoms are respectively #bjj & #af4 ,! relative weight ( ! m]curic oxide molecule mu/ !re=e be ! sum ( ^!1 or #baf4 ,! molecule ( m]curic oxide & ! atom ( oxyg5 :i* x conta9s h ! ratio #baf3 #af4 ,?is same ratio mu/ !re=e hold betwe5 ! weight ( any giv5 quantity ( m]curic oxide & t ( ! oxyg5 :i* x conta9s4 ,h5ce1 to f9d ! weight ( oxyg5 9 #ae g4 ( m]curic oxide1 we h ! proportion #baf 3 #af 33 #ae 3 x 7grams ( oxyg574 ,on ! o!r h&1 suppose we wi% to prep>e1 say1 #bj g4 ( oxyg54 ,! problem is to f9d out :at weight ( m]curic oxide w yield #bj g4 ( oxyg54 ,! foll[+ proportion evid5tly holds #baf 3 #af 33 x 7grams ( m]curic oxide7 3 #bj2 f :i* we get x #bgj4 ,9 ! prep>ation ( hydrog5 by ! action ( sulphuric acid ^u z9c1 accord+ to ! equation1 ,zn ,h#b,,s#d ,zn,s,o#d #b ,h1 suppose t #ej g4 ( z9c are available2 let x be requir$ to calculate ! weight ( hydrog5 :i* c be obta9$4 ,x w be se5 t #a atom ( z9c w lib]ate #b atoms ( hydrog54 ,! ratio by weight ( a z9c to an hydrog5 atom is #fe4d3 #a4jjh2 ( #a z9c atom to #b hydrog5 atoms1 #fe4d3 #b4jaf4 ,z9c & hydrog5 w be relat$ 9 ?is reaction 9 ?is same ratio1 h[ev] _m atoms ( z9c are conc]n$4 ,consequ5tly 9 ! proportion #fe4d 3 #b4jaf 33 #ej 3 x1 x w be ! weight ( hydrog5 set free by #ej g4 ( z9c4 ,! weight ( z9c sulphate produc$ at ! same "t c be f\nd f ! proportion #fe4d 3 #afa4df 33 #ej 3 x2 :]e #afa4df is ! molecul> weight ( ! z9c sulphate1 & x ! weight ( z9c sulphate =m$4 ,9 l mann]1 ! weight ( sulphuric acid us$ up c be calculat$ f ! proportion #fe4d 3 #ih4jgf 33 #ej 3 x4 ,^! simple calculations are possible because ! symbols & =mulas 9 ! equations repres5t ! relative weights ( ! sub/ances conc]n$ 9 a *emical reaction4 ,:5 once ! relative weights ( ! atoms h be5 det]m9$1 & x has be5 agre$ to all[ ! symbols to /& = ^! relative weights1 an equation or =mula mak+ use ( ! symbols becomes a /atem5t ( a def9ite num]ical fact1 & calculations c be bas$ on x4 ,*emical equations n algebraic4 ,al?\gh *emical equations are quantitative1 x mu/ be cle>ly und]/ood t !y are n algebraic4 ,a glance at ! equations #g #d #aa1 #h #e #i #d w %[ at once t !y are true4 ,! equations ,hg,o ,hg ,o1 ,fe,o ,fe ,o are equally true 9 an algebraic s5se1 b exp]im5t %[s t only ! fir/ is true *emically1 = iron oxide 7,fe,o7 _c be directly decompos$ into iron & oxyg54 ,only su* equations z h be5 f\nd by c>eful exp]im5t to express a real *emical trans=mation1 true bo? = ! k9ds ( sub/ances z well z = ! weights1 h any value4 ,*emical =mulas & equations1 !re=e1 are a concise way ( repres5t+ qualitatively & quantitatively facts :i* h be5 f\nd by exp]im5t to be true 9 ref]5ce to ! composition ( sub/ances & ! *anges :i* !y und]go4 ,=mulas repres5t+ wat] ( cry/allization4 ,an exam9ation ( sub/ances conta9+ wat] ( cry/allization has %[n t 9 e case ! wat] is pres5t 9 su* proportion by weight z c readily be repres5t$ by a =mula4 ,= example1 copp] sulphate 7,cu,s,o#d7 & wat] comb9e 9 ! ratio ( #a molecule ( ! sulphate to #e ( wat]2 calcium sulphate 7,ca,s,o#d7 & wat] comb9e 9 ! ratio #a3 #b to =m gypsum4 ,^! facts are express$ by writ+ ! =mulas = ! two sub/ances ) a p]iod betwe5 !m4 ,?us ! =mula = cry/alliz$ copp] sulphate is ,cu,s,o#de;,h#b,o2 t ( gypsum is ,ca,s,o#db;,h#b,o4 ,heat ( reaction4 ,att5tion has frequ5tly be5 direct$ to ! fact t *emical *anges are usually accompani$ by heat *anges4 ,9 g5]al x has be5 f\nd t 9 e *emical action heat is ei!r absorb$ or giv5 (f4 ,by adopt+ a suitable unit = ! measurem5t ( heat1 ! heat *ange dur+ a *emical reaction c be express$ 9 ! equation = ! reaction4 ,heat _c be measur$ by ! use ( a !rmomet] alone1 s9ce ! !rmomet] measures ! int5sity ( heat1 n its quantity4 ,! easie/ way to measure a quantity ( heat is to note h[ w>m x w make a def9ite am\nt ( a giv5 sub/ance *os5 z a /&>d4 ,wat] has be5 *os5 z ! /&>d1 & ! unit ( heat is call$ a calorie4 ,a calorie is def9$ z ! am\nt ( heat requir$ to raise ! temp]ature ( "o gram ( wat] "o degree4 ,by means ( ?is unit x is easy to indicate ! heat *anges 9 a giv5 *emical reaction4 ,! equation #b;,h ,o ,h#b,o #fh1cjj cal4 means t :5 #b4jaf g4 ( hydrog5 comb9e ) #af g4 ( oxyg51 #ah4jaf g4 ( wat] are =m$ & #fh1cjj cal4 are set free4 ,c #b,s ,,cs#b - #ai1jjj cal4 means t an exp5diture ( #ai1jjj cal4 is requir$ to cause #ab g4 ( c>bon to unite ) #fd4ab g4 ( sulphur to =m #gf4ab g4 ( c>bon disulphide4 ,9 ^! equations x w be not$ t ! symbols /& = z _m grams ( ! sub/ance z !re are units 9 ! weights ( ! atoms repres5t$ by ! symbols4 ,?is is always und]/ood to be ! case 9 equations :]e ! heat ( reaction is giv54 ,conditions ( a *emical action are n indicat$ by equations4 ,equations d n tell ! conditions "u :i* a reaction w take place4 ,! equation ,hg,o ,hg ,o does n tell u t x is necess>y to keep ! m]curic oxide at a high temp]ature 9 ord] t ! decomposition may g on4 ,! equation ,zn #b;,h,cl ,zn,cl#b #b;,h 9 no way indicates ! fact t ! hydro*loric acid mu/ be dissolv$ 9 wat] be=e x w act ^u ! z9c4 ,f ! equation ,h ,cl ,h,cl x w\ld n be suspect$ t ! two gases hydrog5 & *lor9e w unite in/antly 9 ! sunlight1 b w /& mix$ 9 ! d>k a long "t )\t *ange4 ,x w !re=e be necess>y to pay mu* att5tion to ! details ( ! conditions "u :i* a giv5 reaction occurs1 z well z to ! expression ( ! reaction 9 ! =m ( an equation4 ,,ex]cises #a4 ,calculate ! p]c5tage composition ( ! foll[+ sub/ances3 7a7 m]curic oxide2 7b7 potassium *lorate2 7c7 hydro*loric acid2 7d7 sulphuric acid4 ,comp>e ! results obta9$ ) ! compositions z giv5 9 ,*apt]s ,,ii & ,,iii4 #b4 ,det]m9e ! p]c5tage ( copp]1 sulphur1 oxyg51 & wat] 9 copp] sulphate cry/als4 ,:at weight ( wat] c be obta9$ f #aej g4 ( ?is sub/ance8 #c4 ,:at weight ( z9c c be dissolv$ 9 #aj g4 ( sulphuric acid8 ,h[ mu* z9c sulphate w be =m$8 #d4 ,h[ _m lit]s ( hydrog5 measur$ "u /&>d conditions c be obta9$ f ! action ( #h g4 ( iron on #aj g4 ( sulphuric acid8 ,h[ mu* iron sulphate 7,fe,s,o#d7 w be =m$8 #e4 #aj g4 ( z9c 7 us$ 9 ! prep>ation ( hydrog52 :at weight ( iron w be requir$ to prep>e an equal volume8 #f4 ,h[ _m grams ( b>ium dioxide w be requir$ to prep>e #a kg4 ( common hydrog5 dioxide solution8 ,:at weight ( b>ium sulphate w be =m$ at ! same "t8 #g4 ,:at weight ( ! comp\nd ,mn#c,o#d w be =m$ by /rongly heat+ #be g4 ( manganese dioxide8 ,:at volume ( oxyg5 w be giv5 (f at ! same "t1 measur$ "u /&>d conditions8 #h4 7a7 ,:at is ! weight ( #ajj l4 ( hydrog5 measur$ 9 a laboratory 9 :i* ! temp]ature is #bj & pressure #gej mm48 7b7 ,:at weight ( sulphuric acid is necess>y to prep>e ?is am\nt ( hydrog58 7c7 ,! d5sity ( sulphuric acid is #a4hd4 ,express ! acid requir$ 9 7b7 9 cubic c5timet]s4 #i4 ,:at weight ( potassium *lorate is necess>y to furni% suffici5t oxyg5 to fill f\r #bjj cc4 bottles 9 y\r laboratory 7! gas to be collect$ ov] wat]78 ,,*apt] ,,vii ,,nitrog5 ,,& ,,! ,,r>e ,,elem5ts3 ,,argon1 ,,helium1 ,,neon1 ,,krypton1 ,,x5on ,hi/orical4 ,nitrog5 0 discov]$ by ! ,engli% *emi/ ,ru!r=d 9 #aggb4 ,a little lat] ,s*eele %[$ x to be a con/itu5t ( air1 & ,lavoisi] gave x ! "n azote1 signify+ t x w\ld n support life4 ,! "n nitrog5 0 aft]w>ds giv5 x because ( its pres5ce 9 saltpet] or nit]4 ,! t]m azote & symbol ,az are /ill reta9$ by ! ,fr5* *emi/s4 ,occurr5ce4 ,air is compos$ pr9cipally ( oxyg5 & nitrog5 9 ! free /ate1 ab\t #gh p>ts by volume out ( e #ajj p>ts be+ nitrog54 ,nitrog5 also occurs 9 nature 9 ! =m ( potassium nitrate 7,,kno#c7--;commonly call$ saltpet] or nit]--z well z 9 sodium nitrate 7,na,n,o#c74 ,nitrog5 is also an ess5tial con/itu5t ( all liv+ organisms2 = example1 ! human body conta9s ab\t #b4d ( nitrog54 ,prep>ation f air4 ,nitrog5 c be prep>$ f air by ! action ( "s sub/ance :i* w comb9e ) ! oxyg51 leav+ ! nitrog5 free4 ,su* a sub/ance mu/ be *os51 h[ev]1 z w comb9e ) ! oxyg5 to =m a product :i* is n a gas1 & :i* c be readily sep>at$ f ! nitrog54 ,! sub/ances mo/ commonly us$ = ?is purpose are phosphorus & copp]4 #a4 ,by ! action ( phosphorus4 ,! me?od us$ = ! prep>ation ( nitrog5 by ! action ( phosphorus is z foll[s3 ,! phosphorus is plac$ 9 a little porcela9 di%1 support$ on a cork & float$ on wat] 7,fig4 #bf74 ,x is !n ignit$ by contact ) a hot wire1 & imm$iately a bell j> or bottle is br\ght ov] x s z to conf9e a portion ( ! air4 ,! phosphorus comb9es ) ! oxyg5 to =m an oxide ( phosphorus1 kn[n z phosphorus p5toxide4 ,?is is a :ite solid :i* floats ab\t 9 ! bell j>1 b 9 a %ort "t x is all absorb$ by ! wat]1 leav+ ! nitrog54 ,! )drawal ( ! oxyg5 is indicat$ by ! ris+ ( ! wat] 9 ! bell j>4 ,illu/ration3 ,fig4 #bf #b4 ,by ! action ( copp]4 ,! oxyg5 pres5t 9 ! air may also be remov$ by pass+ air sl[ly ?r\gh a heat$ tube conta9+ copp]4 ,! copp] comb9es ) ! oxyg5 to =m copp] oxide1 :i* is a solid4 ,! nitrog5 passes on & may be collect$ ov] wat]4 ,nitrog5 obta9$ f air is n pure4 ,inasmu* z air1 9 addition to oxyg5 & nitrog51 conta9s small am\nts ( o!r gases1 & s9ce ! phosphorus z well z ! copp] removes only ! oxyg51 x is evid5t t ! nitrog5 obta9$ by ^! me?ods is nev] q pure4 ,ab\t #a ( ! product is compos$ ( o!r gases1 f :i* x is v difficult to sep>ate ! nitrog54 ,! impure nitrog5 s obta9$ may1 h[ev]1 be us$ = a /udy ( mo/ ( ! prop]ties ( nitrog51 s9ce ^! are n mat]ially affect$ by ! pres5ce ( ! o!r gases4 ,prep>ation f comp\nds ( nitrog54 ,pure nitrog5 may be obta9$ f c]ta9 comp\nds ( ! elem5t4 ,?us1 if heat is appli$ to ! comp\nd ammonium nitrite 7,,nh#d,,no#b71 ! *ange repres5t$ 9 ! foll[+ equation takes place3 ,,nh#d,,no#b #b;,h#b,o #b,n4 ,physical prop]ties4 ,nitrog5 is simil> to oxyg5 & hydrog5 9 t x is a colorless1 odorless1 & ta/eless gas4 ,"o lit] ( nitrog5 weighs #a4beja g4 ,x is almo/ insoluble 9 wat]4 ,x c be obta9$ 9 ! =m ( a colorless liquid hav+ a boil+ po9t ( -#aie at ord9>y pressure4 ,at -#bad x solidifies4 ,*emical prop]ties4 ,nitrog5 is *>act]iz$ by its in]tness4 ,x is nei!r combu/ible nor a support] ( combu/ion4 ,at ord9>y temp]atures x w n comb9e directly ) any ( ! elem5ts except "u r>e conditions4 ,at high] temp]atures x comb9es ) magnesium1 li?ium1 titanium1 & a numb] ( o!r elem5ts4 ,! comp\nds =m$ are call$ nitrides1 j z comp\nds ( an elem5t ) oxyg5 are call$ oxides4 ,:5 x is mix$ ) oxyg5 & subject$ to ! action ( electric sp>ks1 ! two gases sl[ly comb9e =m+ oxides ( nitrog54 ,a mixture ( nitrog5 & hydrog5 :5 treat$ simil>ly =ms ammonia1 a gase\s comp\nd ( nitrog5 & hydrog54 ,s9ce we are con/antly inhal+ nitrog51 x is evid5t t x is n poison\s4 ,nev]!less life w\ld be impossible 9 an atmosph]e ( pure nitrog5 on acc\nt ( ! exclusion ( ! necess>y oxyg54 ,argon1 helium1 neon1 krypton1 x5on4 ,^! are all r>e elem5ts occurr+ 9 ! air 9 v small quantities4 ,argon1 discov]$ 9 #ahid1 0 ! fir/ "o obta9$4 ,"l ,rayleigh1 an ,engli% sci5ti/1 :ile engag$ 9 det]m9+ ! exact weights ( v>i\s gases1 obs]v$ t ! nitrog5 obta9$ f ! air is slightly heavi] ?an pure nitrog5 obta9$ f its comp\nds4 ,aft] repeat+ 8 exp]im5ts _m times1 always ) ! same results1 ,rayleigh f9ally conclud$ t ! nitrog5 :i* he _h obta9$ f ! air 0 n pure1 b 0 mix$ ) a small am\nt ( "s unkn[n gas1 ! d5sity ( :i* is great] ?an t ( nitrog54 ,act+ on ?is assumption1 ,rayleigh1 toge!r ) ! ,engli% *emi/ ,ramsay1 attempt$ to sep>ate ! nitrog5 f ! unkn[n gas4 ,kn[+ t nitrog5 w\ld comb9e ) magnesium1 !y pass$ ! nitrog5 obta9$ f ! air & fre$ f all kn[n sub/ances ?r\gh tubes conta9+ magnesium heat$ to ! necess>y temp]ature4 ,aft] repeat+ ?is op]ation1 !y f9ally succe$$ 9 obta9+ f ! atmosph]ic nitrog5 a small volume ( gas :i* w\ld n comb9e ) magnesium & h5ce c\ld n be nitrog54 ,?is prov$ to be a new elem5t1 to :i* !y gave ! "n argon4 ,z pr$ict$1 ?is new elem5t 0 f\nd to be heavi] ?an nitrog51 its d5sity z comp>$ ) hydrog5 z a /&>d be+ approximately #bj1 t ( nitrog5 be+ only #ad4 ,ab\t #a ( ! atmosph]ic nitrog5 prov$ to be argon4 ,! new elem5t is *>act]iz$ by hav+ no aff9ity = o!r elem5ts4 ,ev5 "u ! mo/ favorable conditions x has n be5 made to comb9e ) any o!r elem5t4 ,on ?is acc\nt x 0 giv5 ! "n argon1 signify+ lazy or idle4 ,l nitrog51 x is colorless1 odorless1 & ta/eless4 ,x has be5 liquefi$ & solidifi$4 ,its boil+ po9t is -#ahg4 ,helium 0 fir/ f\nd 9 ! gases expell$ f c]ta9 m9]als by heat+4 ,?r\gh ! ag5cy ( ! spectroscope x _h be5 kn[n to exi/ 9 ! sun long be=e its pres5ce on ! e>? _h be5 demon/rat$1--a fact sugge/$ by ! "n helium1 signify+ ! sun4 ,its exi/5ce 9 traces 9 ! atmosph]e has also be5 prov54 ,x 0 fir/ liquefi$ by ,onnes 9 ,july1 #aijh4 ,its boil+ po9t1 namely -#bfi1 is ! l[e/ temp]ature yet rea*$4 ,! rema9+ elem5ts ( ?is gr\p--neon1 krypton1 & x5on--h be5 obta9$ f liquid air4 ,:5 liquid air is all[$ to boil1 ! con/itu5ts :i* are ! mo/ difficult to liquefy1 & :i* !re=e h ! l[e/ boil+ po9ts1 vaporize fir/1 foll[$ by ! o!rs 9 ! ord] ( _! boil+ po9ts4 ,x is possible 9 ?is way to make at lea/ a p>tial sep>ation ( ! air into its con/itu5ts1 & ,ramsay ?us succe$$ 9 obta9+ f liquid air n only ! kn[n con/itu5ts1 includ+ argon & helium1 b also ! new elem5ts1 neon1 krypton1 & x5on4 ,^! elem5ts1 z well z helium1 all prov$ to be simil> to argon 9 t !y are )\t *emical activity1 app>5tly =m+ no comp\nds :atev]4 ,! p]c5tages pres5t 9 ! air are v small4 ,! names1 neon1 krypton1 x5on1 signify respectively1 new1 hidd51 /rang]4 ,,ex]cises #a4 ,h[ c\ld y di/+ui% betwe5 oxyg51 hydrog51 & nitrog58 #b4 ,calculate ! relative weights ( nitrog5 & oxyg52 ( nitrog5 & hydrog54 #c4 ,9 ! prep>ation ( nitrog5 f ! air1 h[ w\ld hydrog5 d z a sub/ance = ! removal ( ! oxyg58 #d4 ,:at weight ( nitrog5 c be obta9$ f #aj l4 ( air measur$ "u ! conditions ( temp]ature & pressure :i* prevail 9 y\r laboratory8 #e4 ,h[ _m grams ( ammonium nitrite are necess>y 9 ! prep>ation ( #bj l4 ( nitrog5 measur$ ov] wat] "u ! conditions ( temp]ature & pressure :i* prevail 9 y\r laboratory8 #f4 ,if #aj l4 ( air1 measur$ "u /&>d conditions1 is pass$ ov] #ajj g4 ( hot copp]1 h[ mu* w ! copp] ga9 9 weight8 ,illu/ration3 ,,william ,,ramsay 7,scot*7 7#ahee-7 ,has made _m /udies 9 ! physical prop]ties ( sub/ances2 discov]$ helium2 toge!r ) ,"l ,rayleigh & o!rs he discov]$ argon1 krypton1 x5on1 & neon2 has contribut$ l>gely to ! k ( radio-active sub/ances1 %[+ t radium gradually gives rise to helium2 pr(essor at ,univ]sity ,college1 ,london ,,*apt] ,,viii ,,! ,,atmosph]e ,atmosph]e & air4 ,! t]m atmosph]e is appli$ to ! gase\s envelope surr\nd+ ! e>?4 ,! t]m air is g5]ally appli$ to a limit$ portion ( ?is envelope1 al?\gh ! two words are (t5 us$ int]*angeably4 ,_m ref]5ces h already be5 made to ! composition & prop]ties ( ! atmosph]e4 ,^! /atem5ts mu/ n[ be collect$ & discuss$ some:at m 9 detail4 ,air =m]ly reg>d$ z an elem5t4 ,l wat]1 air 0 at fir/ reg>d$ z elem5t>y 9 "*4 ,ne> ! close ( ! eighte5? c5tury ,s*eele1 ,prie/ley1 & ,lavoisi] %[$ by _! exp]im5ts t x is a mixture ( at lea/ two gases1--^? :i* we n[ call oxyg5 & nitrog54 ,by burn+ sub/ances 9 an inclos$ volume ( air & not+ ! contraction 9 volume due to ! removal ( ! oxyg51 !y 7 able to det]m9e ) "s accuracy ! relative volumes ( oxyg5 & nitrog5 pres5t 9 ! air4 ,! con/itu5ts ( ! atmosph]e4 ,! con/itu5ts ( ! atmosph]e may be divid$ into two g5]al gr\ps3 ^? :i* are ess5tial to life & ^? :i* are n ess5tial4 #a4 ,con/itu5ts ess5tial to life4 ,9 addition to oxyg5 & nitrog5 at lea/ two o!r sub/ances1 namely1 c>bon dioxide & wat] vapor1 mu/ be pres5t 9 ! atmosph]e 9 ord] t life may exi/4 ,! =m] ( ^! is a gase\s comp\nd ( c>bon & oxyg5 hav+ ! =mula ,,co#b4 ,its prop]ties w be discuss$ 9 detail 9 ! *apt] on ! comp\nds ( c>bon4 ,its pres5ce 9 ! air may be %[n by caus+ ! air to bubble ?r\gh a solution ( calcium hydroxide 7,ca7,,oh7#b71 commonly call$ lime wat]4 ,! c>bon dioxide comb9es ) ! calcium hydroxide 9 accordance ) ! foll[+ equation3 ,ca7,,oh7#b ,,co#b ,ca,c,o#c ,h#b,o4 ,! result+ calcium c>bonate 7,ca,c,o#c7 is insoluble 9 wat] & sep>ates 9 ! =m ( a :ite p[d]1 :i* causes ! solution to appe> milky4 ,! pres5ce ( wat] vapor is readily %[n by its cond5sation on cold objects z well z by ! fact t a bit ( calcium *loride :5 expos$ to ! air becomes moi/1 & may ev5 dissolve 9 ! wat] absorb$ f ! air4 #b4 ,con/itu5ts n ess5tial to life4 ,9 addition to ! ess5tial con/itu5ts1 ! air conta9s small p]c5tages ( v>i\s o!r gases1 ! pres5ce ( :i* s f> z is kn[n is n ess5tial to life4 ,?is li/ includes ! r>e elem5ts1 argon1 helium1 neon1 krypton1 & x5on2 also hydrog51 ammonia1 hydrog5 dioxide1 & probably ozone4 ,c]ta9 m9ute =ms ( life 7g]ms7 are also pres5t1 ! decay ( organic matt] be+ due to _! pres5ce4 ,function ( ea* ( ! ess5tial con/itu5ts4 7#a7 ,! oxyg5 directly supports life ?r\gh respiration4 7#b7 ,! nitrog51 on acc\nt ( its inactivity1 s]ves to dilute ! oxyg51 & :ile contr>y to ! old] views1 x is possible t life might cont9ue to exi/ 9 ! abs5ce ( ! atmosph]ic nitrog51 yet ! conditions ( life w\ld be entirely *ang$4 ,moreov]1 nitrog5 is an ess5tial con/itu5t ( all animal & plant life4 ,x 0 =m]ly suppos$ t nei!r animals nor plants c\ld assimilate ! free nitrog51 b x has be5 %[n rec5tly t ! plants ( at lea/ "o natural ord]1 ! ,legum9os1 to :i* belong ! beans1 peas1 & clov]1 h ! p[] ( directly assimilat+ ! free nitrog5 f ! atmosph]e4 ,?is is accompli%$ ?r\gh ! ag5cy ( gr\ps ( bact]ia1 :i* =m colonies 9 little tub]cles on ! roots ( ! plants4 ,^! bact]ia probably assi/ 9 ! absorption ( nitrog5 by *ang+ ! free nitrog5 into comp\nds :i* c be assimilat$ by ! plant4 ,fig4 #bg %[s ! tub]cles on ! roots ( a v>iety ( bean4 7#c7 ,! pres5ce ( wat] vapor 9 ! air is necess>y to prev5t excessive evaporation f bo? plants & animals4 7#d7 ,c>bon dioxide is an ess5tial plant food4 ,illu/ration3 ,fig4 #bg ,! quantitative analysis ( air4 ,a numb] ( diff]5t me?ods h be5 devis$ = ! det]m9ation ( ! p]c5tages ( ! con/itu5ts pres5t 9 ! atmosph]e4 ,among ^! are ! foll[+4 #a4 ,det]m9ation ( oxyg54 7#a7 ,! oxyg5 is )drawn f a measur$ volume ( air inclos$ 9 a tube1 by means ( phosphorus4 ,to make ! det]m9ation1 a graduat$ tube is fill$ ) wat] & inv]t$ 9 a vessel ( wat]4 ,air is introduc$ into ! tube until x is p>tially fill$ ) ! gas4 ,! volume ( ! inclos$ air is c>efully not$ & r$uc$ to /&>d conditions4 ,a small piece ( phosphorus is atta*$ to a wire & br\ght )9 ! tube z %[n 9 ,fig4 #bh4 ,aft] a few h\rs ! oxyg5 9 ! inclos$ air w h comb9$ ) ! phosphorus1 ! wat] ris+ to take its place4 ,! phosphorus is remov$ & ! volume is aga9 not$ & r$uc$ to /&>d conditions4 ,! contraction 9 ! volume ( ! air is equal to ! volume ( oxyg5 absorb$4 ,illu/ration3 ,fig4 #bh 7#b7 ,! oxyg5 may also be e/imat$ by pass+ a measur$ volume ( air ?r\gh a tube conta9+ copp] heat$ to a high temp]ature4 ,! oxyg5 9 ! air comb9es ) ! copp] to =m copp] oxide 7,cu,o74 ,h5ce ! increase 9 ! weight ( ! copp] equals ! weight ( ! oxyg5 9 ! volume ( air tak54 7#c7 ,a m accurate me?od is ! foll[+4 ,a eudiomet] tube is fill$ ) m]cury & inv]t$ 9 a vessel ( ! same liquid4 ,a conv5i5t am\nt ( air is !n introduc$ into ! tube & its volume accurately not$4 ,!re is !n introduc$ m ?an suffici5t hydrog5 to comb9e ) ! oxyg5 pres5t 9 ! inclos$ air1 & ! volume is aga9 accurately not$4 ,! mixture is !n explod$ by an electric sp>k1 & ! volume is once m tak54 ,by subtract+ ?is volume f ! total volume ( ! air & hydrog5 !re is obta9$ ! contraction 9 volume due to ! union ( ! oxyg5 & hydrog54 ,! volume occupi$ by ! wat] =m$ by ! union ( ! two gases is s small t x may be disreg>d$ 9 ! calculation4 ,s9ce oxyg5 & hydrog5 comb9e 9 ! ratio #a3 #b by volume1 x is evid5t t ! contraction 9 volume due to ! comb9ation is equal to ! volume occupi$ by ! oxyg5 9 ! air conta9$ 9 ! tube1 plus twice ?is volume ( hydrog54 ,9 o!r words1 "o ?ird ( ! total contraction is equal to ! volume occupi$ by ! oxyg5 9 ! inclos$ air4 ,! foll[+ example w make ?is cle>3 ,volume ( air 9 tube #ej4j cc4 ,volume aft] introduc+ hydrog5 #hj4j ,volume aft] comb9ation ( oxyg5 & hydrog5 #dh4e ,contraction 9 volume due to comb9ation 7#hj cc4-#dh4e cc47 #ca4e ,volume ( oxyg5 9 #ej cc4 ( air 7#a_/c ( #ca4e7 #aj4e ,all ^! me?ods agree 9 %[+ t #ajj volumes ( dry air conta9 approximately #ba volumes ( oxyg54 #b4 ,det]m9ation ( nitrog54 ,if ! gas left aft] ! removal ( oxyg5 f a portion ( air is pass$ ov] heat$ magnesium1 ! nitrog5 is )drawn1 argon & ! o!r r>e elem5ts be+ left4 ,x may ?us be %[n t ( ! #gi volumes ( gas left aft] ! removal ( ! oxyg5 f #ajj volumes ( air1 approximately #gh are nitrog5 & #j4ic argon4 ,! o!r elem5ts are pres5t 9 su* small quantities t !y may be neglect$4 #c4 ,det]m9ation ( c>bon dioxide4 ,! p]c5tage ( c>bon dioxide 9 any giv5 volume ( air may be det]m9$ by pass+ ! air ov] calcium hydroxide or "s o!r comp\nd :i* w comb9e ) ! c>bon dioxide4 ,! increase 9 ! weight ( ! hydroxide equals ! weight ( ! c>bon dioxide absorb$4 ,! am\nt pres5t 9 ! op5 normal air is f #c to #d p>ts by volume 9 #aj1jjj volumes ( air1 or ab\t #j4jd4 #d4 ,det]m9ation ( wat] vapor4 ,! wat] vapor pres5t 9 a giv5 volume ( air may be det]m9$ by pass+ ! air ov] calcium *loride 7or "s o!r comp\nd :i* has a /rong aff9ity = wat]71 & not+ ! increase 9 ! weight ( ! *loride4 ,! am\nt pres5t v>ies n only ) ! locality1 b !re is a wide v>iation f day to day 9 ! same locality because ( ! w9ds & *anges 9 temp]ature4 ,processes affect+ ! composition ( ! air4 ,! mo/ important ( ^! processes are ! foll[+4 #a4 ,respiration4 ,9 ! process ( respiration "s ( ! oxyg5 9 ! inhal$ air is absorb$ by ! blood & c>ri$ to all p>ts ( ! body1 :]e x comb9es ) ! c>bon ( ! worn-out tissues4 ,! products ( oxidation are c>ri$ back to ! lungs & exhal$ 9 ! =m ( c>bon dioxide4 ,! am\nt exhal$ by an adult av]ages ab\t #bj l4 p] h\r4 ,h5ce 9 a poorly v5tilat$ room occupi$ by a numb] ( p ! am\nt ( c>bon dioxide rapidly increases4 ,:ile ?is gas is n poison\s unless pres5t 9 l>ge am\nts1 nev]!less air conta9+ m ?an #ae p>ts 9 #aj1jjj is n fit = respiration4 #b4 ,combu/ion4 ,all ( ! ord9>y =ms ( fuel conta9 l>ge p]c5tages ( c>bon4 ,on burn+1 ?is c>bon comb9es ) oxyg5 9 ! air1 =m+ c>bon dioxide4 ,combu/ion & respiration1 !re=e1 t5d to dim9i% ! am\nt ( oxyg5 9 ! air & to increase ! am\nt ( c>bon dioxide4 #c4 ,action ( plants4 ,plants h ! p[]1 :5 9 ! sunlight1 ( absorb+ c>bon dioxide f ! air1 reta9+ ! c>bon & return+ at lea/ a portion ( ! oxyg5 to ! air4 ,x w be obs]v$ t ^! *anges are j ! opposite ( ^? br\ght ab\t by ! processes ( respiration & combu/ion4 ,poison\s effect ( exhal$ air4 ,! diff]5ces 9 ! p]c5tages ( oxyg51 c>bon dioxide1 & moi/ure pres5t 9 inhal$ air & exhal$ air are %[n 9 ! foll[+ analyses4 ,,inhal$ ,,air ,,exhal$ ,,air ,oxyg5 #ba4jj #af4jj ,c>bon dioxide #j4jd #d4ch ,moi/ure v>iable saturat$ ,! f\l odor ( respir$ air is due to ! pres5ce ( a c]ta9 am\nt ( organic matt]4 ,x is possible t ?is organic matt] r ?an ! c>bon dioxide is responsible = ! injuri\s effects :i* foll[ ! respiration ( impure air4 ,! ext5t ( su* organic impurities pres5t may be judg$1 h[ev]1 by ! am\nt ( c>bon dioxide pres5t1 s9ce ! two are exhal$ toge!r4 ,! cycle ( c>bon 9 nature4 ,"u ! influ5ce ( sunlight1 ! c>bon dioxide absorb$ f ! air by plants reacts ) wat] & small am\nts ( o!r sub/ances absorb$ f ! soil to =m complex comp\nds ( c>bon :i* con/itute ! ess5tial "p ( ! plant tissue4 ,?is reaction is att5d$ by ! evolution ( oxyg51 :i* is re/or$ to ! air4 ,! comp\nds result+ f ^! *anges are mu* ri*] 9 _! en]gy cont5t ?an are ! sub/ances f :i* !y are =m$2 h5ce a c]ta9 am\nt ( en]gy mu/ h be5 absorb$ 9 _! =mation4 ,! s\rce ( ?is en]gy is ! sun's rays4 ,if ! plant is burn$1 ! *anges :i* took place 9 ! =mation ( ! comp\nds pres5t are l>gely rev]s$4 ,! c>bon & hydrog5 pres5t comb9e ) oxyg5 tak5 f ! air to =m c>bon dioxide & wat]1 :ile ! en]gy absorb$ f ! sun's rays is lib]at$ 9 ! =m ( en]gy ( heat4 ,if1 on ! o!r h&1 ! plant is us$ z food1 ! comp\nds pres5t are us$ 9 build+ up ! tissues ( ! body4 ,:5 ?is tissue breaks d[n1 ! *anges :i* x und]goes are v simil> to ^? :i* take place :5 ! plant is burn$4 ,! c>bon & hydrog5 comb9e ) ! inhal$ oxyg5 to =m c>bon dioxide & wat]1 :i* are exhal$4 ,! en]gy possess$ by ! complex sub/ances is lib]at$ p>tly 9 ! =m ( en]gy ( heat1 :i* ma9ta9s ! heat ( ! body1 & p>tly 9 ! v>i\s =ms ( muscul> en]gy4 ,! c>bon orig9ally absorb$ f ! air by ! plant 9 ! =m ( c>bon dioxide is ?us re/or$ to ! air & is ready to repeat ! cycle ( *anges4 ,! composition ( ! air is con/ant4 ,not)/&+ ! *anges con/antly tak+ place :i* t5d to alt] ! composition ( ! air1 ! results ( a great _m analyses ( air collect$ 9 ! op5 fields %[ t ! p]c5tages ( oxyg5 & nitrog5 z well z ( c>bon dioxide are v ne>ly con/ant4 ,inde$1 s con/ant are ! p]c5tages ( oxyg5 & nitrog5 t ! "q has aris51 :e!r ^! two elem5ts are n comb9$ 9 ! air1 =m+ a def9ite *emical comp\nd4 ,t ! two are n comb9$ b are simply mix$ toge!r c be %[n 9 a numb] ( ways1 among :i* are ! foll[+4 #a4 ,:5 air dissolves 9 wat] x has be5 f\nd t ! ratio ( oxyg5 to nitrog5 9 ! dissolv$ air is no long] #ba3 #gh1 b m ne>ly #ce3 #fe4 ,if x 7 a *emical comp\nd1 ! ratio ( oxyg5 to nitrog5 w\ld n be *ang$ by solution 9 wat]4 #b4 ,a *emical comp\nd 9 ! =m ( a liquid has a def9ite boil+ po9t4 ,wat]1 = example1 boils at #ajj4 ,moreov] ! /eam :i* is ?us =m$ has ! same composition z ! wat]4 ,! boil+ po9t ( liquid air1 on ! o!r h&1 gradually rises z ! liquid boils1 ! nitrog5 escap+ fir/ foll[$ by ! oxyg54 ,if ! two 7 comb9$1 !y w\ld pass (f toge!r 9 ! ratio 9 :i* !y are f\nd 9 ! air4 ,:y ! air has a con/ant composition4 ,if air is a mixture & *anges are con/antly tak+ place :i* t5d to modify its composition1 h[1 !n1 d we acc\nt = ! con/ancy ( composition :i* ! analyses reveal8 ,?is is expla9$ by sev]al facts4 7#a7 ,! *anges :i* are caus$ by ! processes ( combu/ion & respiration1 on ! "o h&1 & ! action ( plants1 on ! o!r1 t5d to equalize ea* o!r4 7#b7 ,! w9ds keep ! air 9 con/ant motion & s prev5t local *anges4 7#c7 ,! volume ( ! air is s va/ & ! *anges :i* occur are s small comp>$ ) ! total am\nt ( air t !y _c be readily detect$4 7#d7 ,f9ally x mu/ be not$ t only air collect$ 9 ! op5 fields %[s ?is con/ancy 9 composition4 ,! air 9 a poorly v5tilat$ room occupi$ by a numb] ( p rapidly *anges 9 composition4 ,! prop]ties ( ! air4 ,inasmu* z air is compos$ pr9cipally ( a mixture ( oxyg5 & nitrog51 :i* elem5ts h already be5 discuss$1 its prop]ties may be inf]r$ l>gely f ^? ( ! two gases4 ,"o lit] weighs #a4bibc g4 ,x is ?us #ad4ch times z heavy z hydrog54 ,at ! sea level x ex]ts an av]age pressure suffici5t to su/a9 a column ( m]cury #gfj mm4 9 height4 ,?is is tak5 z ! /&>d pressure 9 det]m9+ ! volumes ( gases z well z ! boil+ po9ts ( liquids4 ,wat] may be made to boil at any temp]ature betwe5 #j & consid]ably above #ajj by simply v>y+ ! pressure4 ,x is only :5 ! pressure ^u x is equal to ! normal pressure ( ! atmosph]e at ! sea level1 z indicat$ by a b>ometric read+ ( #gfj mm41 t x boils at #ajj4 ,prep>ation ( liquid air4 ,att5tion has be5 call$ to ! fact t bo? oxyg5 & nitrog5 c be obta9$ 9 ! liquid /ate by /rongly cool+ ! gases & apply+ great pressure to !m4 ,s9ce air is l>gely a mixture ( ^! two gases1 x c be liquefi$ by ! same me?ods4 ,! me?ods = liquefy+ air h be5 simplifi$ greatly 9 t ! l[ temp]ature requir$ is obta9$ by all[+ a portion ( ! compress$ air to exp&4 ,! expansion ( a gas is always att5d$ by ! absorption ( heat4 ,9 liquefy+ air ! app>atus is s con/ruct$ t ! heat absorb$ is )drawn f air already "u great pressure4 ,?is process is cont9u$ until ! temp]ature is l[]$ to ! po9t ( liquefaction4 ,illu/ration3 ,fig4 #bi ,! ,dew> bulb4 ,x is n possible to pres]ve air 9 ! liquid /ate 9 a clos$ vessel1 on acc\nt ( ! enorm\s pressure ex]t$ by x 9 its t5d5cy to pass into ! gase\s /ate4 ,x may h[ev] be pres]v$ = "s h\rs or ev5 days be=e x w completely evaporate1 by simply plac+ x 9 an op5 vessel surr\nd$ by a nonconduct+ mat]ial4 ,! mo/ effici5t vessel = ?is purpose is ! ,dew> bulb %[n 9 ,fig4 #bi4 ,! air is )drawn f ! space betwe5 ! two walls1 ?us mak+ x nonconduct+4 ,prop]ties & uses ( liquid air4 ,:5 fir/ prep>$1 liquid air is cl\dy because ( ! pres5ce ( p>ticles ( solid c>bon dioxide4 ,^! may be filt]$ (f1 leav+ a liquid ( slightly blui% color4 ,x beg9s to boil at ab\t -#aij1 ! nitrog5 pass+ (f fir/1 gradually foll[$ by ! oxyg51 ! la/ portions be+ ne>ly pure oxyg54 ,to a c]ta9 ext5t oxyg5 is n[ prep>$ 9 ?is way = comm]cial purposes4 ,! extremely l[ temp]ature ( liquid air may be inf]r$ f ! fact t m]cury :5 cool$ by x is froz5 to a mass s h>d t x may be us$ = driv+ nails4 ,liquid air is us$ 9 ! prep>ation ( oxyg5 & z a cool+ ag5t 9 ! /udy ( ! prop]ties ( matt] at l[ temp]atures4 ,x has ?us be5 f\nd t elem5ts at extremely l[ temp]atures l>gely lose _! *emical activity4 ,,ex]cises #a4 ,:5 oxyg5 & nitrog5 are mix$ 9 ! proportion 9 :i* !y exi/ 9 ! atmosph]e1 heat is nei!r evolv$ nor absorb$ by ! process4 ,:at important po9t does ?is sugge/8 #b4 ,:at ess5tial con/itu5t ( ! air is f\nd 9 l>g] am\nt 9 manufactur+ di/ricts ?an 9 ! op5 c\ntry8 #c4 ,c y sugge/ any reason :y ! gr[? ( clov] 9 a field improves ! soil8 #d4 ,:y are ! inn] walls ( a ,dew> bulb sometimes coat$ ) a film ( silv]8 #e4 ,to :at is ! blue color ( liquid air due8 ,does ?is color increase 9 int5sity on /&+8 #f4 ,:5 ice is plac$ 9 a vessel conta9+ liquid air1 ! latt] boils viol5tly4 ,expla94 #g4 ,tak+ ! volumes ( ! oxyg5 & nitrog5 9 #ajj volumes ( air z #ba & #gh respectively1 calculate ! p]c5tages ( ^! elem5ts pres5t by weight4 #h4 ,w\ld combu/ion be m int5se 9 liquid air ?an 9 ! gase\s sub/ance8 #i4 ,a tube conta9+ calcium *loride 0 f\nd to weigh #cj4abic g4 ,a volume ( air :i* weigh$ #ae4bacd g4 0 pass$ ?r\gh1 aft] :i* ! weight ( ! tube 0 f\nd to be #cj4cdje g4 ,:at 0 ! p]c5tage am\nt ( moi/ure pres5t 9 ! air8 #aj4 #aj l4 ( air measur$ at #bj & #gdj mm4 pass$ ?r\gh lime wat] caus$ ! precipitation ( #j4jajb g4 ( ,ca,c,o#c4 ,f9d ! numb] ( volumes ( c>bon dioxide 9 #aj1jjj volumes ( ! air4 ,,*apt] ,,ix ,,solutions ,def9itions4 ,:5 a sub/ance disappe>s 9 a liquid 9 su* a way z to ?or\ghly mix ) x & to be lo/ to sight z an individual body1 ! result+ liquid is call$ a solution4 ,! liquid 9 :i* ! sub/ance dissolves is call$ ! solv5t1 :ile ! dissolv$ sub/ance is call$ ! solute4 ,classes ( solutions4 ,matt] 9 any "o ( its physical /ates may dissolve 9 a liquid1 s t we may h solutions ( gases1 ( liquids1 & ( solids4 ,solutions ( liquids 9 liquids are n (t5 m5tion$ 9 ! foll[+ pages1 b ! o!r two classes w become v famili> 9 ! c\rse ( our /udy1 & des]ve special att5tion4 ,,solution ,,( ,,gases ,,9 ,,liquids ,illu/ration3 ,fig4 #cj ,x has already be5 /at$ t oxyg51 hydrog51 & nitrog5 are slightly soluble 9 wat]4 ,accurate /udy has l$ to ! conclusion t all gases are soluble to "s ext5t n only 9 wat] b 9 _m o!r liquids4 ,! am\nt ( a gas :i* w dissolve 9 a liquid dep5ds ^u a numb] ( conditions1 & ^! c be/ be und]/ood by suppos+ a vessel ,b 7,fig4 #cj71 to be fill$ ) ! gas & inv]t$ ov] ! liquid4 ,"u ^! circum/ances ! gas _c escape or become mix$ ) ano!r gas4 ,circum/ances affect+ ! solubility ( gases4 ,a numb] ( circum/ances affect ! solubility ( a gas 9 a liquid4 #a4 ,nature ( ! gas4 ,o!r conditions be+ equal1 ea* gas has its own peculi> solubility1 j z x has its own special ta/e or odor4 ,! solubility ( gases v>ies betwe5 wide limits1 z w be se5 f ! foll[+ table1 b z a rule a giv5 volume ( a liquid w n dissolve m ?an two or ?ree times its own volume ( a gas4 ,solubility ( ,gases 9 ,wat] #a l4 ( wat] at #gfj mm4 pressure & at #j w dissolve3 ,ammonia #aadh4jj l4 ,hydro*loric acid #ejc4jj ,sulphur dioxide #gi4gi ,c>bon dioxide #a4hj ,oxyg5 #da4ad cc4 ,hydrog5 #ba4ae ,nitrog5 #bj4jc ,9 ! case ( v soluble gases1 su* z ! fir/ ?ree 9 ! table1 x is probable t *emical comb9ation betwe5 ! liquid & ! gas takes place4 #b4 ,nature ( ! liquid4 ,! "* ( ! liquid has mu* influ5ce ^u ! solubility ( a gas4 ,wat]1 alcohol1 & e!r h ea* its own peculi> solv5t p[]4 ,f ! solubility ( a gas 9 wat]1 no pr$iction c be made z to its solubility 9 o!r liquids4 #c4 ,influ5ce ( pressure4 ,x has be5 f\nd t ! weight ( gas :i* dissolves 9 a giv5 case is proportional to ! pressure ex]t$ ^u ! gas4 ,if ! pressure is d\bl$1 ! weight ( gas go+ into solution is d\bl$2 if ! pressure is dim9i%$ to "o half ( its orig9al value1 half ( ! dissolv$ gas w escape4 ,"u high pressure1 l>ge quantities ( gas c be dissolv$ 9 a liquid1 & :5 ! pressure is remov$ ! gas escapes1 caus+ ! liquid to foam or eff]vesce4 #d4 ,influ5ce ( temp]ature4 ,9 g5]al1 ! l[] ! temp]ature ( ! liquid1 ! l>g] ! quantity ( gas :i* x c dissolve4 #ajjj volumes ( wat] at #j w dissolve #da4ad volumes ( oxyg52 at #ej1 #ah4cg volumes2 at #ajj none at all4 ,:ile mo/ gases c be expell$ f a liquid by boil+ ! solution1 "s _c4 ,= example1 x is n possible to expel hydro*loric acid gas completely f its solution by boil+4 ,,solution ,,( ,,solids ,,9 ,,liquids ,?is is ! mo/ famili> class ( solutions1 s9ce 9 ! laboratory sub/ances are mu* m frequ5tly us$ 9 ! =m ( solutions ?an 9 ! solid /ate4 ,circum/ances affect+ ! solubility ( a solid4 ,! solubility ( a solid 9 a liquid dep5ds ^u sev]al factors4 #a4 ,nature ( ! solid4 ,o!r conditions be+ ! same1 solids v>y greatly 9 _! solubility 9 liquids4 ,?is is illu/rat$ 9 ! foll[+ table3 ,table ( ,solubility ( ,solids at #ah #ajj cc4 ( wat] w dissolve3 ,calcium *loride #ga4j g4 ,sodium *loride #ce4i ,potassium nitrate #bi4a ,copp] sulphate #ba4d ,calcium sulphate #j4bjg ,no solids are absolutely insoluble1 b ! am\nt dissolv$ may be s small z to be ( no significance = mo/ purposes4 ,?us b>ium sulphate1 "o ( ! mo/ insoluble ( common sub/ances1 dissolves 9 wat] to ! ext5t ( #a "p 9 #djj1jjj4 #b4 ,nature ( ! solv5t4 ,liquids v>y mu* 9 _! p[] to dissolve solids4 ,"s are said to be good solv5ts1 s9ce !y dissolve a great v>iety ( sub/ances & consid]able quantities ( !m4 ,o!rs h small solv5t p[]1 dissolv+ few sub/ances1 & ^? to a slight ext5t only4 ,broadly speak+1 wat] is ! mo/ g5]al solv5t1 & alcohol is p]haps second 9 solv5t p[]4 #c4 ,temp]ature4 ,! weight ( a solid :i* a giv5 liquid c dissolve v>ies ) ! temp]ature4 ,usually x increases rapidly z ! temp]ature rises1 s t ! boil+ liquid dissolves sev]al times ! weight :i* ! cold liquid w dissolve4 ,9 "s in/ances1 z 9 ! case ( common salt dissolv$ 9 wat]1 ! temp]ature has little influ5ce ^u ! solubility1 & a few solids are m soluble 9 cold wat] ?an 9 hot4 ,! foll[+ examples w s]ve z illu/rations3 ,table ( ,solubility at #j & at #ajj #ajj cc4 ( wat] w dissolve3 ,at #j ,at #ajj ,calcium *loride #di4f g4 #aee4j g4 ,sodium *loride #ce4g #ci4h ,potassium nitrate #ac4c #bdg4j ,copp] sulphate #ae4e #gc4e ,calcium sulphate #j4bje #j4bag ,calcium hydroxide #j4agc #j4jgi ,saturat$ solutions4 ,a liquid w n dissolve an unlimit$ quantity ( a solid4 ,on add+ ! solid to ! liquid 9 small portions at a "t1 x w be f\nd t a po9t is rea*$ at :i* ! liquid w n dissolve m ( ! solid at t temp]ature4 ,! solid & ! solution rema9 9 contact ) ea* o!r un*ang$4 ,?is condition may be describ$ by say+ t !y are 9 equilibrium ) ea* o!r4 ,a solution is said to be saturat$ :5 x rema9s un*ang$ 9 conc5tration 9 contact ) "s ( ! solid4 ,! weight ( ! solid :i* w completely saturate a def9ite volume ( a liquid at a giv5 temp]ature is call$ ! solubility ( ! sub/ance at t temp]ature4 ,sup]saturat$ solutions4 ,:5 a solution1 saturat$ at a giv5 temp]ature1 is all[$ to cool x sometimes happ5s t no solid cry/allizes out4 ,?is is v likely to occur :5 ! vessel us$ is p]fectly smoo? & ! solution is n di/urb$ 9 any way4 ,su* a solution is said to be sup]saturat$4 ,t ?is condition is un/able c be %[n by add+ a cry/al ( ! solid to ! solution4 ,all ( ! solid 9 excess ( ! quantity requir$ to saturate ! solution at ?is temp]ature w at once cry/allize out1 leav+ ! solution saturat$4 ,sup]saturation may also be ov]come 9 _m cases by vigor\sly %ak+ or /irr+ ! solution4 ,g5]al physical prop]ties ( solutions4 ,a few g5]al /atem5ts may be made 9 ref]5ce to ! physical prop]ties ( solutions4 #a4 ,di/ribution ( ! solid 9 ! liquid4 ,a solid1 :5 dissolv$1 t5ds to di/ribute itself uni=mly ?r\gh ! liquid1 s t e "p ( ! solution has ! same conc5tration4 ,! process goes on v sl[ly unless ha/5$ by /irr+ or %ak+ ! solution4 ,?us1 if a few cry/als ( a highly color$ sub/ance su* z copp] sulphate are plac$ 9 ! bottom ( a tall vessel full ( wat]1 x w take weeks = ! solution to become uni=mly color$4 #b4 ,boil+ po9ts ( solutions4 ,! boil+ po9t ( a liquid is rais$ by ! pres5ce ( a sub/ance dissolv$ 9 x4 ,9 g5]al ! ext5t to :i* ! boil+ po9t ( a solv5t is rais$ by a giv5 sub/ance is proportional to ! conc5tration ( ! solution1 t is1 to ! weight ( ! sub/ance dissolv$ 9 a def9ite weight ( ! solv5t4 #c4 ,freez+ po9ts ( solutions4 ,a solution freezes at a l[] temp]ature ?an ! pure solv5t4 ,! l[]+ ( ! freez+ po9t obeys ! same law :i* holds = ! rais+ ( ! boil+ po9t3 ! ext5t ( l[]+ is proportional to ! weight ( dissolv$ sub/ance1 t is1 to ! conc5tration ( ! solution4 ,electrolysis ( solutions4 ,pure wat] does n appreciably conduct ! electric curr5t4 ,if1 h[ev]1 c]ta9 sub/ances su* z common salt are dissolv$ 9 ! wat]1 ! result+ solutions are f\nd to be conductors ( electricity4 ,su* solutions are call$ electrolytes4 ,:5 ! curr5t passes ?r\gh an electrolyte "s *emical *ange always takes place4 ,?is *ange is call$ electrolysis4 ,illu/ration3 ,fig4 #ca ,! g5]al me?od us$ 9 ! electrolysis ( a solution is illu/rat$ 9 ,fig4 #ca4 ,! vessel ,d conta9s ! electrolyte4 ,two plates or rods1 ,a & ,b1 made ( suitable mat]ial1 are connect$ ) ! wires f a batt]y 7or dynamo7 & dipp$ into ! electrolyte1 z %[n 9 ! figure4 ,^! plates or rods are call$ electrodes4 ,! electrode connect$ ) ! z9c plate ( ! batt]y is ! negative electrode or ca?ode1 :ile t connect$ ) ! c>bon plate is ! positive electrode or anode4 ,!ory ( electrolytic dissociation4 ,! facts :i* h j be5 describ$ 9 connection ) solutions1 toge!r ) _m o!rs1 h l$ *emi/s to adopt a !ory ( solutions call$ ! !ory ( electrolytic dissociation4 ,! ma9 assumptions 9 ?is !ory are ! foll[+4 #a4 ,=mation ( ions4 ,_m comp\nds :5 dissolv$ 9 wat] und]go an important *ange4 ,a portion ( _! molecules fall ap>t1 or dissociate1 into two or m p>ts1 call$ ions4 ,?us sodium nitrate 7,na,n,o#c7 dissociates into ! ions ,na & ,,no#c2 sodium *loride1 into ! ions ,na & ,cl4 ,^! ions are free to move ab\t 9 ! solution indep5d5tly ( ea* o!r l indep5d5t molecules1 & = ?is reason 7 giv5 ! "n ion1 :i* signifies a w&]]4 #b4 ,! electrical *>ge ( ions4 ,ea* ion c>ries a heavy electrical *>ge1 & 9 ?is respect diff]s f an atom or molecule4 ,x is evid5t t ! sodium 9 ! =m ( an ion mu/ diff] 9 "s important way f ord9>y sodium1 = sodium ions1 =m$ f sodium nitrate1 give no visible evid5ce ( _! pres5ce 9 wat]1 :]eas metallic sodium at once decomposes ! wat]4 ,! electrical *>ge1 !re=e1 greatly modifies ! usual *emical prop]ties ( ! elem5t4 #c4 ,! positive *>ges equal ! negative *>ges4 ,! ions =m$ by ! dissociation ( any molecule are ( two k9ds4 ,"o k9d is *>g$ ) positive electricity & ! o!r ) negative electricity2 moreov] ! sum ( all ! positive *>ges is always equal to ! sum ( all ! negative *>ges4 ,! solution z a :ole is !re=e electrically neutral4 ,if we repres5t dissociation by ! usual *emical equations1 ) ! electrical *>ges indicat$ by & - signs foll[+ ! symbols1 ! dissociation ( sodium *loride molecules is repres5t$ ?us3 ,na,cl -- ,na1 ,cl-4 ,! positive *>ge on ea* sodium ion exactly equals ! negative *>ge on ea* *lor9e ion4 ,sodium sulphate dissociates1 z %[n 9 ! equation ,na#b,,s#d -- #b,na1 ,,s#d--4 ,"h ! positive *>ge on ! two sodium ions equals ! d\ble negative *>ge on ! ,,s#d ion4 #d4 ,n all comp\nds dissociate4 ,only ^? comp\nds dissociate ^: solutions =m electrolytes4 ,?us salt dissociates :5 dissolv$ 9 wat]1 ! result+ solution be+ an electrolyte4 ,sug>1 on ! o!r h&1 does n dissociate & its solution is n a conductor ( ! electric curr5t4 #e4 ,ext5t ( dissociation diff]s 9 diff]5t liquids4 ,:ile comp\nds mo/ readily und]go dissociation 9 wat]1 yet dissociation (t5 occurs to a limit$ ext5t :5 solution takes place 9 liquids o!r ?an wat]4 ,9 ! discussion ( solutions x w be und]/ood t ! solv5t is wat] unless o!rwise not$4 ,! !ory ( electrolytic dissociation & ! prop]ties ( solutions4 ,9 ord] to be ( value1 ?is !ory mu/ give a reasonable explanation ( ! prop]ties ( solutions4 ,let u n[ see if ! !ory is 9 h>mony ) c]ta9 ( ^! prop]ties4 ,! !ory ( electrolytic dissociation & ! boil+ & freez+ po9ts ( solutions4 ,we h se5 t ! boil+ po9t ( a solution ( a sub/ance is rais$ 9 proportion to ! conc5tration ( ! dissolv$ sub/ance4 ,?is is b ano!r way ( say+ t ! *ange 9 ! boil+ po9t ( ! solution is proportional to ! numb] ( molecules ( ! dissolv$ sub/ance pres5t 9 ! solution4 ,x has be5 f\nd1 h[ev]1 t 9 ! case ( electrolytes ! boil+ po9t is rais$ m ?an x %\ld be to con=m to ?is law4 ,if ! solute dissociates into ions1 ! reason = ?is becomes cle>4 ,ea* ion has ! same effect on ! boil+ po9t z a molecule1 & s9ce _! numb] is great] ?an ! numb] ( molecules f :i* !y 7 =m$1 ! effect on ! boil+ po9t is abnormally great4 ,9 a simil> way1 ! !ory furni%es an explanation ( ! abnormal l[]+ ( ! freez+ po9t ( electrolytes4 ,! !ory ( electrolytic dissociation & electrolysis4 ,! *anges tak+ place dur+ electrolysis h>monize v completely ) ! !ory ( dissociation4 ,?is w become cle> f a /udy ( ! foll[+ examples4 ,illu/ration3 ,fig4 #cb #a4 ,electrolysis ( sodium *loride4 ,fig4 #cb repres5ts a vessel 9 :i* ! electrolyte is a solution ( sodium *loride 7,na,cl74 ,accord+ to ! dissociation !ory ! molecules ( sodium *loride dissociate into ! ions ,na & ,cl-4 ,! ,na ions are attract$ to ! ca?ode ow+ to its l>ge negative *>ge4 ,on com+ into contact ) ! ca?ode1 ! ,na ions give up _! positive *>ge & are !n ord9>y sodium atoms4 ,!y imm$iately decompose ! wat] accord+ to ! equation ,na ,h#b,o ,na,o,h ,h1 & hydrog5 is evolv$ ab\t ! ca?ode4 ,! *lor9e ions on be+ dis*>g$ at ! anode 9 simil> mann] may ei!r be giv5 (f z *lor9e gas1 or may attack ! wat]1 z repres5t$ 9 ! equation #b;,cl ,h#b,o #b;,h,cl ,o4 #b4 ,electrolysis ( wat]4 ,! reason = ! addition ( sulphuric acid to wat] 9 ! prep>ation ( oxyg5 & hydrog5 by electrolysis w n[ be cle>4 ,wat] itself is n an electrolyte to an appreciable ext5t2 t is1 x does n =m en\gh ions to c>ry a curr5t4 ,sulphuric acid dissolv$ 9 wat] is an electrolyte1 & dissociates into ! ions #b ,h & ,,s#d--4 ,9 ! process ( electrolysis ( ! solution1 ! hydrog5 ions travel to ! ca?ode1 & on be+ dis*>g$ escape z hydrog5 gas4 ,! ,,s#d ions1 :5 dis*>g$ at ! anode1 act ^u wat]1 sett+ free oxyg5 & once m =m+ sulphuric acid3 ,,s#d ,h#b,o ,h#b,,s#d ,o4 ,! sulphuric acid c aga9 dissociate & ! process repeat itself z long z any wat] is left4 ,h5ce ! hydrog5 & oxyg5 set free 9 ! electrolysis ( wat] really come directly f ! acid b indirectly f ! wat]4 #c4 ,electrolysis ( sodium sulphate4 ,9 a simil> way1 sodium sulphate 7,na#b,,s#d71 :5 9 solution1 gives ! ions #b ,na & ,,s#d--4 ,on be+ dis*>g$1 ! sodium atoms decompose wat] ab\t ! ca?ode1 z 9 ! case ( sodium *loride1 :ile ! ,,s#d ions :5 dis*>g$ at ! anode decompose ! wat]1 z repres5t$ 9 ! equation ,,s#d ,h#b,o ,h#b,,s#d ,o ,illu/ration3 ,fig4 #cc ,t new sub/ances are =m$ at ! ca?ode & anode may be %[n 9 ! foll[+ way4 ,a ,u-tube1 su* z is repres5t$ 9 ,fig4 #cc1 is p>tially fill$ ) a solution ( sodium sulphate1 & ! liquid 9 "o arm is color$ ) r$ litmus1 t 9 ! o!r ) blue litmus4 ,an electrode plac$ 9 ! r$ solution is made to s]ve z ca?ode1 :ile "o 9 ! blue solution is made ! anode4 ,on all[+ ! curr5t to pass1 ! blue solution turns r$1 :ile ! r$ solution turns blue4 ,^! are exactly ! *anges :i* w\ld take place if sodium hydroxide & sulphuric acid 7 to be set free at ! electrodes1 z requir$ by ! !ory4 ,! prop]ties ( electrolytes dep5d ^u ! ions pres5t4 ,:5 a sub/ance capable ( dissociat+ into ions is dissolv$ 9 wat]1 ! prop]ties ( ! solution w dep5d ^u two factors3 7#a7 ! ions =m$ f ! sub/ance2 7#b7 ! undissociat$ molecules4 ,s9ce ! ions are usually m active *emically ?an ! molecules1 mo/ ( ! *emical prop]ties ( an electrolyte are due to ! ions r ?an to ! molecules4 ,! solutions ( any two sub/ances :i* give ! same ion w h c]ta9 prop]ties 9 common4 ,?us all solutions conta9+ ! copp] ion 7,cu7 are blue1 unless ! color is modifi$ by ! pres5ce ( ions or molecules hav+ "s o!r color4 ,,ex]cises #a4 ,di/+ui% cle>ly betwe5 ! foll[+ t]ms3 electrolysis1 electrolyte1 electrolytic dissociation1 ions1 solute1 solv5t1 solution1 saturat$ solution1 & sup]saturat$ solution4 #b4 ,:y does ! wat] f "s natural spr+s eff]vesce8 #c4 7a7 ,:y does n ! wat] ( ! ocean freeze8 7b7 ,:y w ice & salt produce a l[] temp]ature ?an ice alone8 #d4 ,:y does %ak+ or /irr+ make a solid dissolve m rapidly 9 a liquid8 #e4 ,by exp]im5t x 0 f\nd t a c]ta9 volume ( wat] 0 saturat$ at #ajj ) #aad g4 ( potassium nitrate4 ,on cool+ to #j a portion ( ! sub/ance cry/alliz$4 7a7 ,h[ _m grams ( ! sub/ance rema9$ 9 solution8 7b7 ,:at 0 ! /r5g? ( ! solution at #ah8 7c7 ,h[ mu* wat] _h be5 us$ 9 ! exp]im5t8 #f4 7a7 #aj g4 ( common salt 7 dissolv$ 9 wat] & ! solution evaporat$ to dryness2 :at weight ( solid 0 left8 7b7 #aj g4 ( z9c 7 dissolv$ 9 hydro*loric acid & ! solution evaporat$ to dryness2 :at weight ( solid 0 left8 #g4 ,acc\nt = ! fact t sug> sometimes deposits f molasses1 ev5 :5 no evaporation has tak5 place4 #h4 7a7 ,f ! /&po9t ( ! !ory ( electrolytic dissociation1 write ! simple equation = a dilute solution ( copp] sulphate 7,cu,s,o#d72 ?is solution is blue4 7b7 ,9 ! same mann]1 write "o = sodium sulphate2 ?is solution is colorless4 7c7 ,h[ w\ld y acc\nt = ! color ( ! copp] sulphate solution8 #i4 7a7 ,z 9 ! prec$+ ex]cise1 write a simple equation = a dilute solution ( copp] *loride 7,cu,cl#b72 ?is solution is blue4 7b7 ,9 ! same mann]1 write "o = sodium *loride2 ?is solution is colorless4 ,to :at is ! blue color due8 #aj4 ,:at compon5t is pres5t 9 conc5trat$ sulphuric acid t is almo/ want+ 9 v dilute sulphuric acid8 #aa4 ,:y w vegetables cook fa/] :5 boil$ 9 /rong salt wat] ?an :5 boil$ 9 pure wat]8 #ab4 ,h[ d y expla9 ! foam+ ( soda wat]8 ,,*apt] ,x ,,acids1 ,,bases1 ,,& ,,salts2 ,,neutralization ,acids1 bases1 & salts4 ,! ?ree classes ( comp\nds kn[n respectively z acids1 bases1 & salts include ! great majority ( ! comp\nds ) :i* we %all h to deal4 ,x is important1 !re=e1 = u to consid] ea* ( ^! classes 9 a sy/ematic way4 ,! individual memb]s belong+ to ea* class w be discuss$ 9 detail 9 ! appropriate places1 b a few repres5tatives ( ea* class w be describ$ 9 ?is *apt] ) special ref]5ce to ! common prop]ties 9 accordance ) :i* !y are classifi$4 ,! famili> acids4 ,hydro*loric acid is a gas compos$ ( hydrog5 & *lor9e1 & has ! =mula ,h,cl4 ,! sub/ance is v soluble 9 wat]1 & x is ?is solution :i* is usually call$ hydro*loric acid4 ,nitric acid is a liquid compos$ ( hydrog51 nitrog51 & oxyg51 hav+ ! =mula ,,hno#c4 ,z sold comm]cially x is mix$ ) ab\t #cb ( wat]4 ,sulphuric acid1 ^: composition is repres5t$ by ! =mula ,h#b,,s#d1 is an oily liquid ne>ly twice z heavy z wat]1 & is commonly call$ oil ( vitriol4 ,*>act]i/ics ( acids4 7#a7 ,all acids conta9 hydrog54 7#b7 ,:5 dissolv$ 9 wat] ! molecules ( ! acid dissociate into two k9ds ( ions4 ,"o ( ^! is always hydrog5 & is ! cation 771 :ile ! o!r consi/s ( ! rema9d] ( ! molecule & is ! anion 7-74 7#c7 ,! solution ta/es s\r4 7#d7 ,x has ! p[] to *ange ! color ( c]ta9 sub/ances call$ indicators4 ,?us blue litmus is *ang$ to r$1 & yell[ me?yl orange is *ang$ to r$4 ,s9ce all acids produce hydrog5 cations1 :ile ! anions ( ea* are diff]5t1 ! prop]ties :i* all acids h 9 common :5 9 solution1 su* z ta/e & action on indicators1 mu/ be attribut$ to ! hydrog5 ions4 ,,def9ition3 ,an acid is a sub/ance :i* produces hydrog5 ions :5 dissolv$ 9 wat] or o!r dissociat+ liquids4 ,undissociat$ acids4 ,:5 acids are p]fectly free f wat]1 or are dissolv$ 9 liquids l b5z5e :i* d n h ! p[] ( dissociat+ !m into ions1 !y %\ld h no real acid prop]ties4 ,?is is f\nd to be ! case4 ,"u ^! circum/ances !y d n affect ! color ( indicators or h any ( ! prop]ties *>act]i/ic ( acids4 ,! famili> bases4 ,! bases mo/ us$ 9 ! laboratory are sodium hydroxide 7,na,o,h71 potassium hydroxide 7,,koh71 & calcium hydroxide 7,ca7,,oh7#b74 ,^! are :ite solids1 soluble 9 wat]1 ! latt] sp>+ly s4 ,"s bases are v difficultly soluble 9 wat]4 ,! v soluble ones ) mo/ pron\nc$ basic prop]ties are sometimes call$ ! alkalis4 ,*>act]i/ics ( bases4 7#a7 ,all bases conta9 hydrog5 & oxyg54 7#b7 ,:5 dissolv$ 9 wat] ! molecules ( ! base dissociate into two k9ds ( ions4 ,"o ( ^! is always compos$ ( oxyg5 & hydrog5 & is ! anion4 ,x has ! =mula ,,oh & is call$ ! hydroxyl ion4 ,! rema9d] ( ! molecule1 :i* usually consi/s ( a s+le atom1 is ! cation4 7#c7 ,! solution ( a base has a soapy feel & a bracki% ta/e4 7#d7 ,x rev]ses ! color *ange produc$ 9 indicators by acids1 turn+ r$ litmus blue1 & r$ me?yl orange yell[4 ,s9ce all bases produce hydroxyl anions1 :ile ! cations ( ea* are diff]5t1 ! prop]ties :i* all bases h 9 common :5 9 solution mu/ be due to ! hydroxyl ions4 ,,def9ition3 ,a base is a sub/ance :i* produces hydroxyl ions :5 dissolv$ 9 wat] or o!r dissociat+ liquids4 ,undissociat$ bases4 ,bases1 9 ! abs5ce ( wat] or :5 dissolv$ 9 liquids :i* d n dissociate !m1 %\ld h none ( ! prop]ties *>act]i/ic ( ?is class ( sub/ances4 ,?is has be5 f\nd to be ! case4 ,= example1 !y h no effect ^u indicators "u ^! circum/ances4 ,neutralization4 ,:5 an acid & a base are br\ght toge!r 9 solution 9 prop] proportion1 ! *>act]i/ic prop]ties ( ea* disappe>4 ,! solution ta/es nei!r s\r nor bracki%2 x has no effect ^u indicators4 ,!re c !re=e be nei!r hydrog5 nor hydroxyl ions pres5t 9 ! solution4 ,a /udy ( reactions ( ?is k9d has %[n t ! hydrog5 ions ( ! acid comb9e ) ! hydroxyl ions ( ! base to =m molecules ( wat]1 wat] be+ a sub/ance :i* is n appreciably dissociat$ into ions4 ,?is action ( an acid on a base is call$ neutralization4 ,! foll[+ equations express ! neutralization ( ! ?ree acids by ?ree bases1 wat] be+ =m$ 9 ea* case4 ,na1 ,,oh- ,h1 ,cl- ,na1 ,cl- ,h#b,o4 ,k1 ,,oh- ,h1 ,,no#c- ,k1 ,,no#c- ,h#b,o4 ,ca1 7,,oh7#b-- ,h#b1 ,,s#d-- ,ca1 ,,s#d-- #b;,h#b,o4 ,,def9ition3 ,neutralization consi/s 9 ! union ( ! hydrog5 ion ( an acid ) ! hydroxyl ion ( a base to =m wat]4 ,salts4 ,x w be notic$ t 9 neutralization ! anion ( ! acid & ! cation ( ! base are n *ang$4 ,if1 h[ev]1 ! wat] is expell$ by evaporation1 ^! two ions sl[ly unite1 & :5 ! wat] becomes saturat$ ) ! sub/ance s produc$1 x sep>ates 9 ! =m ( a solid call$ a salt4 ,,def9ition3 ,a salt is a sub/ance =m$ by ! union ( ! anion ( an acid ) ! cation ( a base4 ,*>act]i/ics ( salts4 7#a7 ,f ! def9ition ( a salt x w be se5 t !re is no elem5t or gr\p ( elem5ts :i* *>act]ize salts4 7#b7 ,salts z a class h no peculi> ta/e4 7#c7 ,9 ! abs5ce ( all o!r sub/ances !y are )\t action on indicators4 7#d7 ,:5 dissolv$ 9 wat] !y =m two k9ds ( ions4 ,heat ( neutralization4 ,if neutralization is due to ! union ( hydrog5 ions ) hydroxyl ions1 & no?+ m1 x foll[s t :5 a giv5 weight ( wat] is =m$ 9 neutralization1 ! heat set free %\ld always be ! same1 no matt] f :at acid & base ! two k9ds ( ions h be5 suppli$4 ,c>eful exp]im5ts h %[n t ?is is ! case1 provid$ no o!r reactions take place at ! same "t4 ,:5 #ah;g4 ( wat] are =m$ 9 neutralization1 #ac1gjj cal4 ( heat are set free4 ,?is is repres5t$ 9 ! equations ,na1 ,,oh- ,h1 ,cl- ,na1 ,cl- ,h#b,o #ac1gjj cal4 ,k1 ,,oh- ,h1 ,,no#c- ,k1 ,,no#c- ,h#b,o #ac1gjj cal4 ,ca1 7,,oh7#b-- ,h#b1 ,,s#d-- ,ca1 ,,s#d-- #b;,h#b,o #b #ac1gjj cal4 ,neutralization a quantitative act4 ,s9ce neutralization is a def9ite *emical act1 ea* acid w require a p]fectly def9ite weight ( ea* base = its neutralization4 ,= example1 a giv5 weight ( sulphuric acid w always require a def9ite weight ( sodium hydroxide1 9 accordance ) ! equation ,h#b1 ,,s#d #b,na1 ,,oh ,na#b1 ,,s#d #b;,h#b,o4 ,det]m9ation ( ! ratio 9 neutralization4 ,! quantities ( acid & base requir$ 9 neutralization may be det]m9$ 9 ! foll[+ way4 ,dilute solutions ( ! two sub/ances are prep>$1 ! sulphuric acid be+ plac$ 9 "o ( ! burettes 7,fig4 #cd7 & ! sodium hydroxide 9 ! o!r4 ,! levels ( ! two liquids are !n br\ght to ! z]o m>ks ( ! burettes by means ( ! /opcocks4 ,a measur$ volume ( ! acid is drawn (f into a beak]1 a few drops ( litmus solution add$1 & ! sodium hydroxide is run 9 drop by drop until ! r$ litmus j turns blue4 ,! volume ( ! sodium hydroxide consum$ is !n not$4 ,if ! conc5trations ( ! two solutions are kn[n1 x is easy to calculate :at weight ( sodium hydroxide is requir$ to neutralize a giv5 weight ( sulphuric acid4 ,by evaporat+ ! neutraliz$ solution to dryness1 ! weight ( ! sodium sulphate =m$ c be det]m9$ directly4 ,exp]im5t %[s t ! weights are always 9 accordance ) ! equation 9 ! prec$+ p>agraph4 ,illu/ration3 ,fig4 #cd ,ext5t ( dissociation4 ,! "q w naturally arise1 ,:5 an acid1 base1 or salt dissolves 9 wat]1 d all ! molecules dissociate into ions1 or only a "p ( !m8 ,! exp]im5ts by :i* ?is "q c be answ]$ _c be describ$ "h4 ,x has be5 f\nd1 h[ev]1 t only a fraction ( ! molecules dissociate4 ,! p]c5tage :i* w dissociate 9 a giv5 case dep5ds ^u sev]al conditions1 ! *ief ( :i* are3 7#a7 ,! conc5tration ( ! solution4 ,9 conc5trat$ solutions only a v small p]c5tage ( dissociation occurs4 ,z ! solution is dilut$ ! p]c5tage increases1 & 9 v dilute solutions x may be v l>ge1 ?\gh x is nev] complete 9 any ord9>y solution4 7#b7 ,! nature ( ! dissolv$ comp\nd4 ,at equal conc5trations sub/ances diff] mu* among !mselves 9 ! p]c5tage ( dissociation4 ,! great majority ( salts are ab\t equally dissociat$4 ,acids & bases1 on ! contr>y1 %[ great diff]5ces4 ,"s are freely dissociat$1 :ile o!rs are dissociat$ to b a slight ext5t4 ,/r5g? ( acids & bases4 ,s9ce acid & basic prop]ties are due to hydrog5 & hydroxyl ions respectively1 ! acid or base :i* w produce ! greate/ p]c5tage ( ^! ions at a giv5 conc5tration mu/ be reg>d$ z ! /ronge/ repres5tative ( its class4 ,! acids & bases describ$ 9 ! =ego+ p>agraphs are all q /rong4 ,9 #aj solutions !y are dissociat$ to ab\t #ej1 & ?is is also approximately ! ext5t to :i* mo/ salts are dissociat$ at ?is same conc5tration4 ,p>tial neutralization4 #a4 ,basic salts4 ,! *emical action betwe5 an acid & a base is n always z complete z has be5 repres5t$ 9 ! =ego+ p>agraphs4 ,= example1 if ! base magnesium hydroxide 7,mg7,,oh7#b7 & hydro*loric acid 7,h,cl7 are br\ght toge!r 9 ! ratio ( an equal numb] ( molecules ( ea*1 !re w be only half en\gh hydrog5 ions = ! hydroxyl ions pres5t4 ,mg1 7,,oh7#b ,h1 ,cl ,mg1 ,,oh1 ,cl ,h#b,o4 ,magnesium1 hydroxyl1 & *lor9e ions are left at ! close ( ! reaction1 & "u ! prop] conditions unite to =m molecules ( ! comp\nd ,mg7,,oh7,cl4 ,?is comp\nd1 :5 dissolv$1 c =m hydroxyl ions & !re=e possesses basic prop]ties2 x c also =m ! ions ( a salt 7,mg & ,cl71 & has prop]ties *>act]i/ic ( salts4 ,sub/ances ( ?is k9d are call$ basic salts4 ,,def9ition3 ,a basic salt is a sub/ance :i* c give ! ions bo? ( a base & ( a salt :5 dissolv$ 9 wat]4 #b4 ,acid salts4 ,9 a simil> way1 :5 sulphuric acid & sodium hydroxide are br\ght toge!r 9 ! ratio ( equal numb]s ( ! molecules ( ea*1 x is possible to h a reaction express$ by ! equation ,na1 ,,oh ,h#b1 ,,s#d ,na1 ,h1 ,,s#d ,h#b,o4 ,! ions rema9+ aft] all ! hydroxyl ions h be5 us$ up are ^? ( an acid 7,h7 & ^? ( a salt 7,na & ,,s#d74 ,^! unite to =m ! sub/ance ,na,h,s,o#d1 & z ! solution becomes saturat$ ) ?is sub/ance ?r\gh evaporation1 x sep>ates 9 ! =m ( cry/als4 ,9 solution ?is sub/ance c give hydrog5 ions1 & !re=e possesses acid prop]ties2 x c also give ! ions *>act]i/ic ( a salt4 ,x is !re=e call$ an acid salt4 ,,def9ition3 ,an acid salt is "o :i* c give ! ions ( an acid & ( a salt :5 9 solution4 #c4 ,normal salts4 ,salts :i* are ! products ( complete neutralization1 su* z ,na#b,,s#d1 & :i* 9 solution c give nei!r hydrog5 nor hydroxyl ions1 b only ! ions ( a salt1 are call$ normal salts to di/+ui% !m f acid & basic salts4 ,me?ods ( express+ reactions betwe5 comp\nds 9 solution4 ,*emical equations repres5t+ reactions betwe5 sub/ances 9 solution may repres5t ! details ( ! reaction1 or !y may simply indicate ! f9al products =m$4 ,9 ! latt] case ! =mation ( ions is n indicat$4 ,?us1 if we wi% to call att5tion to ! details ( ! reaction betwe5 sodium hydroxide & hydro*loric acid 9 solution1 ! equation is writt5 z foll[s3 ,na1 ,,oh- ,h1 ,cl- ,na1 ,cl- ,h#b,o4 ,on ! o!r h&1 if we wi% simply to repres5t ! f9al products =m$1 ! foll[+ is us$4 ,na,o,h ,h,cl ,na,cl ,h#b,o4 ,bo? ( ^! me?ods w !re=e be us$3 ,radicals4 ,x has be5 emphasiz$ t ! hydroxyl gr\p 7,,oh7 always =ms ! anion ( a base1 :ile ! gr\p ,,no#c =ms ! anion ( nitric acid & sodium nitrate2 ! gr\p ,,s#d1 ! anion ( sulphuric acid & calcium sulphate4 ,a gr\p ( elem5ts :i* 9 ?is way con/itutes a "p ( a molecule1 act+ z a unit 9 a *emical *ange1 or =m+ ions 9 solution1 is call$ a radical4 ,"s ( ^! radicals h be5 giv5 special names1 ! names signify+ ! elem5ts pres5t 9 ! radical4 ,?us we h ! hydroxyl radical 7,,oh7 & ! nitrate radical 7,,no#c74 ,,def9ition3 ,a radical is a gr\p ( elem5ts =m+ "p ( a molecule1 & act+ z a unit 9 *emical reactions4 ,names ( acids1 bases1 & salts4 ,s9ce acids1 bases1 & salts are s intimately relat$ to ea* o!r1 x is v advantage\s to give names to ! ?ree classes 9 accordance ) "s fix$ sy/em4 ,! sy/em univ]sally adopt$ is z foll[s3 ,nam+ ( bases4 ,all bases are call$ hydroxides4 ,!y are di/+ui%$ f ea* o!r by prefix+ ! "n ( ! elem5t :i* is 9 comb9ation ) ! hydroxyl gr\p4 ,examples3 sodium hydroxide 7,na,o,h72 calcium hydroxide 7,ca7,,oh7#b72 copp] hydroxide 7,cu7,,oh7#b74 ,nam+ ( acids4 ,! me?od ( nam+ acids dep5ds ^u :e!r ! acid consi/s ( two elem5ts or ?ree4 #a4 ,b9>y acids4 ,acids conta9+ only "o elem5t 9 addition to hydrog5 are call$ b9>y acids4 ,!y are giv5 names consi/+ ( ! prefix hydro-1 ! "n ( ! second elem5t pres5t1 & ! t]m9ation -ic4 ,examples3 hydro*loric acid 7,h,cl72 hydrosulphuric acid 7,h#b,s74 #b4 ,t]n>y acids4 ,9 addition to ! two elem5ts pres5t 9 b9>y acids1 ! great majority ( acids also conta9 oxyg54 ,!y !re=e consi/ ( ?ree elem5ts & are call$ t]n>y acids4 ,x usually happ5s t ! same ?ree elem5ts c unite 9 diff]5t proportions to make sev]al diff]5t acids4 ,! mo/ famili> "o ( ^! is giv5 a "n end+ 9 ! suffix -ic1 :ile ! "o ) less oxyg5 is giv5 a simil> "n1 b end+ 9 ! suffix -ous4 ,examples3 nitric acid 7,,hno#c72 nitr\s acid 7,,hno#b74 ,9 cases :]e m ?an two acids are kn[n1 use is made ( prefixes 9 addition to ! two suffixes -ic & -ous4 ,?us ! prefix p]- signifies an acid /ill ri*] 9 oxyg52 ! prefix hypo- signifies "o ) less oxyg54 ,nam+ ( salts4 ,a salt d]iv$ f a b9>y acid is giv5 a "n consi/+ ( ! names ( ! two elem5ts compos+ x1 ) ! t]m9ation -ide4 ,example3 sodium *loride 7,na,cl74 ,all o!r b9>y comp\nds are nam$ 9 ! same way4 ,a salt ( a t]n>y acid is nam$ 9 accordance ) ! acid f :i* x is d]iv$4 ,a t]n>y acid ) ! t]m9ation -ic gives a salt ) ! "n end+ 9 -ate1 :ile an acid ) t]m9ation -ous gives a salt ) ! "n end+ 9 -ite4 ,! foll[+ table w make ! application ( ^! pr9ciples cle>3 ,,acids ,,symbol ,,salts ,,symbol ,hydro*loric ,h,cl ,sodium *loride ,na,cl ,hypo*lor\s ,h,cl,o ,sodium hypo*lorite ,na,cl,o ,*lor\s ,h,cl,o#b ,sodium *lorite ,na,cl,o#b ,*loric ,h,cl,o#c ,sodium *lorate ,na,cl,o#c ,p]*loric ,h,cl,o#d ,sodium p]*lorate ,na,cl,o#d ,,ex]cises #a4 #be cc4 ( a solution conta9+ #dj g4 ( sodium hydroxide p] lit] 0 f\nd to neutralize #be cc4 ( a solution ( hydro*loric acid4 ,:at 0 ! /r5g? ( ! acid solution8 #b4 ,aft] neutraliz+ a solution ( sodium hydroxide ) nitric acid1 !re rema9$ aft] evaporation #ajj g4 ( sodium nitrate4 ,h[ mu* ( ea* sub/ance _h be5 us$8 #c4 ,a solution conta9s #ah g4 ( hydro*loric acid p] #ajj cc4 ,x requir$ #be cc4 ( ?is solution to neutralize #cj cc4 ( a solution ( sodium hydroxide4 ,:at 0 ! /r5g? ( ! sodium hydroxide solution 9 p>ts p] hundr$8 #d4 ,:5 p]fectly dry sulphuric acid is treat$ ) p]fectly dry sodium hydroxide1 no *emical *ange takes place4 ,expla94 #e4 ,:5 cold1 conc5trat$ sulphuric acid is add$ to z9c1 no *ange takes place4 ,recall ! action ( dilute sulphuric acid on ! same metal4 ,h[ d y acc\nt = ! diff]5ce8 #f4 ,a solution ( hydro*loric acid 9 b5z5e does n conduct ! electric curr5t4 ,:5 ?is solution is treat$ ) z9c1 w hydrog5 be evolv$8 ,expla94 #g4 7a7 ,write equation = prep>ation ( hydrog5 f z9c & dilute sulphuric acid4 7b7 ,rewrite ! same equation f ! /&po9t ( ! !ory ( electrolytic dissociation1 7c7 ,subtract ! common ,,s#d ion f bo? memb]s ( ! equation1 7d7 ,f ! result+ equation1 expla9 9 :at ! prep>ation ( hydrog5 consi/s :5 exam9$ f ! /&po9t ( ?is !ory4 #h4 ,9 ! same mann] z 9 ! prec$+ ex]cise1 expla9 9 :at ! action ( sodium on wat] to give hydrog5 consi/s4 ,,*apt] ,,xi ,,val5ce ,def9ition ( val5ce4 ,a /udy ( ! =mulas ( v>i\s b9>y comp\nds %[s t ! elem5ts diff] betwe5 !mselves 9 ! numb] ( atoms ( o!r elem5ts :i* !y are able to hold 9 comb9ation4 ,?is is illu/rat$ 9 ! =mulas ,h,cl1 ,h#b,o1 ,h#c,n1 ,h#d;,c4 7hydro*loric acid7 7wat]7 7ammonia7 7m>% gas7 ,x w be notic$ t :ile "o atom ( *lor9e comb9es ) "o atom ( hydrog51 an atom ( oxyg5 comb9es ) two1 an atom ( nitrog5 ) ?ree1 "o ( c>bon ) f\r4 ,! numb] :i* expresses ?is comb9+ ratio betwe5 atoms is a def9ite prop]ty ( ea* elem5t & is call$ its val5ce4 ,,def9ition3 ,! val5ce ( an elem5t is t prop]ty :i* det]m9es ! numb] ( ! atoms ( ano!r elem5t :i* its atom c hold 9 comb9ation4 ,val5ce a num]ical prop]ty4 ,val5ce is !re=e m]ely a num]ical relation & does n convey any in=mation 9 reg>d to ! int5sity ( ! aff9ity betwe5 atoms4 ,judg+ by ! heat lib]at$ 9 _! union1 oxyg5 has a f> /rong] aff9ity = hydrog5 ?an does nitrog51 b an atom ( oxyg5 c comb9e ) two atoms only ( hydrog51 :ile an atom ( nitrog5 c comb9e ) ?ree4 ,measure ( val5ce4 ,9 express+ ! val5ce ( an elem5t we mu/ select "s /&>d = comp>ison1 j z 9 ! measurem5t ( any o!r num]ical quantity4 ,x has be5 f\nd t an atom ( hydrog5 is nev] able to hold 9 comb9ation m ?an "o atom ( any o!r elem5t4 ,hydrog5 is !re=e tak5 z ! /&>d1 & o!r elem5ts are comp>$ ) x 9 det]m9+ _! val5ce4 ,a numb] ( o!r elem5ts are l hydrog5 9 be+ able to comb9e ) at mo/ "o atom ( o!r elem5ts1 & su* elem5ts are call$ unival5t4 ,among ^! are *lor9e1 iod9e1 & sodium4 ,elem5ts su* z oxyg51 calcium1 & z9c1 :i* c comb9e ) two atoms ( hydrog5 or o!r unival5t elem5ts1 are said to be dival5t4 ,simil>ly1 we h trival5t1 tetraval5t1 p5taval5t elem5ts4 ,none h a val5ce ( m ?an #h4 ,indirect measure ( val5ce4 ,_m elem5ts1 especially among ! metals1 d n readily =m comp\nds ) hydrog51 & _! val5ce is n easy to det]m9e by direct comp>ison ) ! /&>d elem5t4 ,^! elem5ts1 h[ev]1 comb9e ) o!r unival5t elem5ts1 su* z *lor9e1 & _! val5ce c be det]m9$ f ! comp\nds s =m$4 ,v>iable val5ce4 ,_m elem5ts are able to ex]t diff]5t val5ces "u diff]+ circum/ances4 ,?us we h ! comp\nds ,cu#b,o & ,cu,o1 ,,co & ,,co#b1 ,fe,cl#b & ,fe,cl#c4 ,x is n always possible to assign a fix$ val5ce to an elem5t4 ,nev]!less ea* elem5t t5ds to ex]t "s normal val5ce1 & ! comp\nds 9 :i* x has a val5ce diff]5t f ?is are apt to be un/able & easily *ang$ into comp\nds 9 :i* ! val5ce ( ! elem5t is normal4 ,! val5ces ( ! v>i\s elem5ts w become famili> z ! elem5ts are /udi$ 9 detail4 ,val5ce & comb9+ ratios4 ,:5 elem5ts comb9e to =m comp\nds1 ! ratio 9 :i* !y comb9e w be det]m9$ by _! val5ces4 ,9 ^? comp\nds :i* consi/ ( two elem5ts directly comb9$1 ! union is betwe5 su* numb]s ( ! two atoms z h equal val5ces4 ,elem5ts ( ! same val5ce w !re=e comb9e atom = atom4 ,designat+ ! val5ce ( ! atoms by ,roman num]als plac$ above _! symbols1 we h ! =mulas ,,ii ,,ii ,,ii ,,iii ,,iii ,,iv ,,iv ,h,cl1 ,zn,o1 ,,bn1 ,c,si4 ,a dival5t elem5t1 on ! o!r h&1 w comb9e ) two atoms ( a unival5t elem5t4 ,?us we h ,,ii ,,ii ,,ii ,,ii ,zn,cl#b & ,h#b,o 7! num]als above ea* symbol repres5t+ ! sum ( ! val5ces ( ! atoms ( ! elem5t pres5t74 ,a trival5t atom w comb9e ) ?ree atoms ( a unival5t elem5t1 z 9 ! comp\nd ,,iii ,,iii ,h#c,n4 ,if a trival5t elem5t comb9es ) a dival5t elem5t1 ! union w be betwe5 two atoms ( ! trival5t elem5t & ?ree ( ! dival5t elem5t1 s9ce ^! numb]s are ! smalle/ :i* h equal val5ces4 ,?us ! oxide ( ! trival5t metal alum9ium has ! =mula ,al#b,o#c4 ,f9ally "o atom ( a tetraval5t elem5t su* z c>bon w comb9e ) f\r atoms ( a unival5t elem5t1 z 9 ! comp\nd ,,*#d1 or ) two atoms ( a dival5t elem5t1 z 9 ! comp\nd ,,co#b4 ,we h no k z to :y elem5ts diff] 9 _! comb9+ p[]1 & !re is no way to det]m9e _! val5ces save by exp]im5t4 ,val5ce & ! /ructure ( comp\nds4 ,comp\nds w be met f "t to "t :i* are app>5t exceptions to ! g5]al /atem5ts j made 9 reg>d to val5ce4 ,?us1 f ! =mula = hydrog5 dioxide 7,h#b,o#b71 x might be suppos$ t ! oxyg5 is unival5t2 yet x is c]ta9ly dival5t 9 wat] 7,h#b,o74 ,t x may also be dival5t 9 ,h#b,o#b may be made cle> z foll[s3 ,! unit val5ce ( ea* elem5t may be repres5t$ graphically by a l9e atta*$ to its symbol4 ,unival5t hydrog5 & dival5t oxyg5 w !n h ! symbols ,h- & -,o-4 ,:5 atoms comb9e1 ea* unit val5ce ( "o atom comb9es ) a unit val5ce ( ano!r atom4 ,?us ! composition ( wat] may be express$ by ! =mula ,h-,o-,h1 :i* is meant to %[ t ea* ( ! unit val5ces ( oxyg5 is satisfi$ ) ! unit val5ce ( a s+le hydrog5 atom4 ,! *emical conduct ( hydrog5 dioxide leads to ! conclusion t ! two oxyg5 atoms ( its molecule are 9 direct comb9ation ) ea* o!r1 & 9 addition ea* is 9 comb9ation ) a hydrog5 atom4 ,?is may be express$ by ! =mula ,h-,o-,o-,h4 ,! oxyg5 9 ! comp\nd is !re=e dival5t1 j z x is 9 wat]4 ,x w ?us be se5 t ! /ructure ( a comp\nd mu/ be kn[n be=e ! val5ces ( ! atoms mak+ up ! comp\nd c be def9itely decid$ ^u4 ,su* =mulas z ,h-,o-,h & ,h-,o-,o-,h are kn[n z /ructural =mulas1 because !y are int5d$ to %[ :at is kn[n 9 reg>d to ! arrangem5t ( ! atoms 9 ! molecules4 ,val5ce & ! replac+ p[] ( atoms4 ,j z elem5ts hav+ ! same val5ce comb9e ) ea* o!r atom = atom1 s if !y replace ea* o!r 9 a *emical reaction !y w d s 9 ! same ratio4 ,?is is se5 9 ! foll[+ equations1 9 :i* a unival5t hydrog5 atom is replac$ by a unival5t sodium atom3 ,na,o,h ,h,cl ,na,cl ,h#b,o4 #b,na,o,h ,h#b,,s#d ,na#b,,s#d #b;,h#b,o4 ,na ,h#b,o ,na,o,h ,h4 ,simil>ly1 "o atom ( dival5t calcium w replace two atoms ( unival5t hydrog5 or "o ( dival5t z9c3 ,ca7,,oh7#b #b ,h,cl ,ca,cl#b #b;,h#b,o4 ,ca,cl#b ,zn,s,o#d ,ca,s,o#d ,zn,cl#b4 ,9 l mann]1 "o atom ( a trival5t elem5t w replace ?ree ( a unival5t elem5t1 or two atoms w replace ?ree atoms ( a dival5t elem5t4 ,val5ce & its applications to =mulas ( salts4 ,:ile ! true nature ( val5ce is n und]/ood & _m que/ions connect$ ) ! subject rema9 unansw]$1 yet _m ( ! ma9 facts are ( mu* help to ! /ud5t4 ,?us ! =mula ( a salt1 diff]s f t ( ! acid f :i* x is d]iv$ 9 t ! hydrog5 ( ! acid has be5 replac$ by a metal4 ,if1 !n1 x is kn[n t a giv5 metal =ms a normal salt ) a c]ta9 acid1 ! =mula ( ! salt c at once be det]m9$ if ! val5ce ( ! metal is kn[n4 ,s9ce sodium is unival5t1 ! sodium salts ( ! acids ,h,cl & ,h#b,,s#d w be respectively ,na,cl & ,na#b,,s#d4 ,"o atom ( dival5t z9c w replace #b hydrog5 atoms1 s t ! correspond+ z9c salts w be ,zn,cl#b & ,zn,s,o#d4 ,! =mula = alum9ium sulphate is some:at m difficult to det]m9e4 ,alum9ium is trival5t1 & ! simple/ ratio 9 :i* ! alum9ium atom c replace ! hydrog5 9 sulphuric acid is #b atoms ( alum9ium 7#f val5ces7 to #c molecules ( sulphuric acid 7#f hydrog5 atoms74 ,! =mula ( ! sulphate w !n be ,al#b7,,s#d7c4 ,val5ce & its application to equation writ+4 ,x w be readily se5 t a k ( val5ce is also ( v great assi/ance 9 writ+ ! equations = reactions ( d\ble decomposition4 ,?us1 9 ! g5]al reaction betwe5 an acid & a base1 ! ess5tial action is betwe5 ! unival5t hydrog5 ion & ! unival5t hydroxyl ion4 ,! base & ! acid mu/ always be tak5 9 su* proportions z to secure an equal numb] ( ea* ( ^! ions4 ,?us1 9 ! reaction betwe5 f]ric hydroxide 7,fe7,,oh7#c7 & sulphuric acid 7,h#b,,s#d71 x w be necess>y to take #b molecules ( ! =m] & #c ( ! latt] 9 ord] to h an equal numb] ( ! two ions1 namely1 #f4 ,! equation w !n be #b;,fe7,,oh7#c #c;,h#b,,s#d ,fe#b7,,s#d7c #f;,h#b,o4 ,"u c]ta9 conditions ! salts ,al#b7,,s#d7c & ,ca,cl#b und]go d\ble decomposition1 ! two metals1 alum9ium & calcium1 ex*ang+ places4 ,! simple/ ratio ( ex*ange 9 ?is case is #b atoms ( alum9ium 7#f val5ces7 & #c atoms ( calcium 7#f val5ces74 ,! reaction w !re=e take place betwe5 #a molecule ( ,al#b7,,s#d7c & #c ( ,ca,cl#b1 & ! equation is z foll[s3 ,al#b7,,s#d7c #c ,ca,cl#b #c;,ca,s,o#d #b;,al,cl#c4 ,,ex]cises #a4 ,sodium1 calcium1 & alum9ium h val5ces ( #a1 #b1 & #c respectively2 write ! =mulas ( _! *lorides1 sulphates1 & phosphates 7phosphoric acid ,h#c,,po#d71 on ! supposition t !y =m salts hav+ ! normal composition4 #b4 ,iron =ms "o s]ies ( salts 9 :i* x has a val5ce ( #b1 & ano!r s]ies 9 :i* x has a val5ce ( #c2 write ! =mulas = ! two *lorides ( iron1 also = ! two sulphates1 on ! supposition t ^! h ! normal composition4 #c4 ,write ! equation repres5t+ ! neutralization ( ea* ( ! foll[+ bases by ea* ( ! acids ^: =mulas are giv53 ,na,o,h ,h,cl ,ba7,,oh7#b ,h#b,,s#d ,al7,,oh7#c ,h#c,,po#d #d4 ,silv] acts z a unival5t elem5t & calcium z a dival5t elem5t 9 ! =mation ( _! respective nitrates & *lorides4 7a7 ,write ! =mula = silv] nitrate2 = calcium *loride4 7b7 ,:5 solutions ( ^! two salts are mix$1 ! two metals1 silv] & calcium1 ex*ange places2 write ! equation = ! reaction4 #e4 ,antimony acts z a trival5t elem5t 9 ! =mation ( a *loride4 7a7 ,:at is ! =mula = antimony *loride8 7b7 ,:5 hydrosulphuric acid 7,h#b,s7 is pass$ into a solution ( ?is *loride ! hydrog5 & antimony ex*ange places2 write ! equation = ! reaction4 #f4 ,lead has a val5ce ( #b & iron ( #c 9 ! comp\nds kn[n respectively z lead nitrate & f]ric sulphate4 7a7 ,write ! =mulas = ^! two comp\nds4 7b7 ,:5 _! solutions are mix$ ! two metals ex*ange places2 write ! equation = ! reaction4 ,,*apt] ,,xii ,,comp\nds ,,( ,,nitrog5 ,occurr5ce4 ,z has be5 /at$ 9 a =m] *apt]1 nitrog5 con/itutes a l>ge fraction ( ! atmosph]e4 ,! comp\nds ( nitrog51 h[ev]1 _c readily be obta9$ f ?is s\rce1 s9ce at any ord9>y temp]ature nitrog5 is able to comb9e directly ) v few ( ! elem5ts4 ,9 c]ta9 =ms ( comb9ation nitrog5 occurs 9 ! soil f :i* x is tak5 up by plants & built into complex sub/ances compos$ *iefly ( c>bon1 hydrog51 oxyg51 & nitrog54 ,animals fe$+ on ^! plants assimilate ! nitrog5\s matt]1 s t ?is elem5t is an ess5tial con/itu5t ( bo? plants & animals4 ,decomposition ( organic matt] by bact]ia4 ,:5 liv+ matt] dies & und]goes decay complicat$ *emical reactions take place1 "o result ( :i* is t ! nitrog5 ( ! organic matt] is set free ei!r z ! elem5t nitrog51 or 9 ! =m ( simple comp\nds1 su* z ammonia 7,,nh#c7 or oxides ( nitrog54 ,exp]im5t has %[n t all su* processes ( decay are due to ! action ( diff]5t k9ds ( bact]ia1 ea* p>ticul> k9d effect+ a diff]5t *ange4 ,decomposition ( organic matt] by heat4 ,:5 organic matt] is /rongly heat$ decomposition into simpl] sub/ances takes place 9 mu* ! same way z 9 ! case ( bact]ial decomposition4 ,coal is a complex sub/ance ( vegetable orig91 consi/+ l>gely ( c>bon1 b also conta9+ hydrog51 oxyg51 & nitrog54 ,:5 ?is is heat$ 9 a clos$ vessel s t air is exclud$1 ab\t "o sev5? ( ! nitrog5 is conv]t$ into ammonia1 & ?is is ! *ief s\rce f :i* ammonia & its comp\nds are obta9$4 ,,comp\nds ,,( ,,nitrog5 ,,) ,,hydrog5 ,ammonia 7,,nh#c74 ,sev]al comp\nds consi/+ exclusively ( nitrog5 & hydrog5 are kn[n1 b only "o1 ammonia1 ne$ be consid]$ "h4 ,prep>ation ( ammonia4 ,ammonia is prep>$ 9 ! laboratory by a diff]5t me?od f ! "o :i* is us$ comm]cially4 #a4 ,laboratory me?od4 ,9 ! laboratory ammonia is prep>$ f ammonium *loride1 a comp\nd hav+ ! =mula ,,nh#d;,cl1 & obta9$ 9 ! manufacture ( coal gas4 ,z w be %[n lat] 9 ! *apt]1 ! gr\p ,,nh#d 9 ?is comp\nd acts z a unival5t radical & is kn[n z ammonium4 ,:5 ammonium *loride is w>m$ ) sodium hydroxide1 ! ammonium & sodium *ange places1 ! reaction be+ express$ 9 ! foll[+ equation4 ,,nh#d;,cl ,na,o,h ,na,cl ,,nh#d,,oh4 ,! ammonium hydroxide 7,,nh#d,,oh7 s =m$ is un/able & breaks d[n into wat] & ammonia4 ,,nh#d,,oh ,,nh#c ,h#b,o4 ,calcium hydroxide 7,ca7,,oh7#b7 is frequ5tly us$ 9 place ( ! m exp5sive sodium hydroxide1 ! equations be+ #b,,nh#d;,cl ,ca7,,oh7#b ,ca,cl#b #b,,nh#d,,oh1 #b,,nh#d,,oh #b;,h#b,o #b,,nh#c4 ,9 ! prep>ation1 ! ammonium *loride & calcium hydroxide are mix$ toge!r & plac$ 9 a flask arrang$ z %[n 9 ,fig4 #ce4 ,! mixture is g5tly w>m$1 :5 ammonia is evolv$ z a gas & is collect$ by displacem5t ( air4 ,illu/ration3 ,fig4 #ce #b4 ,comm]cial me?od4 ,ne>ly all ! ammonia ( comm]ce comes f ! gasworks4 ,ord9>y illum9at+ gas is made by di/ill+ coal1 z w be expla9$ lat]1 & among ! products ( ?is di/illation a solution ( ammonia 9 wat] is obta9$4 ,?is solution1 kn[n z gas liquor1 conta9s n only ammonia b o!r soluble sub/ances4 ,mo/ ( ^! comb9e *emically ) lime1 :ile ammonia does n2 if !n lime is add$ to ! gas liquor & ! liquor is heat$1 ! ammonia is driv5 out f ! mixture4 ,x may be dissolv$ aga9 9 pure1 cold wat]1 =m+ aqua ammonia1 or ! ammonia wat] ( comm]ce4 ,prep>ation f hydrog5 & nitrog54 ,:5 electric sp>ks are pass$ = "s "t ?r\gh a mixture ( hydrog5 & nitrog51 a small p]c5tage ( ! two elem5ts 9 ! mixture is *ang$ into ammonia4 ,! action soon ceases1 h[ev]1 = ! reason t ammonia is decompos$ by ! electric dis*>ge4 ,! reaction express$ 9 ! equation ,n #c;,h ,,nh#c c !re=e g 9 ei!r direction dep5d+ ^u ! relative quantities ( ! sub/ances pres5t4 ,?is recalls ! simil> *ange f oxyg5 into ozone1 :i* soon ceases because ! ozone is 9 turn decompos$ into oxyg54 ,physical prop]ties4 ,"u ord9>y conditions ammonia is a gas ^: d5sity is #j4ei4 ,x is !re=e little m ?an half z heavy z air4 ,x is easily cond5s$ into a colorless liquid1 & c n[ be pur*as$ 9 liquid =m 9 /eel cyl9d]s4 ,! gas is colorless & has a /rong1 suffocat+ odor4 ,x is extremely soluble 9 wat]1 #a l4 ( wat] at #j & #gfj mm4 pressure dissolv+ #aadh l4 ( ! gas4 ,9 dissolv+ ?is l>ge volume ( gas ! wat] exp&s consid]ably1 s t ! d5sity ( ! solution is less ?an t ( wat]1 ! /ronge/ solutions hav+ a d5sity ( #j4hh4 ,*emical prop]ties4 ,ammonia w n support combu/ion1 nor w x burn "u ord9>y conditions4 ,9 an atmosph]e ( oxyg5 x burns ) a feeble1 yell[i% flame4 ,:5 q dry x is n a v active sub/ance1 b :5 moi/ x comb9es ) a great _m sub/ances1 p>ticul>ly ) acids4 ,uses4 ,x has be5 /at$ t ammonia c be cond5s$ to a liquid by ! application ( pressure4 ,if ! pressure is remov$ f ! liquid s obta9$1 x rapidly passes aga9 into ! gase\s /ate & 9 s do+ absorbs a l>ge am\nt ( heat4 ,advantage is tak5 ( ?is fact 9 ! prep>ation ( artificial ice4 ,l>ge quantities ( ammonia are also us$ 9 ! prep>ation ( ammonium comp\nds4 ,! manufacture ( artificial ice4 ,fig4 #cf illu/rates ! me?od ( prep>+ artificial ice4 ,! ammonia gas is liquefi$ 9 ! pipes ,x by means ( ! pump ,y4 ,! heat g5]at$ is absorb$ by wat] fl[+ ov] ! pipes4 ,! pipes lead into a l>ge br9e tank1 a cross section ( :i* is %[n 9 ! figure4 ,into ! br9e 7conc5trat$ solution ( common salt7 conta9$ 9 ?is tank are dipp$ ! vessels ,a1 ,b1 ,c1 fill$ ) pure wat]4 ,! pressure is remov$ f ! liquid ammonia z x passes into ! pipes imm]s$ 9 ! br9e1 & ! heat absorb$ by ! rapid evaporation ( ! liquid l[]s ! temp]ature ( ! br9e bel[ z]o4 ,! wat] 9 ,a1 ,b1 ,c is !reby froz5 into cakes ( ice4 ,! gase\s ammonia result+ f ! evaporation ( ! liquid ammonia is aga9 cond5s$1 s t ! process is cont9u\s4 ,illu/ration ,fig4 #cf ,ammonium hydroxide 7,,nh#d,,oh74 ,! solution ( ammonia 9 wat] is f\nd to h /rong basic prop]ties & !re=e conta9s hydroxyl ions4 ,x turns r$ litmus blue2 x has a soapy feel2 x neutralizes acids1 =m+ salts ) !m4 ,x seems probable1 !re=e1 t :5 ammonia dissolves 9 wat] x comb9es *emically ) x accord+ to ! equation ,,nh#c ,h#b,o ,,nh#d,,oh1 & t x is ! sub/ance ,,nh#d,,oh1 call$ ammonium hydroxide1 :i* has ! basic prop]ties1 dissociat+ into ! ions ,,nh#d & ,,oh4 ,ammonium hydroxide has nev] be5 obta9$ 9 a pure /ate4 ,at e attempt to isolate x ! sub/ance breaks up into wat] & ammonia1-- ,,nh#d,,oh ,,nh#c ,h#b,o4 ,! ammonium radical4 ,! radical ,,nh#d plays ! "p ( a metal 9 _m *emical reactions & is call$ ammonium4 ,! end+ -ium is giv5 to ! "n to indicate ! metallic prop]ties ( ! sub/ance1 s9ce ! names ( ! metals 9 g5]al h t end+4 ,! salts =m$ by ! action ( ! base ammonium hydroxide on acids are call$ ammonium salts4 ,?us1 ) hydro*loric acid1 ammonium *loride is =m$ 9 accordance ) ! equation ,,nh#d,,oh ,h,cl ,,nh#d;,cl ,h#b,o4 ,simil>ly1 ) nitric acid1 ammonium nitrate 7,,nh#d,,no#c7 is =m$1 & ) sulphuric acid1 ammonium sulphate 77,,nh#d7b,s#jd74 ,x w be notic$ t 9 ! neutralization ( ammonium hydroxide by acids ! gr\p ,,nh#d replaces "o hydrog5 atom ( ! acid1 j z sodium does4 ,! gr\p !re=e acts z a unival5t metal4 ,comb9ation ( nitrog5 ) hydrog5 by volume4 ,"u suitable conditions ammonia c be decompos$ into nitrog5 & hydrog5 by pass+ electric sp>ks ?r\gh ! gas4 ,accurate measurem5t has %[n t :5 ammonia is decompos$1 two volumes ( ! gas yield "o volume ( nitrog5 & ?ree volumes ( hydrog54 ,consequ5tly1 if ! two elem5ts 7 to comb9e directly1 "o volume ( nitrog5 w\ld comb9e ) ?ree volumes ( hydrog5 to =m two volumes ( ammonia4 ,"h1 z 9 ! =mation ( /eam f hydrog5 & oxyg51 small :ole numb]s s]ve to indicate ! relation betwe5 ! volumes ( comb9+ gases & t ( ! gase\s product4 ,,comp\nds ,,( ,,nitrog5 ,,) ,,oxyg5 ,,& ,,hydrog5 ,9 addition to ammonium hydroxide1 nitrog5 =ms sev]al comp\nds ) hydrog5 & oxyg51 ( :i* nitric acid 7,,hno#c7 & nitr\s acid 7,,hno#b7 are ! mo/ famili>4 ,nitric acid 7,,hno#c74 ,nitric acid is n f\nd to any ext5t 9 nature1 b "s ( its salts1 especially sodium nitrate 7,na,n,o#c7 & potassium nitrate 7,,kno#c7 are f\nd 9 l>ge quantities4 ,f ^! salts nitric acid c be obta9$4 ,illu/ration ,fig4 #cg ,prep>ation ( nitric acid4 ,:5 sodium nitrate is treat$ ) conc5trat$ cold sulphuric acid1 no *emical action seems to take place4 ,if1 h[ev]1 ! mixture is heat$ 9 a retort1 nitric acid is giv5 (f z a vapor & may be easily cond5s$ to a liquid by pass+ ! vapor into a tube surr\nd$ by cold wat]1 z %[n 9 ,fig4 #cg4 ,an exam9ation ( ! liquid left 9 ! retort %[s t x conta9s sodium acid sulphate 7,na,h,s,o#d71 s t ! reaction may be repres5t$ by ! equation ,na,n,o#c ,h#b,,s#d ,na,h,s,o#d ,,hno#c4 ,if a small] quantity ( sulphuric acid is tak5 & ! mixture is heat$ to a high temp]ature1 normal sodium sulphate is =m$3 #b,na,n,o#c ,h#b,,s#d ,na#b,,s#d #b;,,hno#c4 ,9 ?is case1 h[ev]1 ! high] temp]ature requir$ decomposes a "p ( ! nitric acid4 ,! comm]cial prep>ation ( nitric acid4 ,fig4 #ch illu/rates a =m ( app>atus us$ 9 ! prep>ation ( nitric acid on a l>ge scale4 ,sodium nitrate & sulphuric acid are heat$ 9 ! iron retort ,a4 ,! result+ acid vapors pass 9 ! direction indicat$ by ! arr[s1 & are cond5s$ 9 ! glass tubes ,b1 :i* are cov]$ ) clo? kept cool by /reams ( wat]4 ,^! tubes are incl9$ s t ! liquid result+ f ! cond5sation ( ! vapors runs back into ,c & is drawn (f into l>ge vessels 7,d74 ,illu/ration ,fig4 #ch ,physical prop]ties ( nitric acid4 ,pure nitric acid is a colorless liquid1 :i* boils at ab\t #hf & has a d5sity ( #a4ef4 ,! conc5trat$ acid ( comm]ce conta9s ab\t #fh ( ! acid1 ! rema9d] be+ wat]4 ,su* a mixture has a d5sity ( #a4d4 ,! conc5trat$ acid fumes some:at 9 moi/ air1 & has a %>p *ok+ odor4 ,*emical prop]ties4 ,! mo/ important *emical prop]ties ( nitric acid are ! foll[+4 #a4 ,acid prop]ties4 ,z ! "n indicates1 ?is sub/ance is an acid1 & has all ! prop]ties ( t class ( sub/ances4 ,x *anges blue litmus r$ & has a s\r ta/e 9 dilute solutions4 ,x =ms hydrog5 ions 9 solution & neutralizes bases =m+ salts4 ,x also acts ^u ! oxides ( mo/ metals1 =m+ a salt & wat]4 ,x is "o ( ! /ronge/ acids4 #b4 ,decomposition on heat+4 ,:5 boil$1 or expos$ = "s "t to sunlight1 x suff]s a p>tial decomposition accord+ to ! equation #b;,,hno#c ,h#b,o #b,,no#b ,o4 ,! sub/ance ,,no#b1 call$ nitrog5 p]oxide1 is a br[ni% gas1 :i* is readily soluble 9 wat] & 9 nitric acid4 ,x !re=e dissolves 9 ! undecompos$ acid1 & imp>ts a yell[i% or r$di% color to x4 ,conc5trat$ nitric acid highly *>g$ ) ?is sub/ance is call$ fum+ nitric acid4 #c4 ,oxidiz+ action4 ,accord+ to its =mula1 nitric acid conta9s a l>ge p]c5tage ( oxyg51 & ! reaction j m5tion$ %[s t ! comp\nd is n a v /able "o1 easily und]go+ decomposition4 ,^! prop]ties %\ld make x a good oxidiz+ ag5t1 & we f9d t ?is is ! case4 ,"u ord9>y circum/ances1 :5 act+ z an oxidiz+ ag5t1 x is decompos$ accord+ to ! equation #b;,,hno#c ,h#b,o #b,,no #c,o4 ,! oxyg5 is tak5 up by ! sub/ance oxidiz$1 & n set free1 z is indicat$ 9 ! equation4 ,?us1 if c>bon is oxidiz$ by nitric acid1 ! oxyg5 comb9es ) c>bon1 =m+ c>bon dioxide 7,,co#b73 ,c #b,o ,,co#b4 #d4 ,action on metals4 ,we h se5 t :5 an acid acts ^u a metal hydrog5 is set free4 ,accord+ly1 :5 nitric acid acts ^u a metal1 su* z copp]1 we %\ld expect ! reaction to take place :i* is express$ 9 ! equation ,cu #b;,,hno#c ,cu7,,no#c7b #b;,h4 ,?is reaction does take place1 b ! hydrog5 set free is imm$iately oxidiz$ to wat] by ano!r portion ( ! nitric acid accord+ to ! equation ,,hno#c #c;,h #b;,h#b,o ,,no4 ,z ^! two equations are writt51 two atoms ( hydrog5 are giv5 (f 9 ! fir/ equation1 :ile ?ree are us$ up 9 ! second4 ,9 ord] t ! hydrog5 may be equal 9 ! two equations1 we mu/ multiply ! fir/ by #c & ! second by #b4 ,we %all !n h #c;,cu #f;,,hno#c #c;,cu7,,no#c7b #f;,h1 #b;,,hno#c #f;,h #d;,h#b,o #b,,no4 ,! two equations may n[ be comb9$ into "o by add+ ! quantities on ea* side ( ! equality sign1 cancel+ ! hydrog5 :i* is giv5 (f 9 ! "o reaction & us$ up 9 ! o!r4 ,we %all !n h ! equation #c;,cu #h;,,hno#c #c;,cu7,,no#c7b #b,,no #d;,h#b,o4 ,a numb] ( o!r reactions may take place :5 nitric acid acts ^u metals1 result+ 9 ! =mation ( o!r oxides ( nitrog51 free nitrog51 or ev5 ammonia4 ,! reaction j giv5 is1 h[ev]1 ! usual "o4 ,importance ( /eps 9 a reaction4 ,?is complete equation has ! advantage ( mak+ x possible to calculate v easily ! proportions 9 :i* ! v>i\s sub/ances ent] into ! reaction or are =m$ 9 x4 ,x is unsatisfactory 9 t x does n give full in=mation ab\t ! way 9 :i* ! reaction takes place4 ,= example1 x does n sugge/ t hydrog5 is at fir/ =m$1 & subsequ5tly trans=m$ into wat]4 ,x is always mu* m important to rememb] ! /eps 9 a *emical reaction ?an to rememb] ! equation express+ ! complete action2 = if ^! /eps 9 ! reaction are und]/ood1 ! complete equation is easily obta9$ 9 ! mann] j describ$4 ,salts ( nitric acid1--nitrates4 ,! salts ( nitric acid are call$ nitrates4 ,_m ( ^! salts w be describ$ 9 ! /udy ( ! metals4 ,!y are all soluble 9 wat]1 & :5 heat$ to a high temp]ature und]go decomposition4 ,9 a few cases a nitrate on be+ heat$ evolves oxyg51 =m+ a nitrite3 ,na,n,o#c ,na,n,o#b ,o4 ,9 o!r cases ! decomposition goes fur!r1 & ! metal is left z oxide3 ,cu7,,no#c7b ,cu,o #b,,no#b ,o4 ,nitr\s acid 7,,hno#b74 ,x is an easy matt] to obta9 sodium nitrite 7,na,n,o#b71 z ! reaction giv5 on ! previ\s page indicates4 ,in/ead ( m]ely heat+ ! nitrate1 x is bett] to heat x toge!r ) a mild r$uc+ ag5t1 su* z lead1 :5 ! reaction takes place :i* is express$ by ! equation ,na,n,o#c ,pb ,pb,o ,na,n,o#b4 ,:5 sodium nitrite is treat$ ) an acid1 su* z sulphuric acid1 x is decompos$ & nitr\s acid is set free3 ,na,n,o#b ,h#b,,s#d ,na,h,s,o#d ,,hno#b4 ,! acid is v un/able1 h[ev]1 & decomposes readily into wat] & nitrog5 trioxide 7,n#b,o#c73 #b;,,hno#b ,h#b,o ,n#b,o#c4 ,dilute solutions ( ! acid1 h[ev]1 c be obta9$4 ,,comp\nds ,,( ,,nitrog5 ,,) ,,oxyg5 ,nitrog5 comb9es ) oxyg5 to =m five diff]5t oxides4 ,! =mulas & names ( ^! are z foll[s3 ,n#b,o nitr\s oxide4 ,,no nitric oxide4 ,,no#b nitrog5 p]oxide4 ,n#b,o#c nitrog5 trioxide1 or nitr\s anhydride4 ,n#b,o#e nitrog5 p5toxide1 or nitric anhydride4 ,^! w n[ be briefly discuss$4 ,nitr\s oxide 7laugh+ gas7 7,n#b,o74 ,ammonium nitrate1 l all nitrates1 und]goes decomposition :5 heat$2 & ow+ to ! fact t x conta9s no metal1 b does conta9 bo? oxyg5 & hydrog51 ! reaction is a peculi> "o4 ,x is repres5t$ by ! equation ,,nh#d,,no#c #b;,h#b,o ,n#b,o4 ,! oxide ( nitrog5 s =m$ is call$ nitr\s oxide or laugh+ gas4 ,x is a colorless gas hav+ a slight odor4 ,x is some:at soluble 9 wat]1 & 9 solution has a slightly sweeti% ta/e4 ,x is easily conv]t$ into a liquid & c be pur*as$ 9 ?is =m4 ,:5 inhal$ x produces a k9d ( hy/]ia 7h5ce ! "n laugh+ gas71 & ev5 unconsci\sness & ins5sibility to pa9 if tak5 9 l>ge am\nts4 ,x has long be5 us$ z an an/hetic = m9or surgical op]ations1 su* z ^? ( d5ti/ry1 b ow+ to its unpleasant aft] effects x is n s mu* 9 use n[ z =m]ly4 ,*emically1 nitr\s oxide is rem>kable = ! fact t x is a v en]getic oxidiz+ ag5t4 ,sub/ances su* z c>bon1 sulphur1 iron1 & phosphorus burn 9 x almo/ z brilliantly z 9 oxyg51 =m+ oxides & sett+ free nitrog54 ,evid5tly ! oxyg5 9 nitr\s oxide _c be held 9 v firm comb9ation by ! nitrog54 ,illu/ration ,fig4 #ci ,nitric oxide 7,,no74 ,we h se5 t :5 nitric acid acts ^u metals1 su* z copp]1 ! reaction repres5t$ by ! foll[+ equation takes place3 #c;,cu #h;,,hno#c #c;,cu7,,no#c7c #b,,no #d;,h#b,o4 ,nitric oxide is mo/ conv5i5tly prep>$ 9 ?is way4 ,! metal is plac$ 9 ! flask ,a 7,fig4 #ci7 & ! acid add$ sl[ly ?r\gh ! funnel tube ,b4 ,! gas escapes ?r\gh ,c & is collect$ ov] wat]4 ,pure nitric oxide is a colorless gas1 slightly heavi] ?an air1 & is practically insoluble 9 wat]4 ,x is a difficult gas to liquefy4 ,unlike nitr\s oxide1 nitric oxide does n "p ) its oxyg5 easily1 & burn+ sub/ances introduc$ into ?is gas are usually ext+ui%$4 ,a few sub/ances l phosphorus1 :i* h a v /rong aff9ity = oxyg5 & :i* are burn+ en]getically 9 ! air1 w cont9ue to burn 9 an atmosph]e ( nitric oxide4 ,9 ?is case ! nitric oxide loses all ( its oxyg5 & ! nitrog5 is set free z gas4 ,action ( nitric oxide ) oxyg54 ,:5 nitric oxide comes into contact ) oxyg5 or ) ! air1 x at once comb9es ) ! oxyg5 ev5 at ord9>y temp]atures1 =m+ a r$di%-yell[ gas ( ! =mula ,,no#b1 :i* is call$ nitrog5 p]oxide4 ,?is action is n en]getic en\gh to produce a flame1 ?\gh consid]able heat is set free4 ,nitrog5 p]oxide 7,,no#b74 ,?is gas1 z we h j se51 is =m$ by all[+ nitric oxide to come into contact ) oxyg54 ,x c also be made by heat+ c]ta9 nitrates1 su* z lead nitrate3 ,pb7,,no#c7b ,pb,o #b,,no#b ,o4 ,x is a r$di%-yell[ gas ( unpleasant odor1 :i* is q poison\s :5 inhal$4 ,x is heavi] ?an air & is easily cond5s$ to a liquid4 ,x dissolves 9 wat]1 b ?is solution is n a m]e physical solution2 ! nitrog5 p]oxide is decompos$1 =m+ a mixture ( nitric & nitr\s acids3 #b,,no#b ,h#b,o ,,hno#b ,,hno#c4 ,nitrog5 p]oxide w n comb9e ) m oxyg52 x w1 h[ev]1 give up a "p ( its oxyg5 to burn+ sub/ances1 act+ z an oxidiz+ ag5t3 ,,no#b ,,no ,o4 ,acid anhydrides4 ,! oxides ,n#b,o#c 7nitrog5 trioxide7 & ,n#b,o#e 7nitrog5 p5toxide7 are r>ely prep>$ & ne$ n be sep>ately describ$4 ,!y be> a v int]e/+ relation to ! acids ( nitrog54 ,:5 dissolv$ 9 wat] !y comb9e ) ! wat]1 =m+ acids3 ,n#b,o#c ,h#b,o #b;,,hno#b1 ,n#b,o#e ,h#b,o #b;,,hno#c4 ,on ! o!r h&1 nitr\s acid v easily decomposes1 yield+ wat] & nitrog5 trioxide1 & by suitable means nitric acid likewise may be decompos$ into wat] & nitrog5 p5toxide3 #b;,,hno#b ,h#b,o ,n#b,o#c1 #b;,,hno#c ,h#b,o ,n#b,o#e4 ,9 view ( ! close relation betwe5 ^! oxides & ! correspond+ acids1 !y are call$ anhydrides ( ! acids1 ,n#b,o#c be+ nitr\s anhydride & ,n#b,o#e nitric anhydride4 ,,def9ition3 ,any oxide :i* w comb9e ) wat] to =m an acid1 or :i* toge!r ) wat] is =m$ by ! decomposition ( an acid1 is call$ an anhydride ( t acid4 ,,ex]cises #a4 ,p]fectly dry ammonia does n affect litmus pap]4 ,expla94 #b4 ,c ammonia be dri$ by pass+ ! gas ?r\gh conc5trat$ sulphuric acid8 ,expla94 #c4 ,ammonium hydroxide is a weak base1 i4e4 x is n highly dissociat$4 ,:5 x is neutraliz$ by /rong acids ! heat ( reaction is less ?an :5 /rong bases are s neutraliz$4 ,sugge/ "s possible cause = ?is4 #d4 ,:y is br9e us$ 9 ! manufacture ( artificial ice8 #e4 ,discuss ! en]gy *anges :i* take place 9 ! manufacture ( artificial ice4 #f4 ,:at weight ( ammonium *loride is necess>y to furni% en\gh ammonia to saturate #a l4 ( wat] at #j & #gfj mm48 #g4 ,:at weight ( sodium nitrate is necess>y to prep>e #ajj cc4 ( comm]cial nitric acid8 ,:at weight ( potassium nitrate is necess>y to furni% ! same weight ( acid8 #h4 #ajj l4 ( nitrog5 p]oxide 7 dissolv$ 9 wat] & neutraliz$ ) sodium hydroxide4 ,:at sub/ances 7 =m$ & h[ mu* ( ea*87#a l4 nitrog5 p]oxide weighs #b4je grams47 #i4 ,h[ _m lit]s ( nitr\s oxide1 measur$ "u /&>d conditions1 c be prep>$ f #aj g4 ( ammonium nitrate8 #aj4 ,:at weight ( copp] is necess>y to prep>e #ej l4 ( nitric oxide "u /&>d conditions8 #aa4 7a7 ,calculate ! p]c5tage composition ( ! oxides ( nitrog54 7b7 ,:at important law does ?is s]ies ( sub/ances illu/rate8 #ab4 ,write ! equations repres5t+ ! reactions betwe5 ammonium hydroxide1 & sulphuric acid & nitric acid respectively1 9 accordance ) ! !ory ( electrolytic dissociation4 #ac4 ,9 ! same way1 write ! equations repres5t+ ! reactions betwe5 nitric acid & ea* ( ! foll[+ bases3 ,na,o,h1 ,,koh1 ,,nh#d,,oh1 ,ca7,,oh7#b4 ,,*apt] ,,xiii ,,rev]sible ,,reactions ,,& ,,*emical ,,equilibrium ,rev]sible reactions4 ,! reactions s f> consid]$ h be5 repres5t$ z cont9u+1 :5 once />t$1 until "o or ! o!r sub/ance tak+ "p 9 ! reaction has be5 us$ up4 ,9 "s reactions ?is is n ! case4 ,= example1 we h se5 t :5 /eam is pass$ ov] hot iron ! reaction is repres5t$ by ! equation #c;,fe #d;,h#b,o ,fe#c,o#d #h;,h4 ,on ! o!r h&1 :5 hydrog5 is pass$ ov] hot iron oxide ! rev]se reaction takes place3 ,fe#c,o#d #h;,h #c;,fe #d;,h#b,o4 ,! reaction c !re=e g 9 ei!r direction1 dep5d+ ^u ! conditions ( ! exp]im5t4 ,su* a reaction is call$ a rev]sible reaction4 ,x is repres5t$ by an equation ) d\ble arr[s 9 place ( ! equality sign1 ?us3 #c;,fe #d;,h#b,o -- ,fe#c,o#d #h;,h4 ,9 a simil> way1 ! equation ,n #c;,h -- ,,nh#c expresses ! fact t "u "s conditions nitrog5 may unite ) hydrog5 to =m ammonia1 :ile "u o!r conditions ammonia decomposes into nitrog5 & hydrog54 ,! conv]sion ( oxyg5 into ozone is also rev]sible & may be repres5t$ ?us3 oxyg5 -- ozone4 ,*emical equilibrium4 ,rev]sible reactions d n usually g on to completion 9 "o direction unless ! conditions "u :i* ! reaction takes place are v c>efully *os54 ,?us1 if iron & /eam are conf9$ 9 a heat$ tube1 ! /eam acts ^u ! iron1 produc+ iron oxide & hydrog54 ,b ^! sub/ances 9 turn act ^u ea* o!r to =m iron & /eam once m4 ,:5 ^! two opposite reactions g on at su* rates t ! weight ( ! iron *ang$ into iron oxide is j balanc$ by ! weight ( ! iron oxide *ang$ into iron1 !re w be no fur!r *ange 9 ! relative weights ( ! f\r sub/ances pres5t 9 ! tube4 ,! reaction is !n said to h rea*$ an equilibrium4 ,factors :i* det]m9e ! po9t ( equilibrium4 ,!re are two factors :i* h a great deal ( influ5ce 9 det]m9+ ! po9t at :i* a giv5 reaction w rea* equilibrium4 #a4 ,influ5ce ( ! *emical nature ( ! sub/ances4 ,if two rev]sible reactions ( ! same g5]al k9d are select$1 x has be5 f\nd t ! po9t ( equilibrium is diff]5t 9 ! two cases4 ,= example1 9 ! reactions repres5t$ by ! equations #c;,fe #d;,h#b,o -- ,fe#c,o#d #h;,h1 ,zn ,h#b,o -- ,zn,o #b;,h1 ! equilibrium w be rea*$ :5 v diff]5t quantities ( ! iron & z9c h be5 *ang$ into oxides4 ,! individual *emical prop]ties ( ! iron & z9c h !re=e m>k$ influ5ce ^u ! po9t at :i* equilibrium w be rea*$4 #b4 ,influ5ce ( relative mass4 ,if ! tube 9 :i* ! reaction #c;,fe #d;,h#b,o -- ,fe#c,o#d #h;,h has come to an equilibrium is op5$ & m /eam is admitt$1 an additional quantity ( ! iron w be *ang$ into iron oxide4 ,if m hydrog5 is admitt$1 "s ( ! oxide w be r$uc$ to metal4 ,! po9t ( equilibrium is !re=e dep5d5t ^u ! relative masses ( ! sub/ances tak+ "p 9 ! reaction4 ,:5 "o ( ! sub/ances is a solid1 h[ev]1 its mass has little influ5ce1 s9ce x is only ! ext5t ( its surface :i* c affect ! reaction4 ,conditions "u :i* rev]sible reactions are complete4 ,if1 :5 ! equilibrium betwe5 iron & /eam has be5 rea*$1 ! tube is op5$ & a curr5t ( /eam is pass$ 91 ! hydrog5 is swept away z fa/ z x is =m$4 ,! oppos+ reaction ( hydrog5 ^u iron oxide mu/ !re=e cease1 & ! action ( /eam on ! iron w g on until all ( ! iron has be5 trans=m$ into iron oxide4 ,on ! o!r h&1 if a curr5t ( hydrog5 is admitt$ into ! tube1 ! /eam w be swept away by ! hydrog51 & all ( ! iron oxide w be r$uc$ to iron4 ,a rev]sible reaction c !re=e be complet$ 9 ei!r direction :5 "o ( ! products ( ! reaction is remov$ z fa/ z x is =m$4 ,equilibrium 9 solution4 ,:5 reactions take place 9 solution 9 wat] ! same g5]al pr9ciples hold good4 ,! matt] is n s simple1 h[ev]1 z 9 ! case j describ$1 ow+ to ! fact t _m ( ! reactions 9 solution are due to ! pres5ce ( ions4 ,! sub/ances mo/ commonly employ$ 9 solution are acids1 bases1 or salts1 & all ( ^! und]go dissociation4 ,any equilibrium :i* may be rea*$ 9 solutions ( ^! sub/ances mu/ take place betwe5 ! v>i\s ions =m$1 on ! "o h&1 & ! undissociat$ molecules1 on ! o!r4 ,?us1 :5 nitric acid is dissolv$ 9 wat]1 equilibrium is rea*$ 9 accordance ) ! equation ,h ,,no#c- -- ,,hno#c4 ,conditions "u :i* rev]sible reactions 9 solution are complete4 ,! equilibrium betwe5 sub/ances 9 solution may be di/urb$ & ! reaction caus$ to g on 9 "o direction to completion 9 ei!r ( ?ree ways4 #a4 ,a gas may be =m$ :i* escapes f ! solution4 ,:5 sodium nitrate & sulphuric acid are br\ght toge!r 9 solution all f\r ions1 ,na1 ,,no#c-1 ,h1 ,,s#d--1 are =m$4 ,^! ions are free to re>range !mselves 9 v>i\s comb9ations4 ,= example1 ! ,h & ! ,,no#c- ions w rea* ! equilibrium ,h ,,no#c- -- ,,hno#c4 ,if ! exp]im5t is p]=m$ ) v little wat] pres5t1 z is ! case 9 ! prep>ation ( nitric acid1 ! equilibrium w be rea*$ :5 mo/ ( ! ,h & ! ,,no#c- ions h comb9$ to =m undissociat$ ,,hno#c4 ,f9ally1 if ! mixture is n[ heat$ above ! boil+ po9t ( nitric acid1 ! acid di/ills away z fa/ z x is =m$4 ,m & m ,h & ,,no#c- ions w !n comb9e1 & ! process w cont9ue until "o or ! o!r ( !m has all be5 remov$ f ! solution4 ,! sub/ance rema9+ is sodium acid sulphate 7,na,h,s,o#d71 & ! reaction c !re=e be express$ by ! equation ,na,n,o#c ,h#b,,s#d ,na,h,s,o#d ,,hno#c4 #b4 ,an insoluble solid may be =m$4 ,:5 hydro*loric acid 7,h,cl7 & silv] nitrate 7,ag,n,o#c7 are br\ght toge!r 9 solution ! foll[+ ions w be pres5t3 ,h1 ,cl-1 ,ag1 ,,no#c-4 ,! ions ,ag & ,cl- w !n set up ! equilibrium ,ag ,cl- -- ,ag,cl4 ,b silv] *loride 7,ag,cl7 is almo/ completely insoluble 9 wat]1 & z soon z a v little ( x has =m$ ! solution becomes sup]saturat$1 & ! excess ( ! salt precipitates4 ,m silv] & *lor9e ions !n unite1 & ?is cont9ues until practically all ( ! silv] or ! *lor9e ions h be5 remov$ f ! solution4 ,we !n say t ! foll[+ reaction is complete3 ,ag,n,o#c ,h,cl ,ag,cl ,,hno#c4 #c4 ,two diff]5t ions may =m undissociat$ molecules4 ,9 ! neutralization ( sodium hydroxide by hydro*loric acid ! ions ,h & ,,oh- come to ! equilibrium ,h ,,oh- -- ,h#b,o4 ,b s9ce wat] is almo/ entirely undissociat$1 equilibrium c only be rea*$ :5 !re are v few hydroxyl or hydrog5 ions pres5t4 ,consequ5tly ! two ions keep unit+ until "o or ! o!r ( !m is practically remov$ f ! solution4 ,:5 ?is occurs ! neutralization express$ 9 ! foll[+ equation is complete3 ,na,o,h ,h,cl ,h#b,o ,na,cl4 ,prep>ation ( acids4 ,! pr9ciple ( rev]sible reactions f9ds practical application 9 ! prep>ation ( mo/ ( ! common acids4 ,an acid is usually prep>$ by treat+ ! mo/ common ( its salts ) "s o!r acid ( high boil+ po9t4 ,! mixture is !n heat$ until ! l[] boil+ acid desir$ di/ills out4 ,ow+ to its high boil+ po9t 7#cch71 sulphuric acid is usually employ$ = ?is purpose1 mo/ o!r acids boil+ bel[ t temp]ature4 ,,ex]cises #a4 ,:at w\ld take place :5 solutions ( silv] nitrate & sodium *loride are br\ght toge!r8 ,:at o!r *lorides w\ld act 9 ! same way8 #b4 ,is ! reaction express$ by ! equation ,,nh#c ,h#b,o ,,nh#d,,oh rev]sible8 ,if s1 /ate ! conditions "u :i* x w g 9 ea* direction4 #c4 ,is ! reaction express$ by ! equation #b;,h ,o ,h#b,o rev]sible8 ,if s1 /ate ! conditions "u :i* x w g 9 ea* direction4 #d4 ,sugge/ a me?od = ! prep>ation ( hydro*loric acid4 ,,*apt] ,,xiv ,,sulphur ,,& ,,its ,,comp\nds ,occurr5ce4 ,! elem5t sulphur has be5 kn[n f ! e>lie/ times1 s9ce x is widely di/ribut$ 9 nature & occurs 9 l>ge quantities 9 ! uncomb9$ =m1 especially 9 ! neighborhood ( volcanoes4 ,sicily has long be5 fam\s = its sulphur m9es1 & small] deposits are f\nd 9 ,italy1 ,icel&1 ,mexico1 & especially 9 ,l\isiana1 :]e x is m9$ ext5sively4 ,9 comb9ation1 sulphur occurs abundantly 9 ! =m ( sulphides & sulphates4 ,9 small] am\nts x is f\nd 9 a great v>iety ( m9]als1 & x is a con/itu5t ( _m animal & vegetable sub/ances4 ,extraction ( sulphur4 ,sulphur is prep>$ f ! native sub/ance1 ! sep>ation ( crude sulphur f ! rock & e>?y mat]ials ) :i* x is mix$ be+ a v simple process4 ,! ore f ! m9es is m]ely heat$ until ! sulphur melts & dra9s away f ! e>?y impurities4 ,! crude sulphur obta9$ 9 ?is way is di/ill$ 9 a retort-%ap$ vessel made ( iron1 ! exit tube ( :i* op5s into a cool+ *amb] ( brickwork4 ,:5 ! sulphur vapor fir/ ent]s ! cool+ *amb] x cond5ses z a f9e cry/all9e p[d] call$ fl[]s ( sulphur4 ,z ! cond5s+ *amb] becomes w>m1 ! sulphur collects z a liquid 9 x1 & is drawn (f into cyl9drical molds1 ! product be+ call$ roll sulphur or brim/one4 ,physical prop]ties4 ,roll sulphur is a pale yell[1 cry/all9e solid1 )\t m>k$ ta/e & ) b a fa9t odor4 ,x is insoluble 9 wat]1 b is freely soluble 9 a few liquids1 notably 9 c>bon disulphide4 ,roll sulphur melts at #aad4h4 ,j above ! melt+ po9t x =ms a r ?91 /raw-color$ liquid4 ,z ! temp]ature is rais$1 ?is liquid turns d>k] 9 color & becomes ?ick]1 until at ab\t #bce x is almo/ black & is s ?ick t ! vessel conta9+ x c be inv]t$ )\t dang] ( ! liquid runn+ out4 ,at high] temp]atures x becomes ?9 once m1 & boils at #ddh1 =m+ a yell[i% vapor4 ,on cool+ ! same *anges take place 9 rev]se ord]4 ,v>ieties ( sulphur4 ,sulphur is kn[n 9 two g5]al =ms1 cry/all9e & amorph\s4 ,ea* ( ^! =ms exi/s 9 def9ite modifications4 ,cry/all9e sulphur4 ,sulphur occurs 9 two cry/all9e =ms1 namely1 rhombic sulphur & monocl9ic sulphur4 #a4 ,rhombic sulphur4 ,:5 sulphur cry/allizes f its solution 9 c>bon disulphide x sep>ates 9 cry/als :i* h ! same color & melt+ po9t z roll sulphur1 & are rhombic 9 %ape4 ,roll sulphur is made up ( m9ute rhombic cry/als4 #b4 ,monocl9ic sulphur4 ,:5 melt$ sulphur is all[$ to cool until a "p ( ! liquid has solidifi$1 & ! rema9+ liquid is !n p\r$ (f1 x is f\nd t ! solid sulphur rema9+ 9 ! vessel has assum$ ! =m ( f9e ne$le-%ap$ cry/als4 ,^! diff] mu* 9 appe>ance f ! rhombic cry/als obta9$ by cry/alliz+ sulphur f its solution 9 c>bon disulphide4 ,! ne$le-%ap$ =m is call$ monocl9ic sulphur4 ,! two v>ieties diff] also 9 d5sity & 9 melt+ po9t1 ! monocl9ic sulphur melt+ at #abj4 ,monocl9ic & rhombic sulphur rema9 un*ang$ 9 contact ) ea* o!r at #if4 ,above ?is temp]ature ! rhombic *anges into monocl9ic2 at l[] temp]atures ! monocl9ic *anges into rhombic4 ,! temp]ature #if is !re=e call$ ! transition po9t ( sulphur4 ,heat is set free :5 monocl9ic sulphur *anges into rhombic4 ,amorph\s sulphur4 ,two v>ieties ( amorph\s sulphur c be readily obta9$4 ,^! are :ite sulphur & pla/ic sulphur4 #a4 ,:ite sulphur4 ,fl[]s ( sulphur1 ! prep>ation ( :i* has be5 describ$1 consi/s ( a mixture ( rhombic cry/als & amorph\s p>ticles4 ,:5 treat$ ) c>bon disulphide1 ! cry/als dissolve1 leav+ ! amorph\s p>ticles z a :ite residue4 #b4 ,pla/ic sulphur4 ,:5 boil+ sulphur is p\r$ into cold wat] x assumes a gummy1 d\ghlike =m1 :i* is q ela/ic4 ,?is c be se5 9 a v /rik+ mann] by di/ill+ sulphur f a small1 %ort-neck$ retort1 su* z is repres5t$ 9 ,fig4 #dj1 & all[+ ! liquid to run directly into wat]4 ,9 a few days x becomes q brittle & passes ov] into ord9>y rhombic sulphur4 ,illu/ration ,fig4 #dj ,*emical prop]ties ( sulphur4 ,:5 sulphur is heat$ to its k9dl+ temp]ature 9 oxyg5 or 9 ! air x burns ) a pale blue flame1 =m+ sulphur dioxide 7,,s#b74 ,small quantities ( sulphur trioxide 7,,s#c7 may also be =m$ 9 ! combu/ion ( sulphur4 ,mo/ metals :5 heat$ ) sulphur comb9e directly ) x1 =m+ metallic sulphides4 ,9 "s cases ! action is s en]getic t ! mass becomes inc&esc5t1 z has be5 se5 9 ! case ( iron unit+ ) sulphur4 ,?is prop]ty recalls ! action ( oxyg5 ^u metals1 & 9 g5]al ! metals :i* comb9e readily ) oxyg5 are apt to comb9e q readily ) sulphur4 ,uses ( sulphur4 ,l>ge quantities ( sulphur are us$ z a g]micide 9 v9ey>ds1 also 9 ! manufacture ( gunp[d]1 mat*es1 vulcaniz$ rubb]1 & sulphuric acid4 ,,comp\nds ,,( ,,sulphur ,,) ,,hydrog5 ,hydrosulphuric acid 7,h#b,s74 ,?is sub/ance is a gas hav+ ! composition express$ by ! =mula ,h#b,s & is commonly call$ hydrog5 sulphide4 ,x is f\nd 9 ! vapors issu+ f volcanoes1 & 9 solution 9 ! s-call$ sulphur wat]s ( _m spr+s4 ,x is =m$ :5 organic matt] conta9+ sulphur und]goes decay1 j z ammonia is =m$ "u simil> circum/ances f nitrog5\s matt]4 ,prep>ation4 ,hydrosulphuric acid is prep>$ 9 ! laboratory by treat+ a sulphide ) an acid4 ,iron sulphide 7,fe,s7 is usually employ$3 ,fe,s #b;,h,cl ,fe,cl#b ,h#b,s4 ,a conv5i5t app>atus is %[n 9 ,fig4 #da4 ,a few lumps ( iron sulphide are plac$ 9 ! bottle ,a1 & dilute acid is add$ 9 small quantities at a "t ?r\gh ! funnel tube ,b1 ! gas escap+ ?r\gh ! tube ,c4 ,illu/ration3 ,fig4 #da ,explanation ( ! reaction4 ,iron sulphide is a salt ( hydrosulphuric acid1 & ?is reaction is !re=e simil> to ! "o :i* takes place :5 sulphuric acid acts ^u a nitrate4 ,9 bo? cases a salt & an acid are br\ght toge!r1 & !re is a t5d5cy = ! reaction to g on until a /ate ( equilibrium is rea*$4 ,?is equilibrium is con/antly di/urb$ by ! escape ( ! gase\s acid set free1 s t ! reaction goes on until all ( ! orig9al salt has be5 decompos$4 ,! two reactions diff] 9 t ! fir/ "o is complete at ord9>y temp]atures1 :ile 9 ! case ( sulphuric acid act+ ^u sodium nitrate1 ! react+ sub/ances mu/ be heat$ s z to secure a temp]ature at :i* nitric acid is a gas4 ,physical prop]ties4 ,hydrosulphuric acid is a colorless gas1 hav+ a weak1 disagreeable ta/e & an exce$+ly (f5sive odor4 ,x is r sp>+ly soluble 9 wat] at ord9>y temp]atures1 ab\t ?ree volumes dissolv+ 9 "o ( wat]4 ,9 boil+ wat] x is n soluble at all4 ,9 pure =m x acts z a viol5t poison1 & ev5 :5 dilut$ l>gely ) air produces heada*e1 dizz9ess1 & nausea4 ,x is a little heavi] ?an air1 hav+ a d5sity ( #a4ah4 ,*emical prop]ties4 ,! mo/ important *emical prop]ties ( hydrosulphuric acid are ! foll[+3 #a4 ,acid prop]ties4 ,hydrosulphuric acid is a weak acid4 ,9 solution 9 wat] x turns blue litmus r$ & neutralizes bases1 =m+ salts call$ sulphides4 #b4 ,action on oxyg54 ,! elem5ts compos+ hydrosulphuric acid h ea* a /rong aff9ity = oxyg51 & are n held toge!r v firmly4 ,consequ5tly ! gas burns readily 9 oxyg5 or ! air1 accord+ to ! equation ,h#b,s #c,o ,h#b,o ,,s#b4 ,:5 !re is n en\gh oxyg5 = bo? ! sulphur & ! hydrog51 ! latt] elem5t comb9es ) ! oxyg5 & ! sulphur is set free3 ,h#b,s ,o ,h#b,o ,s4 #c4 ,r$uc+ action4 ,ow+ to ! ease ) :i* hydrosulphuric acid decomposes & ! /rong aff9ity ( bo? sulphur & hydrog5 = oxyg51 ! sub/ance is a /rong r$uc+ ag5t1 tak+ oxyg5 away f _m sub/ances :i* conta9 x4 #d4 ,action on metals4 ,hydrosulphuric acid acts t[>ds metals 9 a way v simil> to wat]4 ,?us1 :5 x is pass$ ov] heat$ iron 9 a tube1 ! reaction is repres5t$ by ! equation #c;,fe #d;,h#b,s ,fe#c,s#d #h;,h4 ,wat] 9 ! =m ( /eam1 "u simil> circum/ances1 acts accord+ to ! equation #c;,fe #d;,h#b,o ,fe#c,o#d #h;,h4 ,salts ( hydrosulphuric acid1--sulphides4 ,! salts ( hydrosulphuric acid1 call$ sulphides1 =m an important class ( salts4 ,_m ( !m are f\nd abundantly 9 nature1 & "s ( !m are important ores4 ,!y w be frequ5tly m5tion$ 9 connection ) ! metals4 ,mo/ ( ! sulphides are insoluble 9 wat]1 & "s ( !m are insoluble 9 acids4 ,consequ5tly1 :5 hydrosulphuric acid is pass$ into a solution ( a salt1 x (t5 happ5s t a sulphide is precipitat$4 ,) copp] *loride ! equation is ,cu,cl#b ,h#b,s ,cu,s #b;,h,cl4 ,because ( ! fact t "s metals are precipitat$ 9 ?is way z sulphides :ile o!rs are n1 hydrosulphuric acid is ext5sively us$ 9 ! sep>ation ( ! metals 9 ! laboratory4 ,explanation ( ! reaction4 ,:5 hydrosulphuric acid & copp] *loride are br\ght toge!r 9 solution1 bo? copp] & sulphur ions are pres5t1 & ^! w come to an equilibrium1 z repres5t$ 9 ! equation ,cu ,s- -- ,cu,s4 ,s9ce copp] sulphide is almo/ insoluble 9 wat]1 z soon z a v small quantity has =m$ ! solution becomes sup]saturat$1 & ! excess keeps precipitat+ until ne>ly all ! copp] or sulphur ions h be5 remov$ f ! solution4 ,) "s o!r ions1 su* z iron1 ! sulphide =m$ does n saturate ! solution1 & no precipitate results4 ,,oxides ,,( ,,sulphur ,sulphur =ms two well-kn[n comp\nds ) oxyg53 sulphur dioxide 7,,s#b71 sometimes call$ sulphur\s anhydride2 & sulphur trioxide 7,,s#c71 frequ5tly call$ sulphuric anhydride4 ,sulphur dioxide 7,,s#b74 ,sulphur dioxide occurs 9 nature 9 ! gases issu+ f volcanoes1 & 9 solution 9 ! wat] ( _m spr+s4 ,x is likely to be f\nd :]ev] sulphur comp\nds are und]go+ oxidation4 ,prep>ation4 ,?ree g5]al ways may be m5tion$ = ! prep>ation ( sulphur dioxide3 #a4 ,by ! combu/ion ( sulphur4 ,sulphur dioxide is readily =m$ by ! combu/ion ( sulphur 9 oxyg5 or ! air3 ,s #b,o ,,s#b4 ,x is also =m$ :5 sub/ances conta9+ sulphur are burn$3 ,zn,s #c,o ,zn,o ,,s#b4 #b4 ,by ! r$uction ( sulphuric acid4 ,:5 conc5trat$ sulphuric acid is heat$ ) c]ta9 metals1 su* z copp]1 "p ( ! acid is *ang$ into copp] sulphate1 & "p is r$uc$ to sulphur\s acid4 ,! latt] !n decomposes into sulphur dioxide & wat]1 ! complete equation be+ ,cu #b;,h#b,,s#d ,cu,s,o#d ,,s#b #b;,h#b,o4 #c4 ,by ! action ( an acid on a sulphite4 ,sulphites are salts ( sulphur\s acid 7,h#b,,s#c74 ,:5 a sulphite is treat$ ) an acid1 sulphur\s acid is set free1 & be+ v un/able1 decomposes into wat] & sulphur dioxide4 ,^! reactions are express$ 9 ! equations ,na#b,,s#c #b;,h,cl #b,na,cl ,h#b,,s#c1 ,h#b,,s#c ,h#b,o ,,s#b4 ,explanation ( ! reaction4 ,9 ?is case we h two rev]sible reactions dep5d+ on ea* o!r4 ,9 ! fir/ reaction1 7#a7 ,na#b,,s#c #b;,h,cl -- #b,na,cl ,h#b,,s#c1 we %\ld expect an equilibrium to result1 = none ( ! f\r sub/ances 9 ! equation are insoluble or volatile :5 wat] is pres5t to hold !m 9 solution4 ,b ! quantity ( ! ,h#b,,s#c is con/antly dim9i%+1 ow+ to ! fact t x decomposes1 z repres5t$ 9 ! equation 7#b7 ,h#b,,s#c -- ,h#b,o ,,s#b1 & ! sulphur dioxide1 be+ a gas1 escapes4 ,no equilibrium c !re=e result1 s9ce ! quantity ( ! sulphur\s acid is con/antly be+ dim9i%$ because ( ! escape ( sulphur dioxide4 ,physical prop]ties4 ,sulphur dioxide is a colorless gas1 :i* at ord9>y temp]atures is #b4b times z heavy z air4 ,x has a peculi>1 irritat+ odor4 ,! gas is v soluble 9 wat]1 "o volume ( wat] dissolv+ eighty ( ! gas "u /&>d conditions4 ,x is easily cond5s$ to a colorless liquid1 & c be pur*as$ 9 ?is condition /or$ 9 /rong bottles1 su* z ! "o repres5t$ 9 ,fig4 #db4 ,illu/ration3 ,fig4 #db ,*emical prop]ties4 ,sulphur dioxide has a m>k$ t5d5cy to comb9e ) o!r sub/ances1 & is !re=e an active sub/ance *emically4 ,x comb9es ) oxyg5 gas1 b n v easily4 ,x c1 h[ev]1 take oxyg5 away f "s o!r sub/ances1 & is !re=e a good r$uc+ ag5t4 ,its mo/ m>k$ *emical prop]ty is its ability to comb9e ) wat] to =m sulphur\s acid 7,h#b,,s#c74 ,sulphur\s acid 7,h#b,,s#c74 ,:5 sulphur dioxide dissolves 9 wat] x comb9es *emically ) x to =m sulphur\s acid1 an un/able sub/ance hav+ ! =mula ,h#c,,s#c4 ,x is impossible to prep>e ?is acid 9 pure =m1 z x breaks d[n v easily into wat] & sulphur dioxide4 ,! reaction is !re=e rev]sible1 & is express$ by ! equation ,h#b,o ,,s#b -- ,h#b,,s#c4 ,solutions ( ! acid 9 wat] h a numb] ( int]e/+ prop]ties4 #a4 ,acid prop]ties4 ,! solution has all ! prop]ties typical ( an acid4 ,:5 neutraliz$ by bases1 sulphur\s acid yields a s]ies ( salts call$ sulphites4 #b4 ,r$uc+ prop]ties4 ,solutions ( sulphur\s acid act z good r$uc+ ag5ts4 ,?is is due to ! fact t sulphur\s acid has ! p[] ( tak+ up oxyg5 f ! air1 or f sub/ances ri* 9 oxyg51 & is *ang$ by ?is reaction into sulphuric acid3 ,h#b,,s#c ,o ,h#b,,s#d1 ,h#b,,s#c ,h#b,o#b ,h#b,s#jd ,h#b,o4 #c4 ,blea*+ prop]ties4 ,sulphur\s acid has /rong blea*+ prop]ties1 act+ ^u _m color$ sub/ances 9 su* a way z to de/roy _! color4 ,x is on ?is acc\nt us$ to blea* pap]1 /raw goods1 & ev5 su* foods z cann$ corn4 #d4 ,antiseptic prop]ties4 ,sulphur\s acid has m>k$ antiseptic prop]ties1 & on ?is acc\nt has ! p[] ( arre/+ f]m5tation4 ,x is !re=e us$ z a pres]vative4 ,salts ( sulphur\s acid1--sulphites4 ,! sulphites1 l sulphur\s acid1 h ! p[] ( tak+ up oxyg5 v readily1 & are good r$uc+ ag5ts4 ,on acc\nt ( ?is t5d5cy1 comm]cial sulphites are (t5 contam9at$ ) sulphates4 ,a great deal ( sodium sulphite is us$ 9 ! blea*+ indu/ry1 & z a reag5t = s(t5+ pap] pulp4 ,sulphur trioxide 7,,s#c74 ,:5 sulphur dioxide & oxyg5 are heat$ toge!r at a r high temp]ature1 a small am\nt ( sulphur trioxide 7,,s#c7 is =m$1 b ! reaction is sl[ & incomplete4 ,if1 h[ev]1 ! heat+ takes place 9 ! pres5ce ( v f9e plat9um du/1 ! reaction is rapid & ne>ly complete4 ,illu/ration3 ,fig4 #dc ,exp]im5tal prep>ation ( sulphur trioxide4 ,! exp]im5t c be p]=m$ by ! use ( ! app>atus %[n 9 ,fig4 #dc1 ! f9e plat9um be+ secur$ by moi/5+ asbe/os fib] ) a solution ( plat9um *loride & ignit+ x 9 a flame4 ,! fib]1 cov]$ ) f9e plat9um1 is plac$ 9 a tube ( h>d glass1 :i* is !n heat$ ) a burn] to ab\t #cej1 :ile sulphur dioxide & air are pass$ into ! tube4 ,union takes place at once1 & ! /rongly fum+ sulphur trioxide escapes f ! jet at ! end ( ! tube1 & may be cond5s$ by surr\nd+ ! receiv+ tube ) a freez+ mixture4 ,prop]ties ( sulphur trioxide4 ,sulphur trioxide is a colorless liquid1 :i* solidifies at ab\t #ae & boils at #df4 ,a trace ( moi/ure causes x to solidify into a mass ( silky :ite cry/als1 some:at resembl+ asbe/os fib] 9 appe>ance4 ,9 contact ) ! air x fumes /rongly1 & :5 ?r[n ^u wat] x dissolves ) a hiss+ s\nd & ! lib]ation ( a great deal ( heat4 ,! product ( ?is reaction is sulphuric acid1 s t sulphur trioxide is ! anhydride ( t acid3 ,,s#c ,h#b,o ,h#b,,s#d4 ,catalysis4 ,x has be5 f\nd t _m *emical reactions1 su* z ! union ( sulphur dioxide ) oxyg51 are mu* influ5c$ by ! pres5ce ( sub/ances :i* d n !mselves seem to take a "p 9 ! reaction1 & are left app>5tly un*ang$ aft] x has ceas$4 ,^! reactions g on v sl[ly "u ord9>y circum/ances1 b are greatly ha/5$ by ! pres5ce ( ! =eign sub/ance4 ,sub/ances :i* ha/5 v sl[ reactions 9 ?is way are said to act z catalytic ag5ts or catalyz]s1 & ! action is call$ catalysis4 ,j h[ ! action is br\ght ab\t is n well und]/ood4 ,,def9ition3 ,a catalyz] is a sub/ance :i* *anges ! velocity ( a reaction1 b does n *ange its products4 ,examples ( ,catalysis4 ,we h already _h sev]al in/ances ( su* action4 ,oxyg5 & hydrog5 comb9e ) ea* o!r at ord9>y temp]atures 9 ! pres5ce ( plat9um p[d]1 :ile if no catalytic ag5t is pres5t !y d n comb9e 9 appreciable quantities until a r high temp]ature is rea*$4 ,potassium *lorate1 :5 heat$ ) manganese dioxide1 gives up its oxyg5 at a mu* l[] temp]ature ?an :5 heat$ alone4 ,hydrog5 dioxide decomposes v rapidly :5 p[d]$ manganese dioxide is sift$ into its conc5trat$ solution4 ,on ! o!r h&1 ! catalytic ag5t sometimes ret>ds *emical action4 ,= example1 a solution ( hydrog5 dioxide decomposes m sl[ly :5 x conta9s a little phosphoric acid ?an :5 p]fectly pure4 ,= ?is reason comm]cial hydrog5 dioxide always conta9s phosphoric acid4 ,_m reactions are br\ght ab\t by ! catalytic action ( traces ( wat]4 ,= example1 phosphorus w n burn 9 oxyg5 9 ! abs5ce ( all moi/ure4 ,hydro*loric acid w n unite ) ammonia if ! reag5ts are p]fectly dry4 ,x is probable t _m ( ! *emical trans=mations 9 physiological processes1 su* z dige/ion1 are assi/$ by c]ta9 sub/ances act+ z catalytic ag5ts4 ,! pr9ciple ( catalysis is !re=e v important4 ,sulphuric acid 7oil ( vitriol7 7,h#b,,s#d74 ,sulphuric acid is "o ( ! mo/ important ( all manufactur$ *emicals4 ,n only is x "o ( ! mo/ common reag5ts 9 ! laboratory1 b enorm\s quantities ( x are us$ 9 _m ( ! indu/ries1 especially 9 ! ref9+ ( petroleum1 ! manufacture ( nitroglyc]91 sodium c>bonate1 & f]tiliz]s4 ,manufacture ( sulphuric acid4 #a4 ,contact process4 ,! reactions tak+ place 9 ?is process are repres5t$ by ! foll[+ equations3 ,,s#b ,o ,,s#c1 ,,s#c ,h#b,o ,h#b,,s#d4 ,to br+ ab\t ! fir/ ( ^! reactions rapidly1 a catalyz] is employ$1 & ! process is c>ri$ out 9 ! foll[+ way3 ,l>ge iron tubes are pack$ ) "s por\s mat]ial1 su* z calcium & magnesium sulphates1 :i* conta9s a suitable catalytic sub/ance scatt]$ ?r\gh x4 ,! catalyz]s mo/ us$ are plat9um p[d]1 vanadium oxide1 & iron oxide4 ,purifi$ sulphur dioxide & air are pass$ ?r\gh ! tubes1 :i* are kept at a temp]ature ( ab\t #cej4 ,sulphur trioxide is =m$1 & z x issues f ! tube x is absorb$ 9 wat] or dilute sulphuric acid4 ,! process is cont9u$ until all ! wat] 9 ! absorb+ vessel has be5 *ang$ into sulphuric acid1 s t a v conc5trat$ acid is made 9 ?is way4 ,an excess ( ! trioxide may dissolve 9 ! /rong sulphuric acid1 =m+ :at is kn[n z fum+ sulphuric acid4 #b4 ,*amb] process4 ,! me?od ( manufacture exclusively employ$ until rec5t ye>s1 & /ill 9 v ext5sive use1 is mu* m complicat$4 ,! reactions are q involv$1 b ! conv]sion ( wat]1 sulphur dioxide1 & oxyg5 into sulphuric acid is accompli%$ by ! catalytic action ( oxides ( nitrog54 ,! reactions are br\ght ab\t 9 l>ge lead-l9$ *amb]s1 into :i* oxides ( nitrog51 sulphur dioxide1 /eam1 & air are introduc$ 9 suitable proportions4 ,reactions ( ! *amb] process4 ,9 a v g5]al way1 ! v>i\s reactions :i* take place 9 ! lead *amb]s may be express$ 9 two equations4 ,9 ! fir/ reaction sulphur dioxide1 nitrog5 p]oxide1 /eam1 & oxyg5 unite1 z %[n 9 ! equation 7#a7 #b,,s#b #b,,no#b ,h#b,o ,o #b,,s#b 7,,oh7 7,,no#b74 ,! product =m$ 9 ?is reaction is call$ nitrosulphuric acid or *amb] cry/als4 ,x actually sep>ates on ! walls ( ! *amb]s :5 ! process is n work+ prop]ly4 ,"u normal conditions1 x is decompos$ z fa/ z x is =m$ by ! action ( excess ( /eam1 z %[n 9 ! equation 7#b7 #b,,s#b 7,,oh7 7,,no#b7 ,h#b,o ,o #b;,h#b,,s#d #b,,no#b4 ,! nitrog5 dioxide =m$ 9 ?is reaction c n[ ent] into comb9ation ) a new quantity ( sulphur dioxide1 /eam1 & oxyg51 & ! s]ies ( reactions g on indef9itely4 ,_m o!r reactions occur1 b ^! two illu/rate ! pr9ciple ( ! process4 ,! relation betwe5 sulphuric acid & nitrosulphuric acid c be se5 by comp>+ _! /ructural =mulas3 ,o -,,oh ,o -,,oh ,s ,s ,o -,,oh ,o -,,no#b ,! latt] may be reg>d$ z d]iv$ f ! =m] by ! sub/itution ( ! nitro gr\p 7,,no#b7 = ! hydroxyl gr\p 7,,oh74 ,illu/ration3 ,fig4 #dd ,! sulphuric acid plant4 ,fig4 #dd illu/rates ! simpl] p>ts ( a plant us$ 9 ! manufacture ( sulphuric acid by ! *amb] process4 ,sulphur or "s sulphide1 z ,fe,s#b1 is burn$ 9 furnace ,a4 ,! result+ sulphur dioxide1 toge!r ) air & "s nitrog5 p]oxide1 are conduct$ into ! l>ge *amb]s1 ! capacity ( ea* *amb] be+ ab\t #ge1jjj cu4 ft4 ,/eam is also admitt$ into ^! *amb]s at diff]5t po9ts4 ,^! comp\nds react to =m sulphuric acid1 accord+ to ! equations giv5 above4 ,! nitrog5 left aft] ! )drawal ( ! oxyg5 f ! admitt$ air escapes ?r\gh ! ,gay-,lussac t[] ,x4 ,9 ord] to prev5t ! escape ( ! oxides ( nitrog5 reg5]at$ 9 ! reaction1 ! t[] is fill$ ) lumps ( coke1 ov] :i* trickles conc5trat$ sulphuric acid admitt$ f ,y4 ,! nitrog5 p]oxide dissolves 9 ! acid & ! result+ solution collects 9 ,h4 ,?is is pump$ into ,e1 :]e x is mix$ ) dilute acid & all[$ to trickle d[n ?r\gh ! *amb] ,d 7,glov] t[]71 :i* is fill$ ) "s acid-resi/+ rock4 ,"h ! nitrog5 p]oxide is expell$ f ! solution by ! action ( ! hot gases ent]+ f ,a1 & toge!r ) !m ent]s ! fir/ *amb] aga94 ,! acid f :i* ! nitrog5 p]oxide is expell$ collects 9 ,f4 ,!oretically1 a small am\nt ( nitrog5 p]oxide w\ld suffice to prep>e an unlimit$ am\nt ( sulphuric acid2 practically1 "s ( x escapes1 & ?is is replac$ by small am\nts admitt$ at ,b4 ,! sulphuric acid s =m$1 toge!r ) ! excess ( cond5s$ /eam1 collect ^u ! floor ( ! *amb]s 9 ! =m ( a liquid conta9+ f #fb to #gj ( sulphuric acid4 ,! product is call$ *amb] acid & is q impure2 b = _m purposes1 su* z ! manufacture ( f]tiliz]s1 x ne$s no fur!r treatm5t4 ,x c be conc5trat$ by boil+ x 9 vessels made ( iron or plat9um1 :i* resi/ ! action ( ! acid1 ne>ly all ! wat] boil+ (f4 ,pure conc5trat$ acid c be made be/ by ! contact process1 :ile ! *amb] process is *eap] = ! dilute impure acid4 ,physical prop]ties4 ,sulphuric acid is a colorless1 oily liquid1 ne>ly twice z heavy z wat]4 ,! ord9>y conc5trat$ acid conta9s ab\t #b ( wat]1 has a d5sity ( #a4hd1 & boils at #cch4 ,x is sometimes call$ oil ( vitriol1 s9ce x 0 =m]ly made by di/ill+ a sub/ance call$ gre5 vitriol4 ,*emical prop]ties4 ,sulphuric acid possesses *emical prop]ties :i* make x "o ( ! mo/ important ( *emical sub/ances4 #a4 ,action z an acid4 ,9 dilute solution sulphuric acid acts z any o!r acid1 =m+ salts ) oxides & hydroxides4 #b4 ,action z an oxidiz+ ag5t4 ,sulphuric acid conta9s a l>ge p]c5tage ( oxyg5 & is1 l nitric acid1 a v good oxidiz+ ag5t4 ,:5 ! conc5trat$ acid is heat$ ) sulphur1 c>bon1 & _m o!r sub/ances1 oxidation takes place1 ! sulphuric acid decompos+ accord+ to ! equation ,h#b,,s#d ,h#b,,s#c ,o4 #c4 ,action on metals4 ,9 dilute solution sulphuric acid acts ^u _m metals1 su* z z9c1 =m+ a sulphate & lib]at+ hydrog54 ,:5 ! conc5trat$ acid is employ$ ! hydrog5 set free is oxidiz$ by a new portion ( ! acid1 ) ! lib]ation ( sulphur dioxide4 ,) copp] ! reactions are express$ by ! equations 7#a7 ,cu ,h#b,,s#d ,cu,s,o#d #b;,h1 7#b7 ,h#b,,s#d #b;,h ,h#b,,s#c ,h#b,o1 7#c7 ,h#b,,s#c ,h#b,o ,,s#b4 ,by comb9+ ^! equations ! foll[+ "o is obta9$3 ,cu #b;,h#b,,s#d ,cu,s,o#d ,,s#b #b;,h#b,o4 #d4 ,action on salts4 ,we h repeat$ly se5 t an acid ( high boil+ po9t heat$ ) ! salt ( "s acid ( l[] boil+ po9t w drive out ! l[ boil+ acid4 ,! boil+ po9t ( sulphuric acid 7#cch7 is high] ?an t ( almo/ any common acid2 h5ce x is us$ l>gely 9 ! prep>ation ( o!r acids4 #e4 ,action on wat]4 ,conc5trat$ sulphuric acid has a v great aff9ity = wat]1 & is !re=e an effective dehydrat+ ag5t4 ,gases :i* h no *emical action ^u sulphuric acid c be fre$ f wat] vapor by bubbl+ !m ?r\gh ! /rong acid4 ,:5 ! acid is dilut$ ) wat] mu* heat is set free1 & c>e mu/ be tak5 to keep ! liquid ?or\ghly /irr$ dur+ ! mix+1 & to p\r ! acid into ! wat]1--nev] ! rev]se4 ,n only c sulphuric acid absorb wat]1 b x w (t5 )draw ! elem5ts hydrog5 & oxyg5 f a comp\nd conta9+ !m1 decompos+ ! comp\nd1 & comb9+ ) ! wat] s =m$4 ,= ?is reason mo/ organic sub/ances1 su* z sug>1 wood1 cotton1 & wool5 fib]1 & ev5 fle%1 all ( :i* conta9 mu* oxyg5 & hydrog5 9 addition to c>bon1 are *>r$ or burn$ by ! action ( ! conc5trat$ acid4 ,salts ( sulphuric acid1--sulphates4 ,! sulphates =m a v important class ( salts1 & _m ( !m h comm]cial uses4 ,copp]as 7iron sulphate71 blue vitriol 7copp] sulphate71 & ,epsom salt 7magnesium sulphate7 s]ve z examples4 ,_m sulphates are important m9]als1 prom95t among ^! be+ gypsum 7calcium sulphate7 & b>ytes 7b>ium sulphate74 ,?iosulphuric acid 7,h#b,s#b,o#c72 ,?iosulphates4 ,_m o!r acids ( sulphur conta9+ oxyg5 are kn[n1 b none ( !m are ( great importance4 ,mo/ ( !m _c be prep>$ 9 a pure /ate1 & are kn[n only ?r\gh _! salts4 ,! mo/ important ( ^! is ?iosulphuric acid4 ,:5 sodium sulphite is boil$ ) sulphur ! two sub/ances comb9e1 =m+ a salt :i* has ! composition repres5t$ 9 ! =mula ,na#b,s#b,o#c3 ,na#b,,s#c ,s ,na#b,s#b,o#c4 ,! sub/ance is call$ sodium ?iosulphate1 & is a salt ( ! easily decompos$ acid ,h#b,s#b,o#c1 call$ ?iosulphuric acid4 ,?is reaction is q simil> to ! action ( oxyg5 ^u sulphites3 ,na#b,,s#c ,o ,na#b,,s#d4 ,m commonly ! salt is call$ sodium hyposulphite1 or m]ely hypo4 ,x is a :ite solid & is ext5sively us$ 9 photography1 9 ! blea*+ indu/ry1 & z a dis9fectant4 ,monobasic & dibasic acids4 ,su* acids z hydro*loric & nitric acids1 :i* h only "o replaceable hydrog5 atom 9 ! molecule1 or 9 o!r words yield "o hydrog5 ion 9 solution1 are call$ monobasic acids4 ,acids yield+ two hydrog5 ions 9 solution are call$ dibasic acids4 ,simil>ly1 we may h tribasic & tetrabasic acids4 ,! ?ree acids ( sulphur are dibasic acids4 ,x is !re=e possible = ea* ( !m to =m bo? normal & acid salts4 ,! acid salts c be made 9 two ways3 ! acid may be treat$ ) only half en\gh base to neutralize x1-- ,na,o,h ,h#b,,s#d ,na,h,s,o#d ,h#b,o2 or a normal salt may be treat$ ) ! free acid1-- ,na#b,,s#d ,h#b,,s#d #b,na,h,s,o#d4 ,acid sulphites & sulphides may be made 9 ! same ways4 ,c>bon disulphide 7,,cs#b74 ,:5 sulphur vapor is pass$ ov] highly heat$ c>bon ! two elem5ts comb9e1 =m+ c>bon disulphide 7,,cs#b71 j z oxyg5 & c>bon unite to =m c>bon dioxide 7,,co#b74 ,! sub/ance is a heavy1 colorless liquid1 possess+1 :5 pure1 a pleasant e!real odor4 ,on /&+ = "s "t1 especially :5 expos$ to sunlight1 x und]goes a slight decomposition & acquires a mo/ disagreeable1 rancid odor4 ,x has ! prop]ty ( dissolv+ _m sub/ances1 su* z gums1 res9s1 & waxes1 :i* are insoluble 9 mo/ liquids1 & x is ext5sively us$ z a solv5t = su* sub/ances4 ,x is also us$ z an insecticide4 ,x boils at a l[ temp]ature 7#df71 & its vapor is v inflammable1 burn+ 9 ! air to =m c>bon dioxide & sulphur dioxide1 accord+ to ! equation ,,cs#b #f,o ,,co#b #b,,s#b4 ,illu/ration3 ,fig4 #de ,comm]cial prep>ation ( c>bon disulphide4 ,9 ! prep>ation ( c>bon disulphide an electrical furnace is employ$1 su* z is repres5t$ 9 ,fig4 #de4 ,! furnace is pack$ ) c>bon ,c1 & ?is is f$ 9 ?r\gh ! hopp]s ,b1 z fa/ z t :i* is pres5t 9 ! he>? ( ! furnace is us$ up4 ,sulphur is introduc$ at ,a1 & at ! l[] ends ( ! tubes x is melt$ by ! heat ( ! furnace & fl[s into ! he>? z a liquid4 ,an electrical curr5t is pass$ ?r\gh ! c>bon & melt$ sulphur f ! electrodes ,e1 heat+ ! *>ge4 ,! vapors ( c>bon disulphide pass up ?r\gh ! furnace & escape at ,d1 f :i* !y pass to a suitable cond5s+ app>atus4 ,comp>ison ( sulphur & oxyg54 ,a comp>ison ( ! =mulas & ! *emical prop]ties ( correspond+ comp\nds ( oxyg5 & sulphur br+s to light _m /rik+ simil>ities4 ,! conduct ( hydrosulphuric acid & wat] t[>d _m sub/ances has be5 se5 to be v simil>2 ! oxides & sulphides ( ! metals h analog\s =mulas & und]go _m p>allel reactions4 ,c>bon dioxide & disulphide are prep>$ 9 simil> ways & und]go _m analog\s reactions4 ,x is cle>1 !re=e1 t ^! two elem5ts are f> m closely relat$ to ea* o!r ?an to any ( ! o!r elem5ts s f> /udi$4 ,sel5ium & tellurium4 ,^! two v uncommon elem5ts are /ill m closely relat$ to sulphur ?an is oxyg54 ,!y occur 9 comp>atively small quantities & are usually f\nd associat$ ) sulphur & sulphides1 ei!r z ! free elem5ts or m commonly 9 comb9ation ) metals4 ,!y =m comp\nds ) hydrog5 ( ! =mulas ,h#b,se & ,h#b,te2 ^! bodies are gases ) prop]ties v simil> to ^? ( ,h#b,s4 ,!y also =m oxides & oxyg5 acids :i* resemble ! correspond+ sulphur comp\nds4 ,! elem5ts ev5 h allotropic =ms correspond+ v closely to ^? ( sulphur4 ,tellurium is sometimes f\nd 9 comb9ation ) gold & copp]1 & occasions "s difficulties 9 ! ref9+ ( ^! metals4 ,! elem5ts h v few practical applications4 ,cry/allography4 ,9 ord] to und]/& ! diff]5ce betwe5 ! two k9ds ( sulphur cry/als1 x is necess>y to "k some?+ ab\t cry/als 9 g5]al & ! =ms :i* !y may assume4 ,an exam9ation ( a l>ge numb] ( cry/als has %[n t al?\gh !y may diff] mu* 9 geometric =m1 !y c all be consid]$ z modifications ( a few simple plans4 ,! be/ way to und]/& ! relation ( "o cry/al to ano!r is to look ^u e cry/al z hav+ its faces & angles arrang$ 9 def9ite fa%ion ab\t c]ta9 imag9>y l9es drawn ?r\gh ! cry/al4 ,^! l9es are call$ axes1 & be> mu* ! same relation to a cry/al z d ! axis & p>allels ( latitude & longitude to ! e>? & a geographical /udy ( x4 ,all cry/als c be ref]r$ to "o ( six simple plans or sy/ems1 :i* h _! axes z %[n 9 ! foll[+ draw+s4 ,! names & *>act]i/ics ( ^! sy/ems are z foll[s3 #a4 ,isometric or regul> sy/em 7,fig4 #df74 ,?ree equal axes1 all at "r angles4 ,illu/ration3 ,fig4 #df #b4 ,tetragonal sy/em 7,fig4 #dg74 ,two equal axes & "o ( diff]5t l5g?1 all at "r angles to ea* o!r4 ,illu/ration3 ,fig4 #dg #c4 ,or?orhombic sy/em 7,fig4 #dh74 ,?ree unequal axes1 all at "r angles to ea* o!r4 ,illu/ration3 ,fig4 #dh #d4 ,monocl9ic sy/em 7,fig4 #di74 ,two axes at "r angles1 & a ?ird at "r angles to "o ( ^!1 b incl9$ to ! o!r4 ,illu/ration3 ,fig4 #di #e4 ,tricl9ic sy/em 7,fig4 #ej74 ,?ree axes1 all incl9$ to ea* o!r4 ,illu/ration3 ,fig4 #ej #f4 ,hexagonal sy/em 7,fig4 #ea74 ,?ree equal axes 9 ! same plane int]sect+ at angles ( #fj1 & a f\r? at "r angles to all ( ^!4 ,illu/ration3 ,fig4 #ea ,e cry/al c be imag9$ to h its faces & angles arrang$ 9 a def9ite way ar\nd "o ( ^! sy/ems ( axes4 ,a cube1 = in/ance1 is ref]r$ to ,plan #a1 an axis end+ 9 ! c5t] ( ea* face2 :ile 9 a regul> octoh$ron an axis ends 9 ea* solid angle4 ,^! =ms are %[n 9 ,fig4 #df4 ,x w be se5 t bo? ( ^! figures belong to ! same sy/em1 ?\gh !y are v diff]5t 9 appe>ance4 ,9 ! same way1 _m geometric =ms may be d]iv$ f ea* ( ! sy/ems1 & ! light l9es ab\t ! axes 9 ! draw+s %[ two ( ! simple/ =ms ( ea* ( ! sy/ems4 ,9 g5]al a giv5 sub/ance always cry/allizes 9 ! same sy/em1 & two correspond+ faces ( ea* cry/al ( x always make ! same angle ) ea* o!r4 ,a few sub/ances1 ( :i* sulphur is an example1 cry/allize 9 two diff]5t sy/ems1 & ! cry/als diff] 9 su* physical prop]ties z melt+ po9t & d5sity4 ,su* sub/ances are said to be dimorph\s4 ,,ex]cises #a4 7a7 ,w\ld ! same am\nt ( heat be g5]at$ by ! combu/ion ( #a g4 ( ea* ( ! allotropic modifications ( sulphur8 7b7 ,w\ld ! same am\nt ( sulphur dioxide be =m$ 9 ea* case8 #b4 ,is ! equation = ! prep>ation ( hydrosulphuric acid a rev]sible "o8 ,z ord9>ily c>ri$ out1 does ! reaction complete itself8 #c4 ,suppose t hydrosulphuric acid 7 a liquid1 w\ld x be necess>y to modify ! me?od ( prep>ation8 #d4 ,c sulphuric acid be us$ to dry hydrosulphuric acid8 ,give reason = answ]4 #e4 ,does dry hydrosulphuric acid react ) litmus pap]8 ,/ate reason = answ]4 #f4 ,h[ _m grams ( iron sulphide are necess>y to prep>e #ajj l4 ( hydrosulphuric acid :5 ! laboratory conditions are #ag & #gdj mm4 pressure8 #g4 ,suppose t ! hydrog5 9 #a l4 ( hydrosulphuric acid 7 lib]at$2 :at volume w\ld x occupy1 ! gases be+ measur$ "u ! same conditions8 #h4 ,write ! equations repres5t+ ! reaction betwe5 hydrosulphuric acid & sodium hydroxide & ammonium hydroxide respectively4 #i4 ,%[ t ! prep>ation ( sulphur dioxide f a sulphite is simil> 9 pr9ciple to ! prep>ation ( hydrog5 sulphide4 #aj4 7a7 ,does dry sulphur dioxide react ) litmus pap]8 7b7 ,h[ c x be %[n t a solution ( sulphur dioxide 9 wat] acts l an acid8 #aa4 7a7 ,calculate ! p]c5tage composition ( sulphur\s anhydride & sulphuric anhydride4 7b7 ,%[ h[ ^! two sub/ances are 9 h>mony ) ! law ( multiple proportion4 #ab4 ,h[ _m p\nds ( sulphur w\ld be necess>y 9 ! prep>ation ( #ajj lb4 ( #ih sulphuric acid8 #ac4 ,:at weight ( sulphur dioxide is necess>y 9 ! prep>ation ( #a kg4 ( sodium sulphite8 #ad4 ,:at weight ( copp] sulphate cry/als c be obta9$ by dissolv+ #a kg4 ( copp] 9 sulphuric acid & cry/alliz+ ! product f wat]8 #ae4 ,write ! names & =mulas ( ! oxides & oxyg5 acids ( sel5ium & tellurium4 #af4 ,9 ! comm]cial prep>ation ( c>bon disulphide1 :at is ! function ( ! electric curr5t8 #ag4 ,if ! ,gay-,lussac t[] 7 omitt$ f ! sulphuric acid factory1 :at effect w\ld ?is h on ! co/ ( production ( sulphuric acid8 ,,*apt] ,,xv ,,p]iodic ,,law ,a numb] ( ! elem5ts h n[ be5 /udi$ some:at closely4 ,! fir/ ?ree ( ^!1 oxyg51 hydrog51 & nitrog51 :ile hav+ "s physical prop]ties 9 common ) ea* o!r1 h almo/ no po9t ( simil>ity z reg>ds _! *emical conduct4 ,on ! o!r h&1 oxyg5 & sulphur1 :ile q diff]5t physically1 h mu* 9 common 9 _! *emical prop]ties4 ,ab\t eighty elem5ts are n[ kn[n4 ,if all ( ^! %\ld h prop]ties z div]se z d oxyg51 hydrog51 & nitrog51 ! /udy ( *emi/ry w\ld pla9ly be a v difficult & complicat$ "o4 ,if1 h[ev]1 ! elem5ts c be classifi$ 9 gr\ps1 ! memb]s ( :i* h v simil> prop]ties1 ! /udy w be v mu* simplifi$4 ,e>li] classification ( ! elem5ts4 ,ev5 at an e>ly p]iod ef=ts 7 made to discov] "s natural pr9ciple 9 accordance ) :i* ! elem5ts c\ld be classifi$4 ,two ( ^! classifications may be m5tion$ "h4 #a4 ,classification into metals & non-metals4 ,! classification into metals & non-metals mo/ naturally sugge/$ itself4 ,?is gr\p+ 0 bas$ l>gely on physical prop]ties1 ! metals be+ heavy1 lu/r\s1 malleable1 ductile1 & good conductors ( heat & electricity4 ,elem5ts possess+ ^! prop]ties are usually base-=m+ 9 "*1 & ! ability to =m bases came to be reg>d$ z a *>act]i/ic prop]ty ( ! metals4 ,! non-metals possess$ physical prop]ties :i* 7 ! rev]se ( ^? ( ! metals1 & 7 acid-=m+ 9 "*4 ,n mu* 0 ga9$ by ?is classification1 & x 0 v imp]fect4 ,"s metals1 su* z potassium1 are v light2 "s non-metals1 su* z iod9e1 h a high lu/]2 "s elem5ts c =m ei!r an acid or a base4 #b4 ,classification into triad families4 ,9 #ahbe ,db]e9] obs]v$ t an int]e/+ relation exi/s betwe5 ! atomic weights ( *emically simil> elem5ts4 ,to illu/rate1 li?ium1 sodium1 & potassium resemble ea* o!r v closely1 & ! atomic weight ( sodium is almo/ exactly an ari?metical mean betwe5 ^? ( ! o!r two3 7#g4jc #ci4ae7_/b #bc4ji4 ,9 _m *emical & physical prop]ties sodium is midway betwe5 ! o!r two4 ,a numb] ( triad families 7 f\nd1 b among eighty elem5ts1 ^: atomic weights range all ! way f #a to #bdj1 su* agreem5ts might be m]e *ance4 ,moreov] _m elem5ts did n appe> to belong to su* families4 ,p]iodic division4 ,9 #ahfi ! ,russian *emi/ ,m5deleff devis$ an arrangem5t ( ! elem5ts bas$ on _! atomic weights1 :i* has prov$ to be ( great s]vice 9 ! comp>ative /udy ( ! elem5ts4 ,a few mon?s lat] ! ,g]man1 ,lo?> ,mey]1 indep5d5tly sugge/$ ! same ideas4 ,?is arrangem5t br\ght to light a great g5]alization1 n[ kn[n z ! p]iodic law4 ,an exact /atem5t ( ! law w be giv5 aft] ! me?od ( arrang+ ! elem5ts has be5 describ$4 ,illu/ration3 ,,dmitri ,,ivanovit* ,,m5del,,eff 7,russian7 7#ahcd-aijg7 ,au?or ( ! p]iodic law2 made _m inve/igations on ! physical con/ants ( elem5ts & comp\nds2 wrote an important book entitl$ ,pr9ciples ( ,*emi/ry2 univ]sity pr(essor & gov]nm5t (ficial ,arrangem5t ( ! p]iodic table4 ,! arrangem5t sugge/$ by ,m5deleff1 modifi$ some:at by m rec5t inve/igations1 is z foll[s3 ,beg9n+ ) li?ium1 :i* has an atomic weight ( #g1 ! elem5ts are arrang$ 9 a horizontal r[ 9 ! ord] ( _! atomic weights1 ?us3 ,li 7#g4jc71 ,be 7#i4a71 ,b 7#aa71 ,c 7#ab71 ,n 7#ad4jd71 ,o 7#af71 ,f 7#ai74 ,^! sev5 elem5ts all diff] m>k$ly f ea* o!r4 ,! eigh? elem5t1 sodium1 is v simil> to li?ium4 ,x is plac$ j "u li?ium1 & a new r[ foll[s3 ,na7#bc4je71 ,mg 7#bd4cf71 ,al 7#bg4a71 ,si 7#bh4d71 ,p 7#ca71 ,s 7#cb4jf71 ,cl7#ce4de74 ,:5 ! fifte5? elem5t1 potassium1 is rea*$1 x is plac$ "u sodium1 to :i* x is v simil>1 & s]ves to beg9 a ?ird r[3 ,k 7#ci4ae71 ,ca 7#dj4a71 ,sc 7#dd4a17 ,ti 7#dh4a71 ,v 7#ea4b71 ,cr 7#eb4a71 ,mn7#ee74 ,n only is !re a /rong simil>ity betwe5 li?ium1 sodium1 & potassium1 :i* h be5 plac$ 9 a v]tical r[ because ( ?is resemblance1 b ! elem5ts 9 ! o!r v]tical r[s exhibit mu* ( ! same k9d ( simil>ity among !mselves1 & evid5tly =m little natural gr\ps4 ,! ?ree elem5ts foll[+ manganese1 namely1 iron1 nickel1 & cobalt1 h atomic weights ne> toge!r1 & are v simil> *emically4 ,!y d n /rongly resemble any ( ! elem5ts s f> consid]$1 & are accord+ly plac$ 9 a gr\p by !mselves1 foll[+ manganese4 ,a new r[ is begun ) copp]1 :i* some:at resembles ! elem5ts ( ! fir/ v]tical column4 ,foll[+ ! fif? & sev5? r[s are gr\ps ( ?ree closely relat$ elem5ts1 s t ! complet$ arrangem5t has ! appe>ance repres5t$ 9 ! table on page #afh4 ,,! ,,p]iodic ,,arrangem5t ,,( ,,! ,,elem5ts ---------------------------------------- ----------------------- ,p]iods ,,gr\p ,,gr\p ,,gr\p ,,gr\p ,,gr\p #j ,i ,,ii ,,iii ,,iv ,a ,b,a ,b,a ,b,a ,b,a ,b ---------------------------------------- ----------------------- #a ,h#a4jjh #b ,he#d ,li#g4jc ,be#i4a ,b#aa ,c#ab ---------------------------------------- ----------------------- #c ,ne#bj,na#bc4je ,mg#bd4cf ,,al#bg4a ,si#bh4d ---------------------------------------- ----------------------- #d ,a#ci4i ,k#ci4ae ,ca#dj4a ,sc#dd4a ,ti#dh4a ---------------------------------------- ----------------------- #e ,cu#fc4f ,zn#fe4d ,ga#gj ,ge#gb4e ---------------------------------------- ----------------------- #f ,kr#ha4h ,rb#he4e ,sr#hg4f ,y#hi ,zr#ij4f ---------------------------------------- ----------------------- #g ,ag#ajg4ic ,cd#aab4d ,9#aae ,sn#aai ---------------------------------------- ----------------------- #h ,x#abh ,cs#acb4i ,ba#acg4d ,la#ach4i ,ce,yb99 #adj4be-agc ---------------------------------------- ----------------------- #i ,au#aig4b ,hg#bjj ,tl#bjd4a ,pb#bjf4i ,bi#bjh4e ---------------------------------------- ----------------------- #aj ,ra#bbe ,?#bcb4e ---------------------------------------- ----------------------- ,r#b,o ,,ro ,r#b,o#c ,,ro#b ,,rh ,,rh#b ,,rh#c ,,rh#d ---------------------------------------- ----------------------- "p #b ---------------------------------------- ------------ ,p]iods ,,gr\p ,,gr\p ,,gr\p ,,gr\p ,v ,,vi ,,vii ,,viii ,a ,b,a ,b,a ,b ---------------------------------------- ------------ #a #b ,n#ad4jd ,o#af ,f#ai ---------------------------------------- ------------ #c ,p#ca ,s#cb4jf ,cl#ce4de ---------------------------------------- ------------ #d ,v#ea4b ,cr#eb4a ,mn#ee ,fe#ee4i ,ni#eh4g ,co#ei ---------------------------------------- ------------ #e ,z#ge ,se#gi4b ,br#gi4if ---------------------------------------- ------------ #f ,cb#id ,mo#if ,ru#aja4g ,rh#ajc ,pd#ajf4e ---------------------------------------- ------------ #g ,sb#abj4b ,te#abg4f ,i#abf4ig ---------------------------------------- ------------ #h ,ta#ahc ,w#ahd ,os#aia ,ir#aic ,pt#aid4h ---------------------------------------- ------------ #i ---------------------------------------- ------------ #aj ,u#bch4e ---------------------------------------- ------------ ,r#b,o#e ,,ro#c ,r#b,o#g ,,ro#d ,,rh#c ,,rh#b ,,rh ---------------------------------------- ------------ 99 ,?is includes a numb] ( elem5ts ^: atomic weights lie betwe5 #adj & #agc1 b :i* h n be5 accurately /udi$1 & s _! prop] arrangem5t is unc]ta94 ,place ( ! atmosph]ic elem5ts4 ,:5 argon 0 discov]$ x 0 se5 at once t !re 0 no place 9 ! table = an elem5t ( atomic weight approximately #dj4 ,:5 ! o!r inactive elem5ts 7 f\nd1 h[ev]1 x became app>5t t !y =m a gr\p j prec$+ ,gr\p #a4 ,!y are accord+ly arrang$ 9 ?is way 9 ,gr\p #j 7see table on opposite page74 ,a /udy ( ?is table br+s to light c]ta9 v /rik+ facts4 ,prop]ties ( elem5ts v>y ) atomic weights4 ,!re is evid5tly a close relation betwe5 ! prop]ties ( an elem5t & its atomic weight4 ,li?ium1 at ! beg9n+ ( ! fir/ gr\p1 is a v /rong base-=m+ elem5t1 ) pron\nc$ metallic prop]ties4 ,b]yllium1 foll[+ li?ium1 is less /rongly base-=m+1 :ile boron has "s base-=m+ & "s acid-=m+ prop]ties4 ,9 c>bon all base-=m+ prop]ties h disappe>$1 & ! acid-=m+ prop]ties are m m>k$ ?an 9 boron4 ,^! become /ill m emphasiz$ z we pass ?r\gh nitrog5 & oxyg51 until on rea*+ fluor9e we h "o ( ! /ronge/ acid-=m+ elem5ts4 ,! prop]ties ( ^! sev5 elem5ts !re=e v>y regul>ly ) _! atomic weights1 or1 9 ma!matical language1 are regul> functions ( !m4 ,p]iodic law4 ,! prop]ties ( ! fir/ sev5 elem5ts v>y cont9u\sly--t is /eadily--away f base-=m+ & t[>d acid-=m+ prop]ties4 ,if li?ium _h ! smalle/ atomic weight ( any ( ! elem5ts1 & fluor9e ! greate/1 s t 9 pass+ f "o to ! o!r we _h includ$ all ! elem5ts1 we c\ld say t ! prop]ties ( elem5ts are cont9u\s functions ( _! atomic weights4 ,b fluor9e is an elem5t ( small atomic weight1 & ! "o foll[+ x1 sodium1 breaks ! regul> ord]1 = 9 x reappe> all ! *>act]i/ic prop]ties ( li?ium4 ,magnesium1 foll[+ sodium1 be>s mu* ! same relation to b]yllium t sodium does to li?ium1 & ! prop]ties ( ! elem5ts 9 ! second r[ v>y mu* z !y d 9 ! fir/ r[ until potassium is rea*$1 :5 ano!r repetition beg9s4 ,! prop]ties ( ! elem5ts d n v>y cont9u\sly1 !re=e1 ) atomic weights1 b at regul> int]vals !re is a repetition1 or p]iod4 ,?is g5]alization is kn[n z ! p]iodic law1 & may be /at$ ?us3 ,! prop]ties ( elem5ts are p]iodic functions ( _! atomic weights4 ,! two families 9 a gr\p4 ,:ile all ! elem5ts 9 a giv5 v]tical column be> a g5]al resemblance to ea* o!r1 x has be5 notic$ t ^? belong+ to p]iods hav+ ev5 numb]s are v /rik+ly simil> to ea* o!r4 ,!y are plac$ at ! left side ( ! gr\p columns4 ,9 l mann]1 ! elem5ts belong+ to ! odd p]iods are v simil> & are arrang$ at ! "r side ( ! gr\p columns4 ,?us calcium1 /rontium1 & b>ium are v mu* alike2 s1 too1 are magnesium1 z9c1 & cadmium4 ,! resemblance betwe5 calcium & magnesium1 or /rontium & z9c1 is mu* less m>k$4 ,?is me?od ( arrangem5t !re=e divides ea* gr\p into two families1 ea* conta9+ f\r or five memb]s1 betwe5 :i* !re is a great simil>ity4 ,family resemblances4 ,let u n[ inquire m closely 9 :at respects ! elem5ts ( a family resemble ea* o!r4 #a4 ,val5ce4 ,9 g5]al ! val5ce ( ! elem5ts 9 a family is ! same1 & ! =mulas ( _! comp\nds are !re=e simil>4 ,if we "k t ! =mula ( sodium *loride is ,na,cl1 x is pretty c]ta9 t ! =mula ( potassium *loride w be ,k,cl--n ,k,cl#b or ,k,cl#c4 ,! g5]al =mulas ,r#b,o1 ,,ro1 etc41 plac$ bel[ ! columns %[ ! =mulas ( ! oxides ( ! elem5ts 9 ! column provid$ !y =m oxides4 ,9 l mann] ! =mulas ,,rh1 ,,rh#b1 etc41 %[ ! composition ( ! comp\nds =m$ ) hydrog5 or *lor9e4 #b4 ,*emical prop]ties4 ,! *emical prop]ties ( ! memb]s ( a family are q simil>4 ,if "o memb] is a metal1 ! o!rs usually are2 if "o is a non-metal1 s1 too1 are ! o!rs4 ,! families 9 ! fir/ two columns consi/ ( metals1 :ile ! elem5ts f\nd 9 ! la/ two columns =m acids4 ,!re is 9 addition a c]ta9 regul>ity 9 prop]ties ( ! elem5ts 9 ea* family4 ,if ! elem5t at ! head ( ! family is a /rong acid-=m+ elem5t1 ?is prop]ty is likely to dim9i% gradually1 z we pass to ! memb]s ( ! family ) high] atomic weights4 ,?us phosphorus is /rongly acid-=m+1 ars5ic less s1 antimony /ill less s1 :ile bismu? has almo/ no acid-=m+ prop]ties4 ,we %all meet ) _m illu/rations ( ?is fact4 #c4 ,physical prop]ties4 ,9 ! same way1 ! physical prop]ties ( ! memb]s ( a family are 9 g5]al some:at simil>1 & %[ a regul> gradation z we pass f elem5t to elem5t 9 ! family4 ,?us ! d5sities ( ! memb]s ( ! magnesium family are ,mg #a4ge1 ,zn #g4jj1 ,cd #h4fg1 ,hg #ac4f4 ,_! melt+ po9ts are ,mg #gej1 ,zn #dbj1 ,cd #cbj1 ,hg -#ci4e4 ,value ( ! p]iodic law4 ,! p]iodic law has prov$ ( mu* value 9 ! developm5t ( ! sci5ce ( *emi/ry4 #a4 ,x simplifies /udy4 ,x is at once evid5t t su* regul>ities v mu* simplify ! /udy ( *emi/ry4 ,a ?or\gh /udy ( "o elem5t ( a family makes ! /udy ( ! o!r memb]s a mu* easi] task1 s9ce s _m ( ! prop]ties & *emical reactions ( ! elem5ts are simil>4 ,?us1 hav+ /udi$ ! elem5t sulphur 9 "s detail1 x is n necess>y to /udy sel5ium & tellurium s closely1 = mo/ ( _! prop]ties c be pr$ict$ f ! relation :i* !y su/a9 to sulphur4 #b4 ,x pr$icts new elem5ts4 ,:5 ! p]iodic law 0 fir/ =mulat$ !re 7 a numb] ( vacant places 9 ! table :i* evid5tly belong$ to elem5ts at t "t unkn[n4 ,f _! position 9 ! table1 ,m5deleff pr$ict$ ) great precision ! prop]ties ( ! elem5ts :i* he felt sure w\ld "o day be discov]$ to fill ^! places4 ,?ree ( !m1 sc&ium1 g]manium1 & gallium1 7 f\nd )9 fifte5 ye>s1 & _! prop]ties agre$ 9 a rem>kable way ) ! pr$ictions ( ,m5deleff4 ,!re are /ill "s vacant places 9 ! table1 especially among ! heavi] elem5ts4 #c4 ,x corrects errors4 ,! physical con/ants ( _m ( ! elem5ts did n at fir/ agree ) ^? dem&$ by ! p]iodic law1 & a fur!r /udy ( _m su* cases %[$ t errors _h be5 made4 ,! law has !re=e done mu* s]vice 9 indicat+ probable error4 ,imp]fections ( ! law4 ,!re /ill rema9 a good _m features :i* mu/ be reg>d$ z imp]fections 9 ! law4 ,mo/ conspicu\s is ! fact t ! elem5t hydrog5 has no place 9 ! table4 ,9 "s ( ! gr\ps elem5ts appe> 9 "o ( ! families1 :ile all ( _! prop]ties %[ t !y belong 9 ! o!r4 ,?us sodium belongs ) li?ium & n ) copp]2 fluor9e belongs ) *lor9e & n ) manganese4 ,!re are two in/ances :]e ! elem5ts mu/ be transpos$ 9 ord] to make !m fit into _! prop] gr\p4 ,accord+ to _! atomic weights1 tellurium %\ld foll[ iod9e1 & argon %\ld foll[ potassium4 ,_! prop]ties %[ 9 ea* case t ?is ord] mu/ be rev]s$4 ,! table sep>ates "s elem5ts altoge!r :i*1 9 _m respects h closely agree+ prop]ties4 ,iron1 *romium1 & manganese are all 9 diff]5t gr\ps1 al?\gh !y are simil> 9 _m respects4 ,! sy/em is !re=e to be reg>d$ z b a p>tial & imp]fect expression ( "s v important & fundam5tal relation betwe5 ! sub/ances :i* we "k z elem5ts1 ! exact nature ( ?is relation be+ z yet n completely cle> to u4 ,,ex]cises #a4 ,suppose t an elem5t 7 discov]$ t fill$ ! blank 9 ,gr\p ,o1 ,p]iod #e2 :at prop]ties w\ld x probably h8 #b4 ,suppose t an elem5t 7 discov]$ t fill$ ! blank 9 ,gr\p ,,vi1 ,p]iod #i1 family ,b2 :at prop]ties w\ld x h8 #c4 ,sulphur & oxyg5 bo? belong 9 ,gr\p ,,vi1 al?\gh 9 diff]5t families2 9 :at respects are ! two simil>8 ,,*apt] ,,xvi ,,! ,,*lor9e ,,family ,,atomic ,,melt+ ,,boil+ ,,color ,,& ,,/ate ,,weight ,,po9t ,,po9t ,fluor9e 7,f7 #ai4jj -#bbc -#ahg ,pale yell[i% gas4 ,*lor9e 7,cl7 #ce4de -#ajb -#cc4f ,gre5i%-yell[ gas4 ,brom9e 7,br7 #gi4if -#g #ei ,r$ liquid4 ,iod9e 7,i7 #abf4ig #ajg #age ,purpli%-black solid4 ,! family4 ,! f\r elem5ts nam$ 9 ! above table =m a /rongly m>k$ family ( elem5ts & illu/rate v cle>ly ! way 9 :i* ! memb]s ( a family 9 a p]iodic gr\p resemble ea* o!r1 z well z ! "* ( ! diff]5ces :i* we may expect to f9d betwe5 ! individual memb]s4 #a4 ,occurr5ce4 ,^! elem5ts d n occur 9 nature 9 ! free /ate4 ,! comp\nds ( ! la/ ?ree elem5ts ( ! family are f\nd ext5sively 9 sea wat]1 & on ?is acc\nt ! "n halog5s1 signify+ produc]s ( sea salt1 is sometimes appli$ to ! family4 #b4 ,prop]ties4 ,z w be se5 by ref]5ce to ! table1 ! melt+ po9ts & boil+ po9ts ( ! elem5ts ( ! family increase ) _! atomic weights4 ,a some:at simil> gradation is not$ 9 _! color & /ate4 ,"o atom ( ea* ( ! elem5ts comb9es ) "o atom ( hydrog5 to =m acids1 :i* are gases v soluble 9 wat]4 ,! aff9ity ( ! elem5ts = hydrog5 is 9 ! inv]se ord] ( _! atomic weights1 fluor9e hav+ ! /ronge/ aff9ity & iod9e ! weake/4 ,only *lor9e & iod9e =m oxides1 & ^? ( ! =m] elem5t are v un/able4 ,! elem5ts ( ! gr\p are unival5t 9 _! comp\nds ) hydrog5 & ! metals4 ,,fluor9e ,occurr5ce4 ,! elem5t fluor9e occurs 9 nature mo/ abundantly z ! m9]al fluorsp> 7,ca,f#b71 z cryolite 7,na#c;,al,f#f71 & 9 ! complex m9]al apatite 7#c ,ca#c7,,po#d7b;,ca,f#b74 ,prep>ation4 ,all attempts to isolate ! elem5t result$ 9 failure until rec5t ye>s4 ,me?ods simil> to ^? :i* succe$ 9 ! prep>ation ( ! o!r elem5ts ( ! family _c be us$2 = z soon z ! fluor9e is lib]at$ x comb9es ) ! mat]ials ( :i* ! app>atus is made or ) ! hydrog5 ( ! wat] :i* is always pres5t4 ,! prep>ation ( fluor9e 0 f9ally accompli%$ by ! ,fr5* *emi/ ,moissan by ! electrolysis ( hydr(luoric acid4 ,p]fectly dry hydr(luoric acid 7,,hf7 0 cond5s$ to a liquid & plac$ 9 a ,u-%ap$ tube made ( plat9um 7or copp]71 :i* 0 furni%$ ) electrodes & deliv]y tubes1 z %[n 9 ,fig4 #eb4 ,?is liquid is n an electrolyte1 b becomes su* :5 potassium fluoride is dissolv$ 9 x4 ,:5 ?is solution 0 electrolyz$ hydrog5 0 set free at ! ca?ode & fluor9e at ! anode4 ,illu/ration3 ,fig4 #eb ,prop]ties4 ,fluor9e is a gas ( slightly yell[i% color1 & c be cond5s$ to a liquid boil+ at -#ahg "u atmosph]ic pressure4 ,x solidifies at -#bbc4 ,x is extremely active *emically1 be+ ! mo/ active ( all ! elem5ts at ord9>y temp]atures4 ,x comb9es ) all ! common elem5ts save oxyg51 v (t5 ) inc&esc5ce & ! lib]ation ( mu* heat4 ,x has a /rong aff9ity = hydrog5 & is able to )draw x f its comp\nds ) o!r elem5ts4 ,because ( its great activity x is extremely poison\s4 ,fluor9e does n =m any oxides1 nei!r does x =m any oxyg5 acids1 9 :i* respects x diff]s f ! o!r memb]s ( ! family4 ,hydr(luoric acid 7,,hf74 ,hydr(luoric acid is readily obta9$ f fluorsp> by ! action ( conc5trat$ sulphuric acid4 ,! equation is ,ca,f#b ,h#b,,s#d ,ca,s,o#d #b;,,hf4 ,9 its physical prop]ties x resembles ! b9>y acids ( ! o!r elem5ts ( ?is family1 be+1 h[ev]1 m easily cond5s$ to a liquid4 ,! anhydr\s acid boils at #ai & c !re=e be prep>$ at ord9>y pressures4 ,x is soluble 9 all proportions 9 wat]1 & a conc5trat$ solution--ab\t #ej--;is prep>$ = ! m>ket4 ,its fumes are exce$+ly irritat+ to ! respiratory organs1 & sev]al *emi/s h lo/ _! lives by accid5tally brea?+ !m4 ,illu/ration3 ,,h5ri ,,moissan 7,fr5*7 7#ahec-aijg7 ,fam\s = 8 "w ) ! electric furnace at high temp]atures2 prep>$ artificial diamonds1 toge!r ) _m new b9>y comp\nds su* z c>bides1 silicides1 borides1 & nitrides2 isolat$ fluor9e & /udi$ its prop]ties & its comp\nds v ?or\ghly ,*emical prop]ties4 ,hydr(luoric acid1 l o!r /rong acids1 readily acts on bases & metallic oxides & =ms ! correspond+ fluorides4 ,x also dissolves c]ta9 metals su* z silv] & copp]4 ,x acts v vigor\sly ^u organic matt]1 a s+le drop ( ! conc5trat$ acid mak+ a sore on ! sk9 :i* is v pa9ful & sl[ 9 heal+4 ,its mo/ *>act]i/ic prop]ty is its action ^u silicon dioxide 7,si,o#b71 ) :i* x =ms wat] & ! gas silicon tetrafluoride 7,si,f#d71 z %[n 9 ! equation ,si,o#b #d;,,hf ,si,f#d #b;,h#b,o4 ,glass consi/s ( c]ta9 comp\nds ( silicon1 :i* are likewise act$ on by ! acid s t x _c be kept 9 glass bottles4 ,x is pres]v$ 9 flasks made ( wax or gutta-p]*a4 ,et*+4 ,advantage is tak5 ( ?is reaction 9 et*+ designs ^u glass4 ,! glass vessel is pa9t$ ov] ) a protective pa9t ^u :i* ! acid w n act1 ! p>ts :i* x is desir$ to make opaque be+ left unprotect$4 ,a mixture ( fluorsp> & sulphuric acid is !n pa9t$ ov] ! vessel & aft] a few m9utes ! vessel is wa%$ clean4 ,:]ev] ! hydr(luoric acid comes 9 contact ) ! glass x acts ^u x1 de/roy+ its lu/] & mak+ x opaque1 s t ! expos$ design w be et*$ ^u ! cle> glass4 ,fro/$ glass globes are (t5 made 9 ?is way4 ,! et*+ may also be effect$ by cov]+ ! glass ) a ?9 lay] ( p>aff91 cutt+ ! design ?r\gh ! wax & !n expos+ ! glass to ! fumes ( ! acid4 ,salts ( hydr(luoric acid1--fluorides4 ,a numb] ( ! fluorides are kn[n1 b only "o ( !m1 calcium fluoride 7,ca,f#b71 is ( importance4 ,?is is ! well-kn[n m9]al fluorsp>4 ,,*lor9e ,hi/orical4 ,:ile /udy+ ! action ( hydro*loric acid ^u ! m9]al pyrolusite1 9 #aggd1 ,s*eele obta9$ a yell[i%1 gase\s sub/ance to :i* he gave a "n 9 keep+ ) ! phlogi/on !ory !n curr5t4 ,lat] x 0 suppos$ to be a comp\nd conta9+ oxyg54 ,9 #ahaj1 h[ev]1 ! ,engli% *emi/ ,sir ,humphry ,davy prov$ x to be an elem5t & nam$ x *lor9e4 ,occurr5ce4 ,*lor9e does n occur free 9 nature1 b its comp\nds are widely di/ribut$4 ,= ! mo/ "p x occurs 9 comb9ation ) ! metals 9 ! =m ( *lorides1 ^? ( sodium1 potassium1 & magnesium be+ mo/ abundant4 ,ne>ly all salt wat] conta9s ^! sub/ances1 p>ticul>ly sodium *loride1 & v l>ge salt b$s consi/+ ( *lorides are f\nd 9 _m p>ts ( ! _w4 ,prep>ation4 ,two g5]al me?ods ( prep>+ *lor9e may be m5tion$1 namely1 ! laboratory me?od & ! electrolytic me?od4 #a4 ,laboratory me?od4 ,9 ! laboratory *lor9e is made by w>m+ ! m9]al pyrolusite 7manganese dioxide1 ,mn,o#b7 ) conc5trat$ hydro*loric acid4 ,! fir/ reaction1 :i* seems to be simil> to ! action ( acids ^u oxides 9 g5]al1 is express$ 9 ! equation ,mn,o#b #d;,h,cl ,mn,cl#d #b;,h#b,o4 ,! manganese comp\nd s =m$ is v un/able1 h[ev]1 & breaks cl[n accord+ to ! equation ,mn,cl#d ,mn,cl#b #b;,cl4 ,in/ead ( us+ hydro*loric acid 9 ! prep>ation ( *lor9e x w s]ve j z well to use a mixture ( sodium *loride & sulphuric acid1 s9ce ^! two react to =m hydro*loric acid4 ,! foll[+ equations w !n express ! *anges3 7#a7 #b,na,cl ,h#b,,s#d ,na#b,,s#d #b;,h,cl4 7#b7 ,mn,o#b #d ,h,cl ,mn,cl#b #b;,cl #b;,h#b,o4 7#c7 ,mn,cl#b ,h#b,,s#d ,mn,s,o#d #b;,h,cl4 ,comb9+ ^! equations1 ! foll[+ equation express+ ! complete reaction is obta9$3 #b,na,cl ,mn,o#b #b;,h#b,,s#d ,mn,s,o#d ,na#b,,s#d #b;,h#b,o #b;,cl4 ,s9ce ! hydro*loric acid lib]at$ 9 ! ?ird equation is free to act ^u manganese dioxide1 x w be se5 t all ( ! *lor9e orig9ally pres5t 9 ! sodium *loride is set free4 ,! manganese dioxide & ! hydro*loric acid are br\ght toge!r 9 a flask1 z repres5t$ 9 ,fig4 #ec1 & a g5tle heat is appli$4 ,! rate ( evolution ( ! gas is regulat$ by ! am\nt ( heat appli$1 & ! gas is collect$ by displacem5t ( air4 ,z ! equations %[1 only half ( ! *lor9e pres5t 9 ! hydro*loric acid is lib]at$4 ,illu/ration3 ,fig4 #ec #b4 ,electrolytic me?od4 ,"u ! discussion ( electrolysis 7p4 #ajb7 x 0 %[n t :5 a solution ( sodium *loride is electrolyz$ *lor9e is evolv$ at ! anode1 :ile ! sodium set free at ! ca?ode reacts ) ! wat] to =m hydrog51 :i* is evolv$1 & sodium hydroxide1 :i* rema9s 9 solution4 ,a great deal ( ! *lor9e requir$ 9 ! *emical indu/ries is n[ made 9 ?is way 9 connection ) ! manufacture ( sodium hydroxide4 ,physical prop]ties4 ,*lor9e is a gre5i%-yell[ gas1 :i* has a peculi> suffocat+ odor & produces a v viol5t effect ^u ! ?roat & lungs4 ,ev5 :5 inhal$ 9 small quantities x (t5 produces all ! symptoms ( a h>d cold1 & 9 l>g] quantities may h s]i\s & ev5 fatal action4 ,x is q heavy 7d5sity #b4de7 & c !re=e be collect$ by displacem5t ( air4 ,"o volume ( wat] "u ord9>y conditions dissolves ab\t ?ree volumes ( *lor9e4 ,! gas is readily liquefi$1 a pressure ( six atmosph]es s]v+ to liquefy x at #j4 ,x =ms a yell[i% liquid :i* solidifies at -#ajb4 ,*emical prop]ties4 ,at ord9>y temp]atures *lor9e is f> m active *emically ?an any ( ! elem5ts we h s f> consid]$1 ) ! exception ( fluor9e2 inde$1 x is "o ( ! mo/ active ( all elem5ts4 #a4 ,action on metals4 ,a great _m metals comb9e directly ) *lor9e1 especially :5 hot4 ,a /rip ( copp] foil heat$ 9 a burn] flame & !n dropp$ into *lor9e burns ) inc&esc5ce4 ,sodium burns brilliantly :5 heat$ /rongly 9 slightly moi/ *lor9e4 ,gold & silv] are quickly t>ni%$ by ! gas4 #b4 ,action on non-metals4 ,*lor9e has likewise a /rong aff9ity = _m ( ! non-metals4 ,?us phosphorus burns 9 a curr5t ( ! gas1 :ile antimony & ars5ic 9 ! =m ( a f9e p[d] at once bur/ into flame :5 dropp$ into j>s ( ! gas4 ,! products =m$ 9 all cases :]e *lor9e comb9es ) ano!r elem5t are call$ *lorides4 #c4 ,action on hydrog54 ,*lor9e has a /rong aff9ity = hydrog51 unit+ ) x to =m hydro*loric acid4 ,a jet ( hydrog5 burn+ 9 ! air cont9ues to burn :5 introduc$ into a j> ( *lor9e1 giv+ a some:at lum9\s flame4 ,a mixture ( ! two gases explodes viol5tly :5 a sp>k is pass$ ?r\gh x or :5 x is expos$ to bright sunlight4 ,9 ! latt] case x is ! light & n ! heat :i* />ts ! action4 #d4 ,action on sub/ances conta9+ hydrog54 ,n only w *lor9e comb9e directly ) free hydrog5 b x w (t5 ab/ract ! elem5t f its comp\nds4 ,?us1 :5 *lor9e is pass$ into a solution conta9+ hydrosulphuric acid1 sulphur is precipitat$ & ,hydro*loric acid =m$4 ,! reaction is %[n by ! foll[+ equation3 ,h#b,s #b;,cl #b;,h,cl ,s4 ,) ammonia ! action is simil>3 ,,nh#c #c;,cl #c;,h,cl ,n4 ,! same t5d5cy is v /rik+ly se5 9 ! action ( *lor9e ^u turp5t9e4 ,! latt] sub/ance is l>gely made up ( comp\nds hav+ ! composition repres5t$ by ! =mula ,c#aj;,h#af4 ,:5 a /rip ( pap] moi/5$ ) w>m turp5t9e is plac$ 9 a j> ( *lor9e d5se fumes ( hydro*loric acid appe> & a black deposit ( c>bon is =m$4 ,ev5 wat]1 :i* is a v /able comp\nd1 c be decompos$ by *lor9e1 ! oxyg5 be+ lib]at$4 ,?is may be %[n 9 ! foll[+ way3 ,illu/ration3 ,fig4 #ed ,if a long tube ( r l>ge diamet] is fill$ ) a /rong solution ( *lor9e 9 wat] & inv]t$ 9 a vessel ( ! same solution1 z %[n 9 ,fig4 #ed1 & ! app>atus is plac$ 9 bright sunlight1 v soon bubbles ( a gas w be obs]v$ to rise ?r\gh ! solution & collect 9 ! tube4 ,an exam9ation ( ?is gas w %[ t x is oxyg54 ,x is lib]at$ f wat] 9 accordance ) ! foll[+ equation3 ,h#b,o #b;,cl #b;,h,cl ,o4 #e4 ,action on color sub/ances1--blea*+ action4 ,if /rips ( brightly color$ clo? or "s highly color$ fl[]s are plac$ 9 q dry *lor9e1 no m>k$ *ange 9 color is notic$ z a rule4 ,if1 h[ev]1 ! clo? & fl[]s are fir/ moi/5$1 ! color rapidly disappe>s1 t is1 ! objects are blea*$4 ,evid5tly ! moi/ure z well z ! *lor9e is conc]n$ 9 ! action1 & a /udy ( ! case %[s t ! *lor9e has comb9$ ) ! hydrog5 ( ! wat]4 ,! oxyg5 set free oxidizes ! color sub/ance1 conv]t+ x into a colorless comp\nd4 ,x is evid5t f ?is explanation t *lor9e w only blea* ^? sub/ances :i* are *ang$ into colorless comp\nds by oxidation4 #f4 ,action z a dis9fectant4 ,*lor9e has also m>k$ g]micidal prop]ties1 & ! free elem5t1 z well z comp\nds f :i* x is easily lib]at$1 are us$ z dis9fectants4 ,nasc5t /ate4 ,x w be notic$ t oxyg5 :5 set free f wat] by *lor9e is able to d :at ord9>y oxyg5 _c d1 = bo? ! clo? & ! fl[]s are un*ang$ 9 ! air :i* conta9s oxyg54 ,x is g5]ally true t ! activity ( an elem5t is greate/ at ! in/ant ( lib]ation f its comp\nds4 ,to express ?is fact elem5ts at ! in/ant ( lib]ation are said to be 9 ! nasc5t /ate4 ,x is nasc5t oxyg5 :i* does ! blea*+4 ,hydro*loric acid 7muriatic acid7 7,h,cl74 ,! prep>ation ( hydro*loric acid may be discuss$ "u two g5]al heads3 #a4 ,laboratory prep>ation4 ,! product =m$ by ! burn+ ( hydrog5 9 *lor9e is ! gas hydro*loric acid4 ,?is sub/ance is mu* m easily obta9$1 h[ev]1 by treat+ common salt 7sodium *loride7 ) sulphuric acid4 ,! foll[+ equation %[s ! reaction3 #b,na,cl ,h#b,,s#d ,na#b,,s#d #b;,h,cl4 ,! dry salt is plac$ 9 a flask furni%$ ) a funnel tube & an exit tube1 ! sulphuric acid is add$1 & ! flask g5tly w>m$4 ,! hydro*loric acid gas is rapidly giv5 (f & c be collect$ by displacem5t ( air4 ,! same app>atus c be us$ z 0 employ$ 9 ! prep>ation ( *lor9e 7,fig4 #ec74 ,:5 a solution ( salt is treat$ ) sulphuric acid !re is no v m>k$ action4 ,! hydro*loric acid =m$ is v soluble 9 wat]1 & s does n escape f ! solution2 h5ce a /ate ( equilibrium is soon rea*$ betwe5 ! f\r sub/ances repres5t$ 9 ! equation4 ,:5 conc5trat$ sulphuric acid1 9 :i* hydro*loric acid is n soluble1 is p\r$ ^u dry salt ! reaction is complete4 #b4 ,comm]cial prep>ation4 ,comm]cially1 hydro*loric acid is prep>$ 9 connection ) ! manufacture ( sodium sulphate1 ! reaction be+ ! same z t j giv54 ,! reaction is c>ri$ out 9 a furnace1 & ! hydro*loric acid z x escapes 9 ! =m ( gas is pass$ into wat] 9 :i* x dissolves1 ! solution =m+ ! hydro*loric acid ( comm]ce4 ,:5 ! mat]ials are pure a colorless solution is obta9$4 ,! mo/ conc5trat$ solution has a d5sity ( #a4b & conta9s #dj ,h,cl4 ,! comm]cial acid1 (t5 call$ muriatic acid1 is usually color$ yell[ by impurities4 ,composition ( hydro*loric acid4 ,:5 a solution ( hydro*loric acid is electrolyz$ 9 an app>atus simil> to ! "o 9 :i* wat] 0 electrolyz$ 7,fig4 #ah71 *lor9e collects at ! anode & hydrog5 at ! ca?ode4 ,at fir/ ! *lor9e dissolves 9 ! wat]1 b soon ! wat] 9 ! "o tube becomes saturat$ ) x1 & if ! /opcocks are left op5 until ?is is ! case1 & are !n clos$1 x w be se5 t ! two gases are set free 9 equal volumes4 ,:5 measur$ volumes ( ! two gases are caus$ to unite x is f\nd t "o volume ( hydrog5 comb9es ) "o ( *lor9e4 ,o!r exp]im5ts %[ t ! volume ( hydro*loric acid =m$ is j equal to ! sum ( ! volumes ( hydrog5 & *lor9e4 ,!re=e "o volume ( hydrog5 comb9es ) "o volume ( *lor9e to =m two volumes ( hydro*loric acid gas4 ,s9ce *lor9e is #ce4ah times z heavy z hydrog51 x foll[s t "o "p ( hydrog5 by weight comb9es ) #ce4ah p>ts ( *lor9e to =m #cf4ah p>ts ( hydro*loric acid4 ,physical prop]ties4 ,hydro*loric acid is a colorless gas :i* has an irritat+ effect :5 inhal$1 & possesses a s\r1 bit+ ta/e1 b no m>k$ odor4 ,x is heavi] ?an air 7d5sity #a4bf7 & is v soluble 9 wat]4 ,"u /&>d conditions #a volume ( wat] dissolves ab\t #ejj volumes ( ! gas4 ,on w>m+ su* a solution ! gas escapes1 until at ! boil+ po9t ! solution conta9s ab\t #bj by weight ( ,h,cl4 ,fur!r boil+ w n drive out any m acid1 b ! solution w di/ill ) un*ang$ conc5tration4 ,a m dilute solution ?an ?is w lose wat] on boil+ until x has rea*$ ! same conc5tration1 #bj1 & w !n di/ill un*ang$4 ,"u high pressure ! gas c be liquefi$1 #bh atmosph]es be+ requir$ at #j4 ,"u ^! conditions x =ms a colorless liquid :i* is n v active *emically4 ,x boils at -#hj & solidifies at -#aac4 ,! solution ( ! gas 9 wat] is us$ almo/ entirely 9 ! place ( ! gas itself1 s9ce x is n only f> m conv5i5t b also m active4 ,*emical prop]ties4 ,! mo/ important *emical prop]ties ( hydro*loric acid are ! foll[+3 #a4 ,action z an acid4 ,9 aque\s solution hydro*loric acid has v /rong acid prop]ties2 inde$1 x is "o ( ! /ronge/ acids4 ,x acts ^u oxides & hydroxides1 conv]t+ !m into salts3 ,na,o,h ,h,cl ,na,cl ,h#b,o1 ,cu,o #b;,h,cl ,cu,cl#b ,h#b,o4 ,x acts ^u _m metals1 =m+ *lorides & lib]at+ hydrog53 ,zn #b;,h,cl ,zn,cl#b #b;,h1 ,al #c;,h,cl ,al,cl#c #c;,h4 ,unlike nitric & sulphuric acids x has no oxidiz+ action1 s t :5 x acts on metals hydrog5 is always giv5 (f4 #b4 ,relation to combu/ion4 ,hydro*loric acid gas is n readily decompos$1 & is !re=e nei!r combu/ible nor a support] ( combu/ion4 #c4 ,action on oxidiz+ ag5ts4 ,al?\gh hydro*loric acid is incombu/ible1 x c be oxidiz$ "u "s circum/ances1 9 :i* case ! hydrog5 comb9es ) oxyg51 :ile ! *lor9e is set free4 ,?us1 :5 a solution ( hydro*loric acid acts ^u manganese dioxide "p ( ! *lor9e is set free3 ,mn,o#b #d;,h,cl ,mn,cl#b #b;,h#b,o #b;,cl4 ,aqua regia4 ,x has be5 se5 t :5 nitric acid acts z an oxidiz+ ag5t x usually decomposes1 z repres5t$ 9 ! equation #b;,,hno#c ,h#b,o #b,,no #c,o4 ,! oxyg5 s set free may act on hydro*loric acid3 #f;,h,cl #c,o #c;,h#b,o #f;,cl4 ,! complete equation !re=e is #b;,,hno#c #f;,h,cl #d;,h#b,o #b,,no #f;,cl4 ,:5 conc5trat$ nitric & hydro*loric acids are mix$ ?is reaction goes on sl[ly1 *lor9e & "s o!r sub/ances n repres5t$ 9 ! equation be+ =m$4 ,! mixture is kn[n z aqua regia & is commonly prep>$ by add+ "o volume ( nitric acid to ?ree volumes ( hydro*loric acid4 ,x acts m p[]fully ^u metals & o!r sub/ances ?an ei!r ( ! acids sep>ately1 & owes its /r5g? n to acid prop]ties b to ! action ( ! nasc5t *lor9e :i* x lib]ates4 ,consequ5tly1 :5 x acts ^u metals su* z gold x conv]ts !m into *lorides1 & ! reaction c be repres5t$ by su* equations z ,au #c;,cl ,au,cl#c4 ,salts ( hydro*loric acid1--*lorides4 ,! *lorides ( all ! metals are kn[n & _m ( !m are v important comp\nds4 ,"s ( !m are f\nd 9 nature1 & all c be prep>$ by ! g5]al me?od ( prep>+ salts4 ,silv] *loride1 lead *loride1 & m]cur\s *loride are insoluble 9 wat] & acids1 & c be prep>$ by add+ hydro*loric acid to solutions ( comp\nds ( ! respective elem5ts4 ,:ile ! *lorides h =mulas simil> to ! fluorides1 _! prop]ties are (t5 q diff]5t4 ,?is is se5 9 ! solubility ( ! salts4 ,^? metals ^: *lorides are insoluble =m soluble fluorides1 :ile _m ( ! metals :i* =m soluble *lorides =m insoluble fluorides4 ,comp\nds ( *lor9e ) oxyg5 & hydrog54 ,*lor9e comb9es ) oxyg5 & hydrog5 to =m f\r diff]5t acids4 ,!y are all q un/able1 & mo/ ( !m _c be prep>$ 9 pure =m2 _! salts c easily be made1 h[ev]1 & "s ( !m w be met ) 9 ! /udy ( ! metals4 ,! =mulas & names ( ^! acids are z foll[s3 ,h,cl,o hypo*lor\s acid4 ,h,cl,o#b *lor\s acid4 ,h,cl,o#c *loric acid4 ,h,cl,o#d p]*loric acid4 ,oxides ( *lor9e4 ,two oxides are kn[n1 hav+ ! =mulas ,cl#b,o & ,cl,o#b4 ,!y decompose v easily & are good oxidiz+ ag5ts4 ,,brom9e ,hi/orical4 ,brom9e 0 discov]$ 9 #ahbf by ! ,fr5* *emi/ ,ball>d1 :o isolat$ x f sea salt4 ,he nam$ x brom9e 7/5*7 because ( its unbe>able fumes4 ,occurr5ce4 ,brom9e occurs almo/ entirely 9 ! =m ( bromides1 especially z sodium bromide & magnesium bromide1 :i* are f\nd 9 _m salt spr+s & salt deposits4 ,! ,/assfurt deposits 9 ,g]many & ! salt wat]s ( ,ohio & ,mi*igan are especially ri* 9 bromides4 ,prep>ation ( brom9e4 ,! laboratory me?od ( prep>+ brom9e is ess5tially diff]5t f ! comm]cial me?od4 ,illu/ration ,fig4 #ee #a4 ,laboratory me?od4 ,z 9 ! case ( *lor9e1 brom9e c be prep>$ by ! action ( hydrobromic acid 7,h,br7 on manganese dioxide4 ,s9ce hydrobromic acid is n an article ( comm]ce1 a mixture ( sulphuric acid & a bromide is commonly sub/itut$ = x4 ,! mat]ials are plac$ 9 a retort arrang$ z %[n 9 ,fig4 #ee4 ,! end ( ! retort j t\*es ! surface ( ! wat] 9 ! te/ tube4 ,on heat+1 ! brom9e di/ills ov] & is collect$ 9 ! cold receiv]4 ,! equation is #b,na,br #b;,h#b,,s#d ,mn,o#b ,na#b,,s#d ,mn,s,o#d #b;,h#b,o #b;,br4 #b4 ,comm]cial me?od4 ,brom9e is prep>$ comm]cially f ! wat]s ( salt wells :i* are especially ri* 9 bromides4 ,on pass+ a curr5t ( electricity ?r\gh su* wat]s ! brom9e is fir/ lib]at$4 ,any *lor9e lib]at$1 h[ev]1 w assi/ 9 ! reaction1 s9ce free *lor9e decomposes bromides1 z %[n 9 ! equation ,na,br ,cl ,na,cl ,br4 ,:5 ! wat] conta9+ ! brom9e is heat$1 ! lib]at$ brom9e di/ills ov] into ! receiv]4 ,physical prop]ties4 ,brom9e is a d>k r$ liquid ab\t ?ree times z heavy z wat]4 ,its vapor has a v (f5sive odor & is mo/ irritat+ to ! eyes & ?roat4 ,! liquid boils at #ei & solidifies at -#g2 b ev5 at ord9>y temp]atures x evaporates rapidly1 =m+ a r$di%-br[n gas v simil> to nitrog5 p]oxide 9 appe>ance4 ,brom9e is some:at soluble 9 wat]1 #ajj volumes ( wat] "u ord9>y conditions dissolv+ #a volume ( ! liquid4 ,x is readily soluble 9 c>bon disulphide1 =m+ a yell[ solution4 ,*emical prop]ties & uses4 ,9 *emical action brom9e is v simil> to *lor9e4 ,x comb9es directly ) _m ( ! same elem5ts ) :i* *lor9e unites1 b ) less en]gy4 ,x comb9es ) hydrog5 & takes away ! latt] elem5t f "s ( its comp\nds1 b n s readily z does *lor9e4 ,its blea*+ prop]ties are also less m>k$4 ,brom9e f9ds _m uses 9 ! manufacture ( organic drugs & dye/uffs & 9 ! prep>ation ( bromides4 ,hydrobromic acid 7,h,br74 ,:5 sulphuric acid acts ^u a bromide hydrobromic acid is set free3 #b,na,br ,h#b,,s#d ,na#b,,s#d #b;,h,br4 ,at ! same "t "s brom9e is set free1 z may be se5 f ! r$ fumes :i* appe>1 & f ! odor4 ,! explanation ( ?is is f\nd 9 ! fact t hydrobromic acid is mu* less /able ?an hydro*loric acid1 & is !re=e m easily oxidiz$4 ,conc5trat$ sulphuric acid is a good oxidiz+ ag5t1 & oxidizes a "p ( ! hydrobromic acid1 lib]at+ brom9e3 ,h#b,,s#d #b;,h,br #b;,h#b,o ,,s#b #b;,br4 ,prep>ation ( pure hydrobromic acid4 ,a conv5i5t way to make pure hydrobromic acid is by ! action ( brom9e ^u moi/ r$ phosphorus4 ,?is c be done ) ! app>atus %[n 9 ,fig4 #ef4 ,brom9e is put into ! dropp+ funnel ,a1 & r$ phosphorus1 toge!r ) en\gh wat] to cov] x1 is plac$ 9 ! flask ,b4 ,by means ( ! /opcock ! brom9e is all[$ to fl[ drop by drop into ! flask1 ! reaction tak+ place )\t ! application ( heat4 ,! equations are 7#a7 ,p #c;,br ,p,br#c1 7#b7 ,p,br#c #c;,h#b,o ,p7,,oh7#c #c;,h,br4 ,illu/ration ,fig4 #ef ,! ,u-tube ,c conta9s glass beads :i* h be5 moi/5$ ) wat] & rubb$ 9 r$ phosphorus4 ,any brom9e escap+ action 9 ! flask acts ^u ! phosphorus 9 ! ,u-tube4 ,! hydrobromic acid is collect$ 9 ! same way z hydro*loric acid4 ,prop]ties4 ,hydrobromic acid v /rik+ly resembles hydro*loric acid 9 physical & *emical prop]ties4 ,x is a colorless1 /rongly fum+ gas1 heavi] ?an hydro*loric acid &1 l x1 is v soluble 9 wat]4 ,"u /&>d conditions #a volume ( wat] dissolves #faj volumes ( ! gas4 ,*emically1 ! *ief po9t 9 :i* x diff]s f hydro*loric acid is 9 ! fact t x is mu* m easily oxidiz$1 s t brom9e is m readily set free f x ?an *lor9e is f hydro*loric acid4 ,salts ( hydrobromic acid1--bromides4 ,! bromides are v simil> to ! *lorides 9 _! prop]ties4 ,*lor9e acts ^u bo? bromides & free hydrobromic acid1 lib]at+ brom9e f !m3 ,k,br ,cl ,k,cl ,br1 ,h,br ,cl ,h,cl ,br4 ,silv] bromide is ext5sively us$ 9 photography1 & ! bromides ( sodium & potassium are us$ z drugs4 ,oxyg5 comp\nds4 ,no oxides ( brom9e are surely kn[n1 & brom9e does n =m s _m oxyg5 acids z *lor9e does4 ,salts ( hypobrom\s acid 7,h,br,o7 & bromic acid 7,h,br,o#c7 are kn[n4 ,,iod9e ,hi/orical4 ,iod9e 0 discov]$ 9 #ahab by ,c\rtois 9 ! a%es ( c]ta9 sea plants4 ,its pres5ce 0 reveal$ by its beautiful violet vapor1 & ?is sugge/$ ! "n iod9e 7f ! ,greek = violet appe>ance74 ,occurr5ce4 ,9 ! comb9$ /ate iod9e occurs 9 v small quantities 9 sea wat]1 f :i* x is absorb$ by c]ta9 sea plants1 s t x is f\nd 9 _! a%es4 ,x occurs along ) brom9e 9 salt spr+s & b$s1 & is also f\nd 9 ,*ili saltpet]4 ,prep>ation4 ,iod9e may be prep>$ 9 a numb] ( ways1 ! pr9cipal me?ods be+ ! foll[+3 #a4 ,laboratory me?od4 ,iod9e c readily be prep>$ 9 ! laboratory f an iodide by ! me?od us$ 9 prep>+ brom9e1 except t sodium iodide is sub/itut$ = sodium bromide4 ,x c also be made by pass+ *lor9e into a solution ( an iodide4 ,illu/ration3 ,fig4 #eg #b4 ,comm]cial me?od4 ,comm]cially iod9e 0 =m]ly prep>$ f seawe$ 7kelp71 b is n[ obta9$ almo/ entirely f ! deposits ( ,*ili saltpet]4 ,! crude saltpet] is dissolv$ 9 wat] & ! solution evaporat$ until ! saltpet] cry/allizes4 ,! rema9+ liquors1 kn[n z ! "m liquors1 conta9 sodium iodate 7,na,i,o#c71 9 :i* =m ! iod9e is pres5t 9 ! saltpet]4 ,! *emical reaction by :i* ! iod9e is lib]at$ f ?is comp\nd is a complicat$ "o1 dep5d+ on ! fact t sulphur\s acid acts ^u iodic acid1 sett+ iod9e free4 ,?is reaction is %[n z foll[s3 #b;,,hio#c #e;,h#b,,s#c #e;,h#b,,s#d ,h#b,o #b;,i4 ,purification ( iod9e4 ,iod9e c be purifi$ v conv5i5tly 9 ! foll[+ way4 ,! crude iod9e is plac$ 9 an evaporat+ di% ,e 7,fig4 #eg71 & ! di% is set ^u ! s& ba? ,s4 ,! iod9e is cov]$ ) ! inv]t$ funnel ,f1 & ! s& ba? is g5tly heat$ ) a ,buns5 burn]4 ,z ! di% becomes w>m ! iod9e rapidly evaporates & cond5ses aga9 on ! cold surface ( ! funnel 9 %9+ cry/als4 ,?is process1 9 :i* a solid is conv]t$ into a vapor & is aga9 cond5s$ into a solid )\t pass+ ?r\gh ! liquid /ate1 is call$ sublimation4 ,physical prop]ties4 ,iod9e is a purpli%-black1 %9+1 heavy solid :i* cry/allizes 9 brilliant plates4 ,ev5 at ord9>y temp]atures x gives (f a beautiful violet vapor1 :i* increases 9 am\nt z heat is appli$4 ,x melts at #ajg & boils at #age4 ,x is slightly soluble 9 wat]1 b readily dissolves 9 alcohol1 =m+ a br[n solution 7t9cture ( iod9e71 & 9 c>bon disulphide1 =m+ a violet solution4 ,! elem5t has a /rong1 unpleasant odor1 ?\gh by no means z irritat+ z t ( *lor9e & brom9e4 ,*emical prop]ties4 ,*emically iod9e is q simil> to *lor9e & brom9e1 b is /ill less active ?an brom9e4 ,x comb9es directly ) _m elem5ts at ord9>y temp]atures4 ,at elevat$ temp]atures x comb9es ) hydrog51 b ! reaction is rev]sible & ! comp\nd =m$ is q easily decompos$4 ,bo? *lor9e & brom9e displace x f its salts3 ,,ki ,br ,k,br ,i1 ,,ki ,cl ,k,cl ,i4 ,:5 ev5 m9ute traces ( iod9e are add$ to ?9 />* pa/e a v int5se blue color develops1 & ?is reaction =ms a delicate te/ = iod9e4 ,iod9e is ext5sively us$ 9 m$ic9e1 especially 9 ! =m ( a t9cture4 ,x is also l>gely us$ 9 ! prep>ation ( dyes & organic drugs1 iod(orm1 a sub/ance us$ z an antiseptic1 has ! =mula ,,*i#c4 ,hydriodic acid 7,,hi74 ,?is acid _c be prep>$ 9 pure condition by ! action ( sulphuric acid ^u an iodide1 s9ce ! hydriodic acid set free is oxidiz$ by ! sulphuric acid j z 9 ! case ( hydrobromic acid1 b to a mu* great] ext5t4 ,x c be prep>$ 9 exactly ! same way z hydrobromic acid1 iod9e be+ sub/itut$ = brom9e4 ,x c also be prep>$ by pass+ hydrosulphuric acid into wat] 9 :i* iod9e is susp5d$4 ,! equation is ,h#b,s #b;,i #b;,,hi ,s4 ,! hydriodic acid =m$ 9 ?is way dissolves 9 ! wat]4 ,prop]ties & uses4 ,hydriodic acid resembles ! correspond+ acids ( *lor9e & brom9e 9 physical prop]ties1 be+ a /rongly fum+1 colorless gas1 readily soluble 9 wat]4 ,"u /&>d conditions #a volume ( wat] dissolves ab\t #dfj volumes ( ! gas4 ,x is1 h[ev]1 m un/able ?an ei!r hydro*loric or hydrobromic acids1 & on exposure to ! air x gradually decomposes 9 accordance ) ! equation #b;,,hi ,o ,h#b,o #b;,i4 ,ow+ to ! slight aff9ity betwe5 iod9e & hydrog5 ! acid easily gives up its hydrog5 & is !re=e a /rong r$uc+ ag5t4 ,?is is se5 9 its action on sulphuric acid4 ,! salts ( hydriodic acid1 ! iodides1 are1 9 g5]al1 simil> to ! *lorides & bromides4 ,potassium iodide 7,,ki7 is ! mo/ famili> ( ! iodides & is l>gely us$ 9 m$ic9e4 ,oxyg5 comp\nds4 ,iod9e has a mu* great] aff9ity = oxyg5 ?an has ei!r *lor9e or brom9e4 ,:5 heat$ ) nitric acid x =ms a /able oxide 7,i#b,o#e74 ,salts ( iodic acid 7,,hio#c7 & p]iodic acid 7,,hio#d7 are easily prep>$1 & ! free acids are mu* m /able ?an ! correspond+ acids ( ! o!r memb]s ( ?is family4 ,,gay-,,lussac',s ,,law ,,( ,,volumes ,9 ! discussion ( ! composition ( hydro*loric acid x 0 /at$ t "o volume ( hydrog5 comb9es ) "o volume ( *lor9e to =m two volumes ( hydro*loric acid4 ,) brom9e & iod9e simil> comb9+ ratios hold good4 ,^! facts recall ! simple volume relations already not$ 9 ! /udy ( ! composition ( /eam & ammonia4 ,^! relations may be repres5t$ graphically 9 ! foll[+ way3 --- ---- ------ ------ ,h ,cl ,h ,cl ,h ,cl --- ---- ------ ------ --- --- --- -------- -------- ,h ,h ,o ,h#b,o ,h#b,o --- --- --- -------- -------- --- --- --- --- -------- -------- ,h ,h ,h ,n ,,nh#c ,,nh#c --- --- --- --- -------- -------- ,9 ! e>ly "p ( ! pa/ c5tury ,gay-,lussac1 a di/+ui%$ ,fr5* *emi/1 /udi$ ! volume relations ( _m comb9+ gases1 & conclud$ t simil> relations always hold4 ,8 obs]vations are summ$ up 9 ! foll[+ law3 ,:5 two gases comb9e *emically !re is always a simple ratio betwe5 _! volumes1 & betwe5 ! volume ( ei!r "o ( !m & t ( ! product1 provid$ x is a gas4 ,by a simple ratio is meant ( c\rse ! ratio ( small :ole numb]s1 z #a 3 #b1 #b 3 #c4 ,,ex]cises #a4 ,h[ d we acc\nt = ! fact t liquid hydr(luoric acid is n an electrolyte8 #b4 ,:y does sulphuric acid lib]ate hydr(luoric acid f its salts8 #c4 ,9 ! prep>ation ( *lor9e1 :at advantages are !re 9 treat+ manganese dioxide ) a mixture ( sodium *loride & sulphuric acid r ?an ) hydro*loric acid8 #d4 ,:y mu/ *lor9e wat] be kept 9 ! d>k8 #e4 ,:at is ! d]ivation ( ! ^w nasc5t8 #f4 ,:at sub/ances /udi$ are us$ z blea*+ ag5ts8 ,to :at is ! blea*+ action due 9 ea* case8 #g4 ,:at sub/ances /udi$ are us$ z dis9fect+ ag5ts8 #h4 ,:at is meant by ! /atem5t t hydro*loric acid is "o ( ! /ronge/ acids8 #i4 ,:at is ! mean+ ( ! phrase aqua regia8 #aj4 ,cl#b,o is ! anhydride ( :at acid8 #aa4 ,a solution ( hydriodic acid on /&+ turns br[n4 ,h[ is ?is acc\nt$ =8 #ab4 ,h[ c brom9e vapor & nitrog5 p]oxide be di/+ui%$ f ea* o!r8 #ac4 ,write ! equations = ! reaction tak+ place :5 hydriodic acid is prep>$ f iod9e1 phosphorus1 & wat]4 #ad4 ,f _! behavior t[>d sulphuric acid1 to :at class ( ag5ts d hydrobromic & hydriodic acids belong8 #ae4 ,give ! d]ivation ( ! names ( ! elem5ts ( ! *lor9e family4 #af4 ,write ! names & =mulas = ! b9>y acids ( ! gr\p 9 ! ord] ( ! /ability ( ! acids4 #ag4 ,:at is =m$ :5 a metal dissolves 9 ea* ( ! foll[+8 nitric acid2 dilute sulphuric acid2 conc5trat$ sulphuric acid2 hydro*loric acid2 aqua regia4 #ah4 ,h[ c\ld y di/+ui% betwe5 a *loride1 a bromide1 & an iodide8 #ai4 ,:at weight ( sodium *loride is necess>y to prep>e suffici5t hydro*loric acid to saturate #a l4 ( wat] "u /&>d conditions8 #bj4 ,on decomposition #ajj l4 ( hydro*loric acid w\ld yield h[ _m lit]s ( hydrog5 & *lor9e respectively1 ! gases be+ measur$ "u ! same conditions8 ,are y\r results 9 accord ) ! exp]im5tal facts8 ,,*apt] ,,xvii ,,c>bon ,,& ,,"s ,,( ,,its ,,simpl] ,,comp\nds ,! family4 ,c>bon /&s at ! head ( a family ( elem5ts 9 ! f\r? gr\p 9 ! p]iodic table4 ,! resemblances betwe5 ! elem5ts ( ?is family1 :ile q m>k$1 are n s /rik+ z 9 ! case ( ! elem5ts ( ! *lor9e family4 ,) ! exception ( c>bon1 ^! elem5ts are comp>atively r>e1 & ne$ n be tak5 up 9 detail 9 ?is *apt]4 ,titanium w be ref]r$ to aga9 9 connection ) silicon :i* x v closely resembles4 ,occurr5ce4 ,c>bon is f\nd 9 nature 9 ! uncomb9$ /ate 9 sev]al =ms4 ,! diamond is practically pure c>bon1 :ile graphite & coal are l>gely c>bon1 b conta9 small am\nts ( o!r sub/ances4 ,its natural comp\nds are exce$+ly num]\s & occur z gases1 liquids1 & solids4 ,c>bon dioxide is its mo/ famili> gase\s comp\nd4 ,natural gas & petroleum are l>gely comp\nds ( c>bon ) hydrog54 ,! c>bonates1 especially calcium c>bonate1 con/itute great /rata ( rocks1 & are f\nd 9 almo/ e locality4 ,all liv+ organisms1 bo? plant & animal1 conta9 a l>ge p]c5tage ( ?is elem5t1 & ! numb] ( its comp\nds :i* g to make up all ! va/ v>iety ( animate nature is almo/ limitless4 ,ov] "o hundr$ ?\s& def9ite comp\nds conta9+ c>bon h be5 prep>$4 ,9 ! free /ate c>bon occurs 9 ?ree allotropic =ms1 two ( :i* are cry/all9e & "o amorph\s4 ,cry/all9e c>bon4 ,cry/all9e c>bon occurs 9 two =ms1--diamond & graphite4 #a4 ,diamond4 ,diamonds are f\nd 9 consid]able quantities 9 sev]al localities1 especially 9 ,s\? ,africa1 ! ,ea/ ,indies1 & ,brazil4 ,! cry/als belong to ! regul> sy/em1 b ! natural /ones d n %[ ?is v cle>ly4 ,:5 f\nd !y are usually cov]$ ) a r\gh coat+ :i* is remov$ 9 ! process ( cutt+4 ,diamond cutt+ is c>ri$ on mo/ ext5sively 9 ,holl&4 ,! d5sity ( ! diamond is #c4e1 &1 ?\gh brittle1 x is "o ( ! h>de/ ( sub/ances4 ,black diamonds1 z well z brok5 & imp]fect /ones :i* are valueless z gems1 are us$ = gr9d+ h>d sub/ances4 ,few *emical reag5ts h any action on ! diamond1 b :5 heat$ 9 oxyg5 or ! air x black5s & burns1 =m+ c>bon dioxide4 ,lavoisi] fir/ %[$ t c>bon dioxide is =m$ by ! combu/ion ( ! diamond2 & ,sir ,humphry ,davy 9 #ahad %[$ t ?is is ! only product ( combu/ion1 & t ! diamond is pure c>bon4 ,! diamond z a gem4 ,! pure diamond is p]fectly transp>5t & colorless1 b _m are t9t$ a v>iety ( colors by traces ( =eign sub/ances4 ,usually ! colorless ones are ! mo/ highly priz$1 al?\gh 9 "s in/ances ! color adds to ! value2 ?us ! fam\s ,hope diamond is a beautiful blue4 ,light pass+ ?r\gh a diamond is v mu* refract$1 & to ?is fact ! /one owes its brilliancy & sp>kle4 ,artificial prep>ation ( diamonds4 ,_m attempts h be5 made to produce diamonds artificially1 b = a long "t ^! always end$ 9 failure1 graphite & n diamonds be+ ! product obta9$4 ,! ,fr5* *emi/ ,moissan1 9 8 ext5d$ /udy ( *emi/ry at high temp]atures1 f9ally succe$$ 7#ahic7 9 mak+ "s small ones4 ,he accompli%$ ?is by dissolv+ c>bon 9 boil+ iron & plung+ ! crucible conta9+ ! mixture into wat]1 z %[n 9 ,fig4 #eh4 ,"u ^! conditions ! c>bon cry/alliz$ 9 ! iron 9 ! =m ( ! diamond4 ,! diamonds 7 !n obta9$ by dissolv+ away ! iron 9 hydro*loric acid4 ,illu/ration3 ,fig4 #eh #b4 ,graphite4 ,?is =m ( c>bon is f\nd 9 l>ge quantities1 especially 9 ,ceylon1 ,sib]ia1 & 9 "s localities ( ! ,unit$ ,/ates & ,canada4 ,x is a %9+ black sub/ance1 v s(t & greasy to ! t\*4 ,its d5sity is ab\t #b4ae4 ,x v>ies some:at 9 prop]ties accord+ to ! locality 9 :i* x is f\nd1 & is m easily attack$ by reag5ts ?an is ! diamond4 ,x is also manufactur$ by heat+ c>bon ) a small am\nt ( iron 7#c7 9 an electric furnace4 ,x is us$ 9 ! manufacture ( lead p5cils & crucibles1 z a lubricant1 & z a protective cov]+ = iron 9 ! =m ( a poli% or a pa9t4 ,amorph\s c>bon4 ,al?\gh !re are _m v>ieties ( amorph\s c>bon kn[n1 !y are n true allotropic modifications4 ,!y diff] m]ely 9 _! degree ( purity1 _! f95ess ( division1 & 9 _! mode ( prep>ation4 ,^! sub/ances are ( ! greate/ importance1 ow+ to _! _m uses 9 ! arts & indu/ries4 ,z !y occur 9 nature1 or are made artificially1 !y are ne>ly all impure c>bon1 ! impurity dep5d+ on ! p>ticul> sub/ance 9 "q4 #a4 ,pure c>bon4 ,pure amorph\s c>bon is be/ prep>$ by *>r+ sug>4 ,?is is a sub/ance consi/+ ( c>bon1 hydrog51 & oxyg51 ! latt] two elem5ts be+ pres5t 9 ! ratio ( "o oxyg5 atom to two ( hydrog54 ,:5 sug> is /rongly heat$ ! oxyg5 & hydrog5 are driv5 (f 9 ! =m ( wat] & pure c>bon is left beh9d4 ,prep>$ 9 ?is way x is a s(t1 lu/r\s1 v bulky1 black p[d]4 #b4 ,coal & coke4 ,coals ( v>i\s k9ds 7 probably =m$ f va/ accumulations ( vegetable matt] 9 =m] ages1 :i* became cov]$ ov] ) e>?y mat]ial & 7 ?us protect$ f rapid decay4 ,"u v>i\s natural ag5cies ! organic matt] 0 sl[ly *ang$ into coal4 ,9 an?racite ^! *anges h gone ! f>!/1 & ?is v>iety ( coal is ne>ly pure c>bon4 ,s(t or bitum9\s coals conta9 consid]able organic matt] besides c>bon & m9]al sub/ances4 ,:5 heat$ /rongly out ( contact ) air ! organic matt] is decompos$ & ! result+ volatile matt] is driv5 (f 9 ! =m ( gases & vapors1 & only ! m9]al matt] & c>bon rema9 beh9d4 ,! gase\s product is *iefly illum9at+ gas & ! solid residue is coke4 ,"s ( ! coke is f\nd z a d5se cake on ! sides & ro( ( ! retort4 ,?is is call$ retort c>bon & is q pure4 #c4 ,*>coal4 ,?is is prep>$ f wood 9 ! same way t coke is made f coal4 ,:5 ! process is c>ri$ on 9 retorts ! products expell$ by ! heat are sav$4 ,among ^! are _m valuable sub/ances su* z wood alcohol & acetic acid4 ,:]e timb] is abundant ! process is c>ri$ out 9 a wa/eful way1 by m]ely cov]+ piles ( wood ) sod & sett+ ! wood on fire4 ,"s wood burns & ! heat f ?is decomposes ! wood n burn$1 =m+ *>coal f x4 ,! *>coal1 ( c\rse1 conta9s ! m9]al "p ( ! wood f :i* x is =m$4 #d4 ,bone black4 ,?is is sometimes call$ animal *>coal1 & is made by *>r+ bones & animal refuse4 ,! organic "p ( ! mat]ials is ?us decompos$ & c>bon is left 9 a v f9ely divid$ /ate1 scatt]$ ?r\gh ! m9]al "p :i* consi/s l>gely ( calcium phosphate4 ,= "s uses ?is m9]al "p is remov$ by treatm5t ) hydro*loric acid & prolong$ wa%+4 #e4 ,lampblack4 ,lampblack & soot are products ( imp]fect combu/ion ( oil & coal1 & are deposit$ f a smoky flame on a cold surface4 ,! c>bon 9 ?is =m is v f9ely divid$ & usually conta9s v>i\s oily mat]ials4 ,prop]ties4 ,:ile ! v>i\s =ms ( c>bon diff] 9 _m prop]ties1 especially 9 color & h>dness1 yet !y are all odorless1 ta/eless solids1 insoluble 9 wat] & *>act]iz$ by _! /ability t[>ds heat4 ,only 9 ! int5se heat ( ! electric arc does c>bon volatilize1 pass+ directly f ! solid /ate into a vapor4 ,ow+ to ?is fact ! inside surface ( an inc&esc5t light bulb aft] be+ us$ = "s "t becomes coat$ ) a d>k film ( c>bon4 ,x is n act$ on at ord9>y temp]atures by mo/ reag5ts1 b at a high] temp]ature x comb9es directly ) _m ( ! elem5ts1 =m+ comp\nds call$ c>bides4 ,:5 heat$ 9 ! pres5ce ( suffici5t oxyg5 x burns1 =m+ c>bon dioxide4 ,uses ( c>bon4 ,! *ief use ( amorph\s c>bon is = fuel to furni% heat & p[] = all ! uses ( civilization4 ,an enorm\s quantity ( c>bon 9 ! =m ( ! pur] coals1 coke1 & *>coal is us$ z a r$uc+ ag5t 9 ! manufacture ( ! v>i\s metals1 especially 9 ! metallurgy ( iron4 ,mo/ ( ! metals are f\nd 9 nature z oxides1 or 9 =ms :i* c readily be conv]t$ into oxides4 ,:5 ^! oxides are heat$ ) c>bon ! oxyg5 is ab/ract$1 leav+ ! metal4 ,retort c>bon & coke are us$ to make electric light c>bons & batt]y plates1 :ile lampblack is us$ = indelible inks1 pr9t]'s ink1 & black v>ni%es4 ,bone black & *>coal h ! prop]ty ( absorb+ l>ge volumes ( c]ta9 gases1 z well z small] am\nts ( organic matt]2 h5ce !y are us$ 9 filt]s to remove noxi\s gases & objectionable colors & odors f wat]4 ,bone black is us$ ext5sively 9 ! sug> ref9]ies to remove color+ matt] f ! impure sug>s4 ,*emi/ry ( c>bon comp\nds4 ,c>bon is rem>kable = ! v l>ge numb] ( comp\nds :i* x =ms ) ! o!r elem5ts1 especially ) oxyg5 & hydrog54 ,comp\nds conta9+ c>bon are m num]\s ?an all o!rs put toge!r1 & ! *emi/ry ( ^! sub/ances pres5ts peculi>ities n met ) 9 ! /udy ( o!r sub/ances4 ,= ^! reasons ! sy/ematic /udy ( c>bon comp\nds1 or ( organic *emi/ry z x is usually call$1 mu/ be def]r$ until ! /ud5t has ga9$ "s k ( ! *emi/ry ( o!r elem5ts4 ,an acqua9tance ) a few ( ! mo/ famili> c>bon comp\nds is1 h[ev]1 ess5tial = ! und]/&+ ( ! g5]al pr9ciples ( *emi/ry4 ,comp\nds ( c>bon ) hydrog51--! hydroc>bons4 ,c>bon unites ) hydrog5 to =m a v l>ge numb] ( comp\nds call$ hydroc>bons4 ,petroleum & natural gas are ess5tially mixtures ( a great v>iety ( ^! hydroc>bons4 ,_m o!rs are f\nd 9 liv+ plants1 & /ill o!rs are produc$ by ! decay ( organic matt] 9 ! abs5ce ( air4 ,only two ( !m1 me?ane & acetyl5e1 w be discuss$ "h4 ,me?ane 7m>% gas7 7,,*#d74 ,?is is "o ( ! mo/ important ( ^! hydroc>bons1 & con/itutes ab\t n9e t5?s ( natural gas4 ,z its "n sugge/s1 x is =m$ 9 m>%es by ! decay ( vegetable matt] "u wat]1 & bubbles ( ! gas are (t5 se5 to rise :5 ! dead leaves on ! bottom ( pools are /irr$4 ,x also collects 9 m9es1 &1 :5 mix$ ) air1 is call$ fire damp by ! m9]s because ( its great inflammability1 damp be+ an old "n = a gas4 ,x is =m$ :5 organic matt]1 su* z coal or wood1 is heat$ 9 clos$ vessels1 & is !re=e a pr9cipal con/itu5t ( coal gas4 ,prep>ation4 ,me?ane is prep>$ 9 ! laboratory by heat+ sodium or calcium acetate ) soda-lime4 ,equal weights ( fus$ sodium acetate & soda-lime are ?or\ghly dri$1 !n mix$ & plac$ 9 a good-siz$1 h>d-glass te/ tube fitt$ ) a "o-hol$ /opp] & deliv]y tube4 ,! mixture is gradually heat$1 & :5 ! air has be5 displac$ f ! tube ! gas is collect$ 9 bottles by displacem5t ( wat]4 ,soda-lime is a mixture ( sodium & calcium hydroxides4 ,reg>d+ x z sodium hydroxide alone1 ! equation is ,na,c#b;,h#c,o#b ,na,o,h ,na#b;,,co#c ,,*#d4 ,prop]ties4 ,me?ane is a colorless1 odorless gas ^: d5sity is #j4ee4 ,x is difficult to liquefy1 boil+ at -#aee "u /&>d pressure1 & is almo/ insoluble 9 wat]4 ,x burns ) a pale blue flame1 lib]at+ mu* heat1 & :5 mix$ ) oxyg5 is v explosive4 ,davy's safety lamp4 ,9 #ahae ,sir ,humphry ,davy inv5t$ a lamp = ! use ( m9]s1 to prev5t ! dreadful m9e explosions !n common1 due to me?ane mix$ ) air4 ,! inv5tion consi/$ 9 surr\nd+ ! upp] "p ( ! common m9]'s lamp ) a mantle ( wire gauze & ! l[] "p ) glass 7,fig4 #ei74 ,x has be5 se5 t two gases w n comb9e until rais$ to _! k9dl+ temp]ature1 & if :ile comb9+ !y are cool$ bel[ ?is po9t1 ! comb9ation ceases4 ,a flame w n pass ?r\gh a wire gauze because ! metal1 be+ a good conductor ( heat1 takes away s mu* heat f ! flame t ! gases are cool$ bel[ ! k9dl+ temp]ature4 ,:5 a lamp s protect$ is br\ght into an explosive mixture ! gases inside ! wire mantle burn 9 a s]ies ( little explosions1 giv+ w>n+ to ! m9] t ! air is unsafe4 ,illu/ration3 ,fig4 #ei ,acetyl5e 7,c#b;,h#b74 ,?is is a colorless gas usually hav+ a disagreeable odor due to impurities4 ,x is n[ made 9 l>ge quantities f calcium c>bide 7,ca,c#b74 ,?is sub/ance is =m$ :5 coal & lime are heat$ toge!r 9 an electric furnace4 ,:5 treat$ ) wat] ! c>bide is decompos$1 yield+ acetyl5e3 ,ca,c#b #b;,h#b,o ,c#b;,h#b ,ca7,,oh7#b4 ,"u ord9>y conditions ! gas burns ) a v smoky flame2 9 burn]s con/ruct$ s z to secure a l>ge am\nt ( oxyg5 x burns ) a v brilliant :ite light1 & h5ce is us$ z an illum9ant4 ,laboratory prep>ation4 ,! gas c be prep>$ readily 9 a g5]ator su* z is %[n 9 ,fig4 #fj4 ,! inn] tube conta9s fragm5ts ( calcium c>bide1 :ile ! out] "o is fill$ ) wat]4 ,z long z ! /opcock is clos$ ! wat] _c rise 9 ! inn] tube4 ,:5 ! /opcock is op5 ! wat] rises1 &1 com+ into contact ) ! c>bide 9 ! inn] tube1 g5]ates acetyl5e4 ,?is escapes ?r\gh ! /opcock1 & aft] ! air has be5 expell$ may be light$ z x issues f ! burn]4 ,illu/ration3 ,fig4 #fj ,c>bon =ms two oxides1 namely1 c>bon dioxide 7,,co#b7 & c>bon monoxide 7,,co74 ,c>bon dioxide 7,,co#b74 ,c>bon dioxide is pres5t 9 ! air to ! ext5t ( ab\t #c p>ts 9 #aj1jjj1 & ?is app>5tly small am\nt is ( fundam5tal importance 9 nature4 ,9 "s localities x escapes f ! e>? 9 great quantities1 & _m spr+ wat]s c>ry l>ge am\nts ( x 9 solution4 ,:5 ^! highly *>g$ spr+ wat]s rea* ! surface ( ! e>?1 & ! pressure on !m is remov$1 ! c>bon dioxide escapes ) eff]vesc5ce4 ,x is a product ( ! oxidation ( all organic matt]1 & is !re=e =m$ 9 fires z well z 9 ! process ( decay4 ,x is ?r[n (f f ! lungs ( all animals 9 respiration1 & is a product ( _m f]m5tation processes su* z v9eg> mak+ & brew+4 ,comb9$ ) metallic oxides x =ms va/ deposits ( c>bonates 9 nature4 ,prep>ation4 ,9 ! laboratory c>bon dioxide is always prep>$ by ! action ( an acid ^u a c>bonate1 usually calcium c>bonate1 ! app>atus %[n 9 ,fig4 #ci s]v+ ! purpose v well4 ,?is reaction might be expect$ to produce c>bonic acid1 ?us3 ,ca,c,o#c #b;,h,cl ,ca,cl#b ,h#b;,,co#c4 ,c>bonic acid is v un/able1 h[ev]1 & decomposes into its anhydride1 ,,co#b1 & wat]1 ?us3 ,h#b;,,co#c ,h#b,o ,,co#b4 ,! complete reaction is repres5t$ by ! equation ,ca,c,o#c #b;,h,cl ,ca,cl#b ,,co#b ,h#b,o4 ,physical prop]ties4 ,c>bon dioxide is a colorless1 practically odorless gas ^: d5sity is #a4e4 ,its weight may be inf]r$ f ! fact t x c be siphon$1 or p\r$ l wat]1 f "o vessel d[nw>d into ano!r4 ,at #ae & "u ord9>y pressure x dissolves 9 its own volume ( wat] & imp>ts a some:at bit+1 pung5t ta/e to x4 ,x is easily cond5s$1 & is n[ prep>$ comm]cially 9 ?is =m by pump+ ! gas into /eel cyl9d]s 7see ,fig4 #f7 :i* are kept cold dur+ ! process4 ,:5 ! liquid is p]mitt$ to escape into ! air "p ( x in/antly evaporates1 & 9 s do+ absorbs s mu* heat t ano!r portion is solidifi$1 ! solid =m /rik+ly resembl+ sn[ 9 appe>ance4 ,?is sn[ is v cold & m]cury c easily be froz5 ) x4 ,solid c>bon dioxide4 ,cyl9d]s ( liquid c>bon dioxide are inexp5sive1 & %\ld be available 9 e s*ool4 ,to demon/rate ! prop]ties ( solid c>bon dioxide1 ! cyl9d] %\ld be plac$ across ! table & support$ 9 su* a way t ! /opcock end is sev]al in*es l[] ?an ! o!r end4 ,a loose bag is made by hold+ ! corn]s ( a h&k]*ief ar\nd ! neck ( ! /opcock1 & ! cock is !n turn$ on s t ! gas ru%es out 9 l>ge quantities4 ,v quickly a consid]able quantity ( ! sn[ collects 9 ! h&k]*ief4 ,to freeze m]cury1 press a piece ( filt] pap] into a small evaporat+ di% & p\r ! m]cury ^u x4 ,coil a flat spiral ^u ! end ( a wire1 & dip ! spiral into ! m]cury4 ,place a quantity ( solid c>bon dioxide ^u ! m]cury & p\r #aj cc4-#ae cc4 ( e!r ov] x4 ,9 a m9ute or two ! m]cury w solidify & may be remov$ f ! di% by ! wire s]v+ z a h&le4 ,! filt] pap] is to prev5t ! m]cury f /ick+ to ! di%2 ! e!r dissolves ! solid c>bon dioxide & promotes its rapid conv]sion into gas4 ,*emical prop]ties4 ,c>bon dioxide is incombu/ible1 s9ce x is1 l wat]1 a product ( combu/ion4 ,x does n support combu/ion1 z does nitrog5 p]oxide1 because ! oxyg5 9 x is held 9 v firm *emical union ) ! c>bon4 ,v /rong r$uc+ ag5ts1 su* z highly heat$ c>bon1 c take away half ( its oxyg53 ,,co#b ,c #b;,,co4 ,uses4 ,! relation ( c>bon dioxide to plant life has be5 discuss$ 9 a previ\s *apt]4 ,wat] highly *>g$ ) c>bon dioxide is us$ = mak+ soda wat] & simil> bev]ages4 ,s9ce x is a non-support] ( combu/ion & c be g5]at$ readily1 c>bon dioxide is also us$ z a fire ext+ui%]4 ,"s ( ! portable fire ext+ui%]s are simply devices = g5]at+ l>ge am\nts ( ! gas4 ,x is n necess>y t all ! oxyg5 %\ld be kept away f ! fire 9 ord] to smo!r x4 ,a burn+ c&le is ext+ui%$ 9 air :i* conta9s only #b4e ( c>bon dioxide4 ,c>bonic acid 7,h#b;,,co#c74 ,l mo/ ( ! oxides ( ! non-metallic elem5ts1 c>bon dioxide is an acid anhydride4 ,x comb9es ) wat] to =m an acid ( ! =mula ,h#b;,,co#c1 call$ c>bonic acid3 ,h#b,o ,,co#b ,h#b;,,co#c4 ,! acid is1 h[ev]1 v un/able & _c be isolat$4 ,only a v small am\nt ( x is actually =m$ :5 c>bon dioxide is pass$ into wat]1 z is evid5t f ! small solubility ( ! gas4 ,if1 h[ev]1 a base is pres5t 9 ! wat]1 salts ( c>bonic acid are =m$1 & ^! are q /able3 #b,na,o,h ,h#b,o ,,co#b ,na#b;,,co#c #b;,h#b,o4 ,action ( c>bon dioxide on bases4 ,?is conduct is expla9$ by ! pr9ciples ( rev]sible reactions4 ,! equation ,h#b,o ,,co#b -- ,h#b;,,co#c is a rev]sible equation1 & ! ext5t to :i* ! reaction progresses dep5ds ^u ! relative conc5trations ( ea* ( ! ?ree factors 9 x4 ,equilibrium is ord9>ily rea*$ :5 v little ,h#b;,,co#c is =m$4 ,if a base is pres5t 9 ! wat] to comb9e ) ! ,h#b;,,co#c z fa/ z x is =m$1 all ( ! ,,co#b is conv]t$ into ,h#b;,,co#c1 & !nce into a c>bonate4 ,salts ( c>bonic acid1--c>bonates4 ,! c>bonates =m a v important class ( salts4 ,!y are f\nd 9 l>ge quantities 9 nature1 & are (t5 us$ 9 *emical processes4 ,only ! c>bonates ( sodium1 potassium1 & ammonium are soluble1 & ^! c be made by ! action ( c>bon dioxide on solutions ( ! bases1 z has j be5 expla9$4 ,! insoluble c>bonates are =m$ z precipitates :5 soluble salts are treat$ ) a solution ( a soluble c>bonate4 ,?us ! insoluble calcium c>bonate c be made by br++ toge!r solutions ( calcium *loride & sodium c>bonate3 ,ca,cl#b ,na#b;,,co#c ,ca,c,o#c #b,na,cl4 ,mo/ ( ! c>bonates are decompos$ by heat1 yield+ an oxide ( ! metal & c>bon dioxide4 ,?us lime 7calcium oxide7 is made by /rongly heat+ calcium c>bonate3 ,ca,c,o#c ,ca,o ,,co#b4 ,acid c>bonates4 ,l all acids conta9+ two acid hydrog5 atoms1 c>bonic acid c =m bo? normal & acid salts4 ,! acid c>bonates are made by treat+ a normal c>bonate ) an excess ( c>bonic acid4 ,) few exceptions !y are v un/able1 heat decompos+ !m ev5 :5 9 solution4 ,action ( c>bon dioxide on calcium hydroxide4 ,if c>bon dioxide is pass$ into cle> lime wat]1 calcium c>bonate is at fir/ precipitat$3 ,h#b,o ,,co#b ,h#b;,,co#c1 ,ca7,,oh7#b ,h#b;,,co#c ,ca,c,o#c #b;,h#b,o4 ,advantage is tak5 ( ?is reaction 9 te/+ = ! pres5ce ( c>bon dioxide1 z already expla9$ 9 ! *apt] on ! atmosph]e4 ,if ! curr5t ( c>bon dioxide is cont9u$1 ! precipitate soon dissolves1 because ! excess ( c>bonic acid =ms calcium acid c>bonate :i* is soluble3 ,ca,c,o#c ,h#b;,,co#c ,ca7,,hco#c7b4 ,if n[ ! solution is heat$1 ! acid c>bonate is decompos$ & calcium c>bonate once m precipitat$3 ,ca7,,hco#c7b ,ca,c,o#c ,h#b;,,co#c4 ,c>bon monoxide 7,,co74 ,c>bon monoxide c be made 9 a numb] ( ways1 ! mo/ important ( :i* are ! ?ree foll[+3 #a4 ,by ! p>tial oxidation ( c>bon4 ,if a sl[ curr5t ( air is conduct$ ov] highly heat$ c>bon1 ! monoxide is =m$1 ?us3 ,c ,o ,,co ,x is !re=e (t5 =m$ 9 /oves :5 ! air draught is insuffici5t4 ,wat] gas1 :i* conta9s l>ge am\nts ( c>bon monoxide1 is made by p>tially oxidiz+ c>bon ) /eam3 ,c ,h#b,o ,,co #b;,h4 #b4 ,by ! p>tial r$uction ( c>bon dioxide4 ,:5 c>bon dioxide is conduct$ ov] highly heat$ c>bon x is r$uc$ to c>bon monoxide by ! excess ( c>bon3 ,,co#b ,c #b;,,co4 ,:5 coal is burn+ 9 a /ove or grate c>bon dioxide is at fir/ =m$ 9 ! free supply ( air1 b z ! hot gas rises ?r\gh ! gl[+ coal x is r$uc$ to c>bon monoxide4 ,:5 ! c>bon monoxide rea*es ! free air above ! coal x takes up oxyg5 to =m c>bon dioxide1 burn+ ) ! blue flame s famili> above a b$ ( coals1 especially 9 ! case ( h>d coals4 #c4 ,by ! decomposition ( oxalic acid4 ,9 ! laboratory c>bon monoxide is usually prep>$ by ! action ( conc5trat$ sulphuric acid ^u oxalic acid4 ,! latt] sub/ance has ! =mula ,c#b;,h#b,o#d4 ,! sulphuric acid1 ow+ to its aff9ity = wat]1 decomposes ! oxalic acid1 z repres5t$ 9 ! equation ,c#b;,h#b,o#d 7,h#b,,s#d7 7,h#b,,s#d7 ,h#b,o ,,co#b ,,co4 ,prop]ties4 ,c>bon monoxide is a light1 colorless1 almo/ odorless gas1 v difficult to liquefy4 ,*emically x is v active1 comb9+ directly ) a great _m sub/ances4 ,x has a great aff9ity = oxyg5 & is !re=e combu/ible & a good r$uc+ ag5t4 ,?us1 if c>bon monoxide is pass$ ov] hot copp] oxide1 ! copp] is r$uc$ to ! metallic /ate3 ,cu,o ,,co ,cu ,,co#b4 ,:5 inhal$ x comb9es ) ! r$ color+ matt] ( ! blood & 9 ?is way prev5ts ! absorption ( oxyg51 s t ev5 a small quantity ( ! gas may prove fatal4 ,illu/ration3 ,fig4 #fa ,! r$uc+ p[] ( c>bon monoxide4 ,fig4 #fa illu/rates a me?od ( %[+ ! r$uc+ p[] ( c>bon monoxide4 ,! gas is g5]at$ by g5tly heat+ #g or #h g4 ( oxalic acid ) #be cc4 ( conc5trat$ sulphuric acid 9 a #bjj cc4 flask ,a4 ,! bottle ,b conta9s a solution ( sodium hydroxide1 :i* removes ! c>bon dioxide =m$ along ) ! monoxide4 ,c conta9s a solution ( calcium hydroxide to %[ t ! c>bon dioxide is completely remov$4 ,e is a h>d-glass tube conta9+ #a or #b g4 ( copp] oxide1 :i* is heat$ by a burn]4 ,! black copp] oxide is r$uc$ to r$di% metallic copp] by ! c>bon monoxide1 :i* is !reby *ang$ to c>bon dioxide4 ,! pres5ce ( ! c>bon dioxide is %[n by ! precipitate 9 ! calcium hydroxide solution 9 ,d4 ,any un*ang$ c>bon monoxide is collect$ ov] wat] 9 ,f4 ,c>bon disulphide 7,,cs#b74 ,j z c>bon comb9es ) oxyg5 to =m c>bon dioxide1 s x comb9es ) sulphur to =m c>bon disulphide 7,,cs#b74 ,?is comp\nd has be5 describ$ 9 ! *apt] on sulphur4 ,hydrocyanic acid 7prussic acid77,,hcn74 ,"u ! prop] conditions c>bon unites ) nitrog5 & hydrog5 to =m ! acid ,,hcn1 call$ hydrocyanic acid4 ,x is a weak1 volatile acid1 & is !re=e easily prep>$ by treat+ its salts ) sulphuric acid3 ,,kcn ,h#b,,s#d ,,khso#d ,,hcn4 ,x is mo/ famili> z a gas1 ?\gh x cond5ses to a colorless liquid boil+ at #bf4 ,x has a peculi> odor1 sugge/+ bitt] almonds1 & is extremely poison\s ei!r :5 inhal$ or :5 tak5 into ! /oma*4 ,a s+le drop may cause dea?4 ,x dissolves readily 9 wat]1 its solution be+ commonly call$ prussic acid4 ,! salts ( hydrocyanic acid are call$ cyanides1 ! cyanides ( sodium & potassium be+ ! be/ kn[n4 ,^! are :ite solids & are extremely poison\s4 ,solutions ( potassium cyanide are alkal9e4 ,a solution ( potassium cyanide turns r$ litmus blue1 & mu/ !re=e conta9 hydroxyl ions4 ,! pres5ce ( ^! ions is acc\nt$ = 9 ! foll[+ way4 ,al?\gh wat] is s little dissociat$ into its ions ,h & ,,oh- t = mo/ purposes we may neglect ! dissociation1 x is nev]!less measurably dissociat$4 ,hydrocyanic acid is "o ( ! weake/ ( acids1 & dissociates to an extremely slight ext5t4 ,:5 a cyanide su* z potassium cyanide dissolves x freely dissociates1 & ! ,,cn- ions mu/ come to an equilibrium ) ! ,h ions d]iv$ f ! wat]3 ,h ,,cn- -- ,,hcn4 ,! result ( ?is equilibrium is t q a numb] ( ,h ions f ! wat] are conv]t$ into undissociat$ ,,hcn molecules4 ,b = e ,h ion s remov$ an ,,oh- ion rema9s free1 & ?is w give ! solution alkal9e prop]ties4 ,,ex]cises #a4 ,h[ c y prove t ! composition ( ! diff]5t allotropic =ms ( c>bon is ! same8 #b4 ,are lampblack & bone black allotropic =ms ( c>bon8 ,w equal am\nts ( heat be lib]at$ 9 ! combu/ion ( #a g4 ( ea*8 #c4 ,h[ c\ld y judge ( ! relative purity ( diff]5t =ms ( c>bon8 #d4 ,ap>t f its color1 :y %\ld c>bon be useful 9 ! prep>ation ( inks & pa9ts8 #e4 ,c\ld asbe/os fib]s be us$ to replace ! wire 9 a safety lamp8 #f4 ,:y d mo/ acids decompose c>bonates8 #g4 ,:at effect w\ld d\bl+ ! pressure h ^u ! solubility ( c>bon dioxide 9 wat]8 #h4 ,:at comp\nd w\ld be =m$ by pass+ c>bon dioxide into a solution ( ammonium hydroxide8 ,write ! equation4 #i4 ,write equations = ! prep>ation ( ,k#b;,,co#c2 ( ,ba,c,o#c2 ( ,mg,c,o#c4 #aj4 ,9 :at respects are c>bonic & sulphur\s acids simil>8 #aa4 ,give ?ree reasons :y ! reaction :i* takes place :5 a solution ( calcium acid c>bonate is heat$1 completes itself4 #ab4 ,h[ c\ld y di/+ui% betwe5 c>bonates & sulphites8 #ac4 ,h[ c\ld y di/+ui% betwe5 oxyg51 hydrog51 nitrog51 nitr\s oxide1 & c>bon dioxide8 #ad4 ,c\ld a solution ( sodium hydroxide be sub/itut$ = ! solution ( calcium hydroxide 9 te/+ = c>bon dioxide8 #ae4 ,:at weight ( sodium hydroxide is necess>y to neutralize ! c>bonic acid =m$ by ! action ( hydro*loric acid on #ajj g4 ( calcium c>bonate8 #af4 ,:at weight ( calcium c>bonate w\ld be necess>y to prep>e suffici5t c>bon dioxide to saturate #aj l4 ( wat] at #ae & "u ord9>y pressure8 #ag4 ,on ! supposition t calcium c>bide co/s #ab c5ts a kilogram1 :at w\ld be ! co/ ( an am\nt suffici5t to g5]ate #ajj l4 ( acetyl5e measur$ at #bj & #gdj mm48 #ah4 ,h[ w\ld ! volume ( a def9ite am\nt ( c>bon monoxide comp>e ) ! volume ( c>bon dioxide =m$ by its combu/ion1 ! measurem5ts be+ made "u ! same conditions8 ,,*apt] ,,xviii ,,flames1--,,illum9ants ,conditions necess>y = flames4 ,x has be5 se5 t :5 two sub/ances unite *emically1 ) ! production ( light & heat1 ! act ( union is call$ combu/ion4 ,:5 "o ( ! sub/ances und]go+ combu/ion rema9s solid at ! temp]ature occasion$ by ! combu/ion1 light may be giv5 (f1 b !re is no flame4 ,?us iron wire burn+ 9 oxyg5 ?r[s (f a %[] ( sp>ks & is brilliantly inc&esc5t1 b no flame is se54 ,:51 h[ev]1 bo? ( ! sub/ances are gases or vapors at ! temp]ature rea*$ 9 ! combu/ion1 ! act ( union is accompani$ by a flame4 ,flames f burn+ liquids or solids4 ,_m sub/ances :i* are liquids or solids at ord9>y temp]atures burn ) a flame because ! heat ( combu/ion vaporizes !m sl[ly1 & ! flame is due to ! union ( ?is vapor ) ! gas support+ ! combu/ion4 ,support] ( combu/ion4 ,t gas :i* surr\nds ! flame & con/itutes ! atmosph]e 9 :i* ! combu/ion occurs is said to support ! combu/ion4 ,! o!r gas :i* issues into ?is atmosph]e is said to be ! combu/ible gas4 ,?us1 9 ! ord9>y combu/ion ( coal gas 9 ! air ! coal gas is said to be combu/ible1 :ile ! air is reg>d$ z ! support] ( combu/ion4 ,^! t]ms are entirely relative1 h[ev]1 = a jet ( air issu+ into an atmosph]e ( coal gas w burn :5 ignit$1 ! coal gas support+ ! combu/ion4 ,ord9>ily1 :5 we say t a gas is combu/ible we mean t x is combu/ible 9 an atmosph]e ( air4 ,illu/ration3 ,fig4 #fb ,ei!r gas may be ! support] ( combu/ion4 ,t ! t]ms combu/ible & support] ( combu/ion are m]ely relative may be %[n 9 ! foll[+ way3 ,a lamp *imney ,a is fitt$ ) a cork & glass tubes1 z %[n 9 ,fig4 #fb4 ,! tube ,c %\ld h a diamet] ( f #ab to #ae mm4 ,a ?9 %eet ( asbe/os 9 :i* is cut a circul> op5+ ab\t #b cm4 9 diamet] is plac$ ov] ! top ( ! *imney4 ,! op5+ 9 ! asbe/os is clos$ ) ! palm ( ! h&1 & gas is admitt$ to ! *imney ?r\gh ! tube ,b4 ,! air 9 ! *imney is soon expell$ ?r\gh ! tube ,c1 & ! gas itself is !n light$ at ! l[] end ( ?is tube4 ,! h& is n[ remov$ f ! op5+ 9 ! asbe/os1 :5 ! flame at ! end ( ! tube at once rises & appe>s at ! end )9 ! *imney1 z %[n 9 ! figure4 ,! excess ( coal gas n[ escapes f ! op5+ 9 ! asbe/os & may be light$4 ,! flame at ! top ( ! asbe/os bo>d is due to ! combu/ion ( coal gas 9 air1 :ile ! flame )9 ! *imney is due to ! combu/ion ( air 9 coal gas1 ! air be+ drawn up ?r\gh ! tube by ! escap+ gas4 ,appe>ance ( flames4 ,! flame caus$ by ! union ( hydrog5 & oxyg5 is almo/ colorless & invisible4 ,*lor9e & hydrog5 comb9e ) a pale violet flame1 c>bon monoxide burns 9 oxyg5 ) a blue flame1 :ile ammonia burns ) a deep yell[ flame4 ,! color & appe>ance ( flames are !re=e (t5 q *>act]i/ic ( ! p>ticul> combu/ion :i* occasions !m4 ,/ructure ( flames4 ,:5 ! gas und]go+ combu/ion issues f a r\nd op5+ into an atmosph]e ( ! gas support+ combu/ion1 z is ! case ) ! burn+ ,buns5 burn] 7,fig4 #fc71 ! flame is g5]ally conical 9 outl9e4 ,x consi/s ( sev]al di/9ct cones1 "o )9 ! o!r1 ! b\nd>y betwe5 !m be+ m>k$ by diff]5ces ( color or lum9osity4 ,9 ! simple/ flame1 ( :i* hydrog5 burn+ 9 oxyg5 is a good example1 ^! cones are two 9 numb]1--an inn] "o1 =m$ by unburn$ gas1 & an out] "o1 usually m or less lum9\s1 consi/+ ( ! comb9+ gases4 ,?is out] "o is 9 turn surr\nd$ by a ?ird envelope ( ! products ( combu/ion2 ?is envelope is sometimes invisible1 z 9 ! pres5t case1 b is sometimes fa9tly lum9\s4 ,! l[] "p ( ! inn] cone ( ! flame is q cool & consi/s ( unburn$ gas4 ,t[>d ! top ( ! inn] cone ! gas has become heat$ to a high temp]ature by ! burn+ envelope surr\nd+ x4 ,on rea*+ ! support] ( combu/ion on ! outside x is f> above its k9dl+ temp]ature1 & combu/ion foll[s ) ! evolution ( mu* heat4 ,! region ( combu/ion j outside ! inn] cone is !re=e ! hotte/ "p ( ! flame4 ,illu/ration3 ,fig4 #fc ,oxidiz+ & r$uc+ flames4 ,s9ce ! tip ( ! outside cone consi/s ( v hot products ( combu/ion mix$ ) oxyg5 f ! air1 a sub/ance capable ( oxidation plac$ 9 ?is "p ( ! flame becomes v hot & is easily oxidiz$4 ,! oxyg5 ) :i* x comb9es comes1 ( c\rse1 f ! atmosph]e1 & n f ! products ( combu/ion4 ,?is out] tip ( ! flame is call$ ! oxidiz+ flame4 ,at ! tip ( ! inn] cone ! conditions are q diff]5t4 ,?is region consi/s ( a highly heat$ combu/ible gas1 :i* has n yet rea*$ a supply ( oxyg54 ,if a sub/ance ri* 9 oxyg51 su* z a metallic oxide1 is plac$ 9 ?is region ( ! flame1 ! heat$ gases comb9e ) its oxyg5 & ! sub/ance is r$uc$4 ,?is "p ( ! flame is call$ ! r$uc+ flame4 ,^! flames are us$ 9 te/+ c]ta9 sub/ances1 especially m9]als4 ,= ?is purpose !y are produc$ by bl[+ into a small lum9\s ,buns5 flame f "o side ?r\gh a bl[pipe4 ,?is is a tube ( ! %ape %[n 9 ,fig4 #fd4 ,! flame is direct$ 9 any desir$ way & has ! oxidiz+ & r$uc+ regions v cle>ly m>k$ 7,fig4 #fe74 ,x is non-lum9\s f ! same causes :i* r5d] ! op5 ,buns5 burn] flame non-lum9\s1 ! gases f ! lungs s]v+ to furni% oxyg5 & to dilute ! combu/ible gas4 ,illu/ration3 ,fig4 #fd ,illu/ration3 ,fig4 #fe ,lum9osity ( flames4 ,! lum9osity ( flames is due to a numb] ( di/9ct causes1 & may !re=e be increas$ or dim9i%$ 9 sev]al ways4 #a4 ,pres5ce ( solid matt]4 ,! mo/ obvi\s ( ^! causes is ! pres5ce 9 ! flame ( inc&esc5t solid matt]4 ,?us *alk du/ sift$ into a non-lum9\s flame r5d]s x lum9\s4 ,:5 hydroc>bons =m a "p ( ! combu/ible gas1 z !y d 9 ne>ly all illum9at+ gases & oils1 "s c>bon is usually set free 9 ! process ( combu/ion4 ,?is is made v hot by ! flame & becomes inc&esc5t1 giv+ out light4 ,9 a well-regulat$ flame x is aft]w>d burn$ up1 b :5 ! supply ( oxyg5 is insuffici5t x escapes f ! flame z lampblack or soot4 ,t x is tempor>ily pres5t 9 a well-burn+ lum9\s flame may be demon/rat$ by hold+ a cold object1 su* z a small evaporat+ di%1 9 ! flame = a few seconds4 ,?is cold object cools ! c>bon bel[ its k9dl+ temp]ature1 & x is deposit$ on ! object z soot4 #b4 ,pressure4 ,a second factor 9 ! lum9osity ( flames is ! pressure "u :i* ! gases are burn+4 ,"u increas$ pressure !re is m matt] 9 a giv5 volume ( a gas1 & ! *emical action is m en]getic ?an :5 ! gases are r>efi$4 ,consequ5tly !re is m heat & light4 ,a c&le burn+ on a high m\nta9 gives less light ?an :5 x burns at ! sea level4 ,if ! gas is dilut$ ) a non-combu/ible gas1 ! effect is ! same z if x is r>efi$1 = "u ^! conditions !re is less combu/ible gas 9 a giv5 volume4 #c4 ,temp]ature4 ,! lum9osity also dep5ds ^u ! temp]ature atta9$ 9 ! combu/ion4 ,9 g5]al ! hott] ! flame ! great] ! lum9osity2 h5ce cool+ ! gases be=e combu/ion dim9i%es ! lum9osity ( ! flame !y w make1 because x dim9i%es ! temp]ature atta9$ 9 ! combu/ion4 ,?us ! lum9osity ( ! ,buns5 flame is l>gely dim9i%$ by ! air drawn up ) ! gas4 ,?is is due 9 "p to ! fact t ! burn+ gas is dilut$ & cool$ by ! air drawn 94 ,! oxyg5 ?us introduc$ into ! flame also causes ! combu/ion ( ! hot p>ticles ( c>bon :i* w\ld o!rwise t5d to make ! flame lum9\s4 ,illum9at+ & fuel gases4 ,a numb] ( mixtures ( combu/ible gases1 consi/+ l>gely ( c>bon comp\nds & hydrog51 f9d ext5sive use = ! production ( light & heat4 ,! ?ree *ief v>ieties are coal gas1 wat] gas1 & natural gas4 ,! use ( acetyl5e gas has already be5 ref]r$ to4 ,coal gas4 ,coal gas is made by heat+ bitum9\s coal 9 l>ge retorts out ( contact ) ! air4 ,s(t or bitum9\s coal conta9s1 9 addition to l>ge am\nts ( c>bon1 consid]able quantities ( comp\nds ( hydrog51 oxyg51 nitrog51 & sulphur4 ,:5 di/ill$ ! nitrog5 is lib]at$ p>tly 9 ! =m ( ammonia & cyanides & p>tly z free nitrog5 gas2 ! sulphur is conv]t$ into hydrog5 sulphide1 c>bon disulphide1 & oxides ( sulphur2 ! oxyg5 into wat] & oxides ( c>bon4 ,! rema9+ hydrog5 is set free p>tly z hydrog5 & p>tly 9 comb9ation ) c>bon 9 ! =m ( hydroc>bons4 ,! mo/ important ( ^! is me?ane1 ) small] quantities ( _m o!rs1 "s ( :i* are liquids or solids at ord9>y temp]atures4 ,! great bulk ( ! c>bon rema9s beh9d z coke & retort c>bon4 ,! manufacture ( coal gas4 ,9 ! manufacture ( coal gas x is necess>y to sep>ate f ! volatile con/itu5ts =m$ by ! heat+ ( ! coal all ^? sub/ances :i* are ei!r solid or liquid at ord9>y temp]ature1 s9ce ^! w\ld clog ! gas pipes4 ,c]ta9 gase\s con/itu5ts1 su* z hydrog5 sulphide & ammonia1 mu/ also be remov$4 ,! me?od us$ to accompli% ?is is %[n 9 ,fig4 #ff4 ,! coal is heat$ 9 air-tight retorts illu/rat$ by ,a4 ,! volatile products escape ?r\gh ! pipe ,x & bubble into ! t>ry liquid 9 ! l>ge pipe ,b1 kn[n z ! hydraulic ma91 :i* runs at "r angles to ! retorts4 ,"h is deposit$ ! great] portion ( ! solid & liquid products1 =m+ a t>ry mass kn[n z coal t>4 ,mu* ( ! ammonia also rema9s dissolv$ 9 ?is liquid4 ,! p>tially purifi$ gas !n passes into ! pipes ,c1 :i* s]ve to cool x & fur!r remove ! solid & liquid matt]4 ,! gas !n passes into ,d1 :i* is fill$ ) coke ov] :i* a jet ( wat] is spray$4 ,! wat] /ill fur!r cools ! gas & at ! same "t p>tially removes su* gase\s products z hydrog5 sulphide & ammonia1 :i* are soluble 9 wat]4 ,9 ,e ! gas passes ov] "s mat]ial su* z lime1 :i* removes ! la/ portions ( ! sulphur comp\nds z well z mu* ( ! c>bon dioxide pres5t4 ,f ,e ! gas passes into ! l>ge gas hold] ,f1 f :i* x is di/ribut$ ?r\gh pipes to ! places :]e x is burn$4 ,illu/ration3 ,fig4 #ff ,"o ton ( good gas coal yields approximately #aj1jjj cu4 ft4 ( gas1 #adjj lb4 ( coke1 #abj lb4 ( t>1 & #bj gal4 ( ammoniacal liquor4 ,n only is ! ammonia obta9$ 9 ! manufacture ( ! gas ( great importance1 b ! coal t> also s]ves z ! s\rce ( _m v useful sub/ances1 z w be expla9$ 9 ,*apt] ,,xxxii4 ,wat] gas4 ,wat] gas is ess5tially a mixture ( c>bon monoxide & hydrog54 ,x is made by pass+ /eam ov] v hot an?racite coal1 :5 ! reaction %[n 9 ! foll[+ equation takes place3 ,c ,h#b,o ,,co #b;,h4 ,:5 requir$ m]ely to produce heat ! gas is at once ready = use4 ,:5 made = illum9at+ purposes x mu/ be enri*$1 t is1 illum9ants mu/ be add$1 s9ce bo? c>bon monoxide & hydrog5 burn ) non-lum9\s flames4 ,?is is accompli%$ by pass+ x into heat]s conta9+ highly heat$ petroleum oils4 ,! gas takes up hydroc>bon gases =m$ 9 ! decomposition ( ! petroleum oils1 :i* make x burn ) a lum9\s flame4 ,wat] gas is v effective z a fuel1 s9ce bo? c>bon monoxide & hydrog5 burn ) v hot flames4 ,x has little odor & is v poison\s4 ,its use is !re=e att5d$ ) "s risk1 s9ce leaks 9 pipes are v likely to escape notice4 ,natural gas4 ,?is sub/ance1 s abundant 9 _m localities1 v>ies mu* 9 composition1 b is compos$ pr9cipally ( me?ane4 ,:5 us$ = light+ purposes x is usually burn$ 9 a burn] resembl+ an op5 ,buns51 ! illum9ation be+ furni%$ by an inc&esc5t mantle4 ,?is is ! case 9 ! famili> ,welsba* burn]4 ,contr>y to /atem5ts frequ5tly made1 natural gas conta9s no free hydrog54 ,,table ,,%[+ ,,composition ,,( ,,gases ,,p5nsylvania ,,coal ,,wat] ,,enri*$ ,,natural ,,gas ,,gas ,,wat] ,,gas ,,gas ---------------------------------------- ----------------------- ,hydrog5 #da4c #eb4hh #cj4jj ,me?ane #ij4fd #dc4f #b4af #bd4jj ,illum9ants #c4i #ab4je ,c>bon monoxide #f4d #cf4hj #bi4jj ,c>bon dioxide #j4cj #b4j #c4dg #j4cj ,nitrog5 #i4jf #a4b #d4fi #b4ej ,oxyg5 #j4c #a4ej ,hydroc>bon vapors #a4e #a4ej ,^! are analyses ( actual samples1 & may be tak5 z ab\t ! av]age = ! v>i\s k9ds ( gases4 ,any "o ( ^! may v>y consid]ably4 ,! nitrog5 & oxyg5 9 mo/ cases is due to a slight admixture ( air :i* is difficult to exclude entirely 9 ! manufacture & h&l+ ( gases4 ,fuels4 ,a v>iety ( sub/ances are us$ z fuels1 ! mo/ important ( !m be+ wood1 coal1 & ! v>i\s gases m5tion$ above4 ,wood consi/s ma9ly ( comp\nds ( c>bon1 hydrog51 & oxyg54 ,! composition ( coal & ! fuel gases has be5 giv54 ,s9ce ^! fuels are compos$ pr9cipally ( c>bon & hydrog5 or _! comp\nds1 ! *ief products ( combu/ion are c>bon dioxide & wat]4 ,! practice ( heat+ rooms ) portable gas or oil /oves ) no provision = remov+ ! products ( combu/ion is to be condemn$1 s9ce ! c>bon dioxide is g5]at$ 9 suffici5t quantities to r5d] ! air unfit = brea?+4 ,rooms s heat$ also become v damp f ! l>ge am\nt ( wat] vapor =m$ 9 ! combu/ion1 & :i* 9 cold wea!r cond5ses on ! w9d[ glass1 caus+ ! glass to sweat4 ,bo? coal & wood conta9 a c]ta9 am\nt ( m9]al sub/ances :i* con/itute ! a%es4 ,! electric furnace4 ,9 rec5t ye>s electric furnaces h come into wide use 9 op]ations requir+ a v high temp]ature4 ,temp]atures z high z #cejj c be easily rea*$1 :]eas ! hotte/ oxyhydrog5 flame is n mu* above #bjjj4 ,^! furnaces are con/ruct$ on "o ( two g5]al pr9ciples4 ,illu/ration3 ,fig4 #fg #a4 ,arc furnaces4 ,9 ! "o type ! s\rce ( heat is an electric arc =m$ betwe5 c>bon electrodes sep>at$ a little f ea* o!r1 z %[n 9 ,fig4 #fg4 ,! sub/ance to be heat$ is plac$ 9 a vessel1 usually a graphite crucible1 j bel[ ! arc4 ,! electrodes & crucible are surr\nd$ by mat]ials :i* fuse ) great difficulty1 su* z magnesium oxide1 ! walls ( ! furnace be+ s %ap$ z to reflect ! heat d[nw>ds ^u ! cont5ts ( ! crucible4 ,illu/ration3 ,fig4 #fh #b4 ,resi/ance furnaces4 ,9 ! o!r type ( furnace ! heat is g5]at$ by ! resi/ance (f]$ to ! curr5t 9 its passage ?r\gh ! furnace4 ,9 its simple/ =m x may be repres5t$ by ,fig4 #fh4 ,! furnace is m]ely a rectangul> box built up ( loose bricks4 ,! electrodes ,e1 ea* consi/+ ( a bundle ( c>bon rods1 are introduc$ ?r\gh ! sides ( ! furnace4 ,! mat]ials to be heat$1 ,c1 are fill$ into ! furnace up to ! electrodes1 & a lay] ( brok5 coke is arrang$ s z to ext5d f "o electrode to ! o!r4 ,m ( ! *>ge is !n plac$ on top ( ! coke4 ,9 pass+ ?r\gh ! brok5 coke ! electrical curr5t enc\nt]s great resi/ance4 ,?is g5]ates great heat1 & ! *>ge surr\nd+ ! coke is br\ght to a v high temp]ature4 ,! advantage ( ?is type ( furnace is t ! temp]ature c be regulat$ to any desir$ int5sity4 ,,ex]cises #a4 ,:y does *>coal usually burn ) no flame8 ,h[ d y acc\nt = ! flame sometimes obs]v$ :5 x burns8 #b4 ,h[ d y acc\nt = ! fact t a c&le burns ) a flame8 #c4 ,:at two prop]ties mu/ ! mantle us$ 9 ! ,welsba* lamp possess8 #d4 7a7 ,9 :at respects does ! use ( ! ,welsba* mantle resemble t ( lime 9 ! calcium light8 7b7 ,if ! mantle 7 made ( c>bon1 w\ld x s]ve ! same purpose8 #e4 ,w\ld an?racite coal be suitable = ! manufacture ( coal gas8 #f4 ,h[ c\ld y prove ! =mation ( c>bon dioxide & wat] 9 ! combu/ion ( illum9at+ gases8 #g4 ,sugge/ a probable way 9 :i* natural gas has be5 =m$4 #h4 ,coal frequ5tly conta9s a sulphide ( iron4 7a7 ,:at two sulphur comp\nds are likely to be =m$ :5 gas is made f su* coal8 7b7 ,sugge/ "s suitable me?od = ! removal ( ^! comp\nds4 #i4 ,:y does ! use ( ! bell[s on ! blacksmi?'s =ge cause a m int5se heat8 #aj4 ,:at volume ( oxyg5 is necess>y to burn #ajj l4 ( m>% gas & :at volume ( c>bon dioxide w\ld be =m$1 all ( ! gases be+ measur$ "u /&>d conditions8 #aa4 ,suppose a cubic met] ( ,p5nsylvania natural gas1 measur$ "u /&>d conditions1 7 to be burn$4 ,h[ mu* wat] by weight w\ld result8 ,,*apt] ,,xix ,,molecul> ,,weights1 ,,atomic ,,weights1 ,,=mulas ,introduction4 ,9 ! *apt] on ,! ,atomic ,!ory1 x 0 %[n t if x 7 true t two elem5ts unit+ to =m a comp\nd always comb9$ 9 ! ratio ( "o atom ( "o elem5t to "o atom ( ! o!r elem5t1 x w\ld be a v easy matt] to decide ^u figures :i* w\ld repres5t ! relative weights ( ! diff]5t atoms4 ,x w\ld only be necess>y to select "s "o elem5t z a /&>d & det]m9e ! weight ( e elem5t :i* comb9es ) a def9ite weight 7say #a g47 ( ! /&>d elem5t4 ,! figures s obta9$ w\ld evid5tly repres5t ! relative weights ( ! atoms4 ,b ! law ( multiple proportion at once rem9ds u t two elem5ts may unite 9 sev]al proportions2 & !re is no simple way to det]m9e ! numb] ( atoms pres5t 9 ! molecule ( any comp\nd4 ,consequ5tly ! problem ( decid+ ^u ! relative atomic weights is n an easy "o4 ,to ! solution ( ?is problem we mu/ n[ turn4 ,dalton's me?od ( det]m9+ atomic weights4 ,:5 ,dalton fir/ advanc$ ! atomic !ory he attempt$ to solve ?is problem by v simple me?ods4 ,he ?\ght t :5 only "o comp\nd ( two elem5ts is kn[n x is reasonable to suppose t x conta9s "o atom ( ea* elem5t4 ,he !re=e gave ! =mula ,,ho to wat]1 & ,,hn to ammonia4 ,:5 m ?an two comp\nds 7 kn[n he assum$ t ! mo/ famili> or ! mo/ /able "o _h ! simple =mula4 ,he !n det]m9$ ! atomic weight z expla9$ above4 ,! results he obta9$ 7 contradictory & v f> f satisfactory1 & x 0 soon se5 t "s o!r me?od1 re/+ on mu* m sci5tific gr\nds1 mu/ be f\nd to decide :at comp\nds1 if any1 h a s+le atom ( ea* elem5t pres5t4 ,det]m9ation ( atomic weights4 ,?ree di/9ct /eps are involv$ 9 ! det]m9ation ( ! atomic weight ( an elem5t3 7#a7 det]m9ation ( ! equival5t1 7#b7 det]m9ation ( molecul> weights ( its comp\nds1 & 7#c7 d$uction ( ! exact atomic weight f ! equival5t & molecul> weights4 #a4 ,det]m9ation ( ! equival5t4 ,by ! equival5t ( an elem5t is meant ! weight ( ! elem5t :i* w comb9e ) a fix$ weight ( "s o!r elem5t *os5 z a /&>d4 ,x has already be5 expla9$ t oxyg5 has be5 select$ z ! /&>d elem5t = atomic weights1 ) a weight ( #af4 ,?is same /&>d w s]ve v well z a /&>d = equival5ts4 ,! equival5t ( an elem5t is ! weight ( ! elem5t :i* w comb9e ) #af g4 ( oxyg54 ,?us #af g4 ( oxyg5 comb9es ) #af4jc g4 ( sulphur1 #fe4d g4 ( z9c1 #bae4hf g4 ( silv]1 #gj4i g4 ( *lor9e4 ,^! figures1 !re=e1 repres5t ! equival5t weights ( ^! elem5ts4 ,relation ( atomic weights to equival5ts4 ,accord+ to ! atomic !ory comb9ation always takes place betwe5 :ole numb]s ( atoms4 ,?us "o atom unites ) "o o!r1 or ) two or ?ree2 or two atoms may unite ) ?ree1 or ?ree ) five1 & s on4 ,:5 oxyg5 comb9es ) z9c ! comb9ation mu/ be betwe5 def9ite numb]s ( ! two k9ds ( atoms4 ,exp]im5t %[s t ^! two elem5ts comb9e 9 ! ratio ( #af g4 ( oxyg5 to #fe4d g4 ( z9c4 ,if "o atom ( oxyg5 comb9es ) "o atom ( z9c1 !n ?is ratio mu/ be ! ratio betwe5 ! weights ( ! two atoms4 ,if "o atom ( oxyg5 comb9es ) two atoms ( z9c1 !n ! ratio betwe5 ! weights ( ! two atoms w be #af3 #cb4g4 ,if two atoms ( oxyg5 comb9e ) "o atom ( z9c1 ! ratio by weight betwe5 ! two atoms w be #h3 #fe4d4 ,x is evid5t1 !re=e1 t ! real atomic weight ( an elem5t mu/ be "s multiple or submultiple ( ! equival5t2 9 o!r words1 ! equival5t multipli$ by #a_/b1 #a1 #b1 or #c w give ! atomic weight4 ,comb9+ weights4 ,a v int]e/+ relation holds good betwe5 ! equival5ts ( ! v>i\s elem5ts4 ,we h j se5 t ! figures #af4jc1 #fe4d1 #bae4hf1 & #gj4i are ! equival5ts respectively ( sulphur1 z9c1 silv]1 & *lor9e4 ,^! same figures repres5t ! ratios by weight 9 :i* ^! elem5ts comb9e among !mselves4 ,?us #bae4hf g4 ( silv] comb9e ) #gj4i g4 ( *lor9e & ) #b #af4jc g4 ( sulphur4 #fe4d g4 ( z9c comb9e ) #gj4i g4 ( *lor9e & #b #af4jc g4 ( sulphur4 ,by tak+ ! equival5t or "s multiple ( x a value c be obta9$ = ea* elem5t :i* w repres5t its comb9+ value1 & = ?is reason is call$ its comb9+ weight4 ,x is important to notice t ! fact t a comb9+ weight c be obta9$ = ea* elem5t is n a "p ( a !ory1 b is ! direct result ( exp]im5t4 ,elem5ts ) m ?an "o equival5t4 ,x w be rememb]$ t oxyg5 comb9es ) hydrog5 9 two ratios4 ,9 "o case #af g4 ( oxyg5 comb9e ) #b4jaf g4 ( hydrog5 to =m wat]2 9 ! o!r #af g4 ( oxyg5 comb9e ) #a4jjh g4 ( hydrog5 to =m hydrog5 dioxide4 ,! equival5ts ( hydrog5 are !re=e #b4jaf & #a4jjh4 ,b>ium comb9es ) oxyg5 9 two proportions3 9 b>ium oxide ! proportion is #af g4 ( oxyg5 to #acg4d g4 ( b>ium2 9 b>ium dioxide ! proportion is #af g4 ( oxyg5 to #fh4g g4 ( b>ium4 ,9 ea* case "o equival5t is a simple multiple ( ! o!r1 s ! fact t !re may be two equival5ts does n add to ! unc]ta9ty4 ,all we knew be=e 0 t ! true atomic weight is "s multiple ( ! equival5t4 #b4 ,! det]m9ation ( molecul> weights4 ,to decide ! "q z to :i* multiple ( ! equival5t correctly repres5ts ! atomic weight ( an elem5t1 x has be5 f\nd necess>y to devise a me?od ( det]m9+ ! molecul> weights ( comp\nds conta9+ ! elem5t 9 "q4 ,s9ce ! molecul> weight ( a comp\nd is m]ely ! sum ( ! weights ( all ! atoms pres5t 9 x1 x w\ld seem to be impossible to det]m9e ! molecul> weight ( a comp\nd )\t fir/ kn[+ ! atomic weights ( ! con/itu5t atoms1 & h[ _m atoms ( ea* elem5t are pres5t 9 ! molecule4 ,b c]ta9 facts h be5 discov]$ :i* sugge/ a way 9 :i* ?is c be done4 ,avogadro's hypo!sis4 ,we h se5 t ! laws ( ,boyle1 ,*>les1 & ,gay-,lussac apply to all gases irrespective ( _! *emical "*4 ,?is w\ld lead to ! inf]5ce t ! /ructure ( gases mu/ be q simple1 & t x is mu* ! same 9 all gases4 ,9 #ahaa ,avogadro1 an ,italian physici/1 sugge/$ t if we assume all gases "u ! same conditions ( temp]ature & pressure to h ! same numb] ( molecules 9 a giv5 volume1 we %all h a probable explanation ( ! simplicity ( ! gas laws4 ,x is difficult to prove ! tru? ( ?is hypo!sis by a simple exp]im5t1 b !re are s _m facts kn[n :i* are 9 complete h>mony ) ?is sugge/ion t !re is little d\bt t x expresses ! tru?4 ,avogadro's hypo!sis may be /at$ ?us3 ,equal volumes ( all gases "u ! same conditions ( temp]ature & pressure conta9 ! same numb] ( molecules4 ,avogadro's hypo!sis & molecul> weights4 ,assum+ t ,avogadro's hypo!sis is correct1 we h a v simple means = decid+ ^u ! relative weights ( molecules2 = if equal volumes ( two gases conta9 ! same numb] ( molecules1 ! weights ( ! two volumes mu/ be 9 ! same ratio z ! weights ( ! individual molecules :i* !y conta94 ,if we adopt "s "o gas z a /&>d1 we c express ! weights ( all o!r gases z comp>$ ) ?is "o1 & ! same figures w express ! relative weights ( ! molecules ( :i* ! gases are compos$4 ,oxyg5 z ! /&>d4 ,x is important t ! same /&>d %\ld be adopt$ = ! det]m9ation ( molecul> weights z has be5 decid$ ^u = atomic weights & equival5ts1 s t ! ?ree values may be 9 h>mony ) ea* o!r4 ,accord+ly x is be/ to adopt oxyg5 z ! /&>d elem5t ) :i* to comp>e ! molecul> weights ( o!r gases1 be+ c>eful to keep ! oxyg5 atom equal to #af4 ,! oxyg5 molecule conta9s two atoms4 ,"o po9t mu/ n be ov]look$1 h[ev]4 ,we desire to h our unit1 ! oxyg5 atom1 equal to #af4 ,! me?od ( comp>+ ! weights ( gases j sugge/$ comp>es ! molecules ( ! gases ) ! molecule ( oxyg54 ,is ! molecule & ! atom ( oxyg5 ! same ?+8 ,?is "q is answ]$ by ! foll[+ consid]ations4 ,we h se5 t :5 /eam is =m$ by ! union ( oxyg5 & hydrog51 two volumes ( hydrog5 comb9e ) "o volume ( oxyg5 to =m two volumes ( /eam4 ,let u suppose t ! "o volume ( oxyg5 conta9s #ajj molecules2 !n ! two volumes ( /eam mu/1 accord+ to ,avogadro's hypo!sis1 conta9 #bjj molecules4 ,b ea* ( ^! #bjj molecules mu/ conta9 at lea/ "o atom ( oxyg51 or #bjj 9 all1 & ^! #bjj atoms came f #ajj molecules ( oxyg54 ,x foll[s t ea* molecule ( oxyg5 mu/ conta9 at lea/ two atoms ( oxyg54 ,evid5tly ?is reason+ m]ely %[s t !re are at lea/ two atoms 9 ! oxyg5 molecule4 ,!re may be m ?an t1 b z !re is no evid5ce to ?is effect1 we assume t ! molecule conta9s two atoms only4 ,x is evid5t t if we wi% to reta9 ! value #af = ! atom ( oxyg5 we mu/ take twice ?is value1 or #cb1 = ! value ( ! oxyg5 molecule1 :5 us+ x z a /&>d = molecul> weights4 ,det]m9ation ( ! molecul> weights ( gases f _! weights comp>$ ) oxyg54 ,assum+ ! molecul> weight ( oxyg5 to be #cb1 ,avogadro's hypo!sis gives u a ready means = det]m9+ ! molecul> weight ( any o!r gas1 = all t is requir$ is to "k its weight comp>$ ) t ( an equal volume ( oxyg54 ,= example1 #a l4 ( *lor9e is f\nd by exp]im5t to weigh #b4baf times z mu* z #a l4 ( oxyg54 ,! molecul> weight ( *lor9e mu/ !re=e be #b4baf #cb1 or #gj4ia4 ,if1 in/ead ( comp>+ ! relative weights ( #a l4 ( ! two gases1 we select su* a volume ( oxyg5 z w weigh #cb g41 or ! weight 9 grams correspond+ to ! molecul> weight ( ! gas1 ! calculation is mu* simplifi$4 ,x has be5 f\nd t #cb g4 ( oxyg51 "u /&>d conditions1 measure #bb4d l4 ,?is same volume ( hydrog5 weighs #b4jai g42 ( *lor9e #gj4i g42 ( hydro*loric acid #cf4deh g4 ,! weights ( ^! equal volumes mu/ be proportional to _! molecul> weights1 & s9ce ! weight ( ! oxyg5 is ! same z ! value ( its molecul> weight1 s too w ! weights ( ! #bb4d l4 ( ! o!r gases be equal to ! value ( _! molecul> weights4 ,z a summ>y we c !n make ! foll[+ /atem5t3 ,! molecul> weight ( any gas may be det]m9$ by calculat+ ! weight ( #bb4d l4 ( ! gas1 measur$ "u /&>d conditions4 ,det]m9ation ( molecul> weights f d5sity ( gases4 ,9 an actual exp]im5t x is easi] to det]m9e ! d5sity ( a gas ?an ! weight ( a def9ite volume ( x4 ,! d5sity ( a gas is usually def9$ z its weight comp>$ ) t ( an equal volume ( air4 ,hav+ det]m9$ ! d5sity ( a gas1 its weight comp>$ ) oxyg5 may be det]m9$ by multiply+ its d5sity by ! ratio betwe5 ! weights ( air & oxyg54 ,?is ratio is #j4ijdf4 ,to comp>e x ) our /&>d = atomic weights we mu/ fur!r multiply x by #cb1 s9ce ! /&>d is #a_/cb ! weight ( oxyg5 molecules4 ,! /eps !n are ^!3 #a4 ,det]m9e ! d5sity ( ! gas 7its weight comp>$ ) air74 #b4 ,multiply by #j4ijdf to make ! comp>ison ) oxyg5 molecules4 #c4 ,multiply by #cb to make ! comp>ison ) ! unit = atomic weights4 ,we h1 !n1 ! =mula3 molecul> weight d5sity #j4ijdf #cb2 or1 /ill m briefly1 ,m4 ,d4 #bh4i4 ,! value f\nd by ?is me?od = ! det]m9ation ( molecul> weights w ( c\rse agree ) ^? f\nd by calculat+ ! weight ( #bb4d l4 ( ! gas1 s9ce bo? me?ods dep5d on ! same pr9ciples4 ,illu/ration3 ,fig4 #fi ,det]m9ation ( d5sities ( gases4 ,! relative weights ( equal volumes ( two gases c be easily det]m9$4 ,! foll[+ is "o ( ! me?ods us$4 ,a small flask1 su* z is %[n 9 ,fig4 #fi1 is fill$ ) "o ( ! gases1 & aft] ! temp]ature & pressure h be5 not$ ! flask is seal$ up & weigh$4 ,! tip ( ! seal$ end is !n brok5 (f1 ! flask fill$ ) ! second gas1 & its weight det]m9$4 ,if ! weight ( ! empty flask is subtract$ f ^! two weigh+s1 ! relative weights ( ! gases is readily f\nd4 #c4 ,d$uction ( atomic weights f molecul> weights & equival5ts4 ,we h n[ se5 h[ ! equival5t ( an elem5t & ! molecul> weight ( comp\nds conta9+ ! elem5t c be obta9$4 ,let u see h[ x is possible to decide :i* multiple ( ! equival5t really is ! true atomic weight4 ,z an example1 let u suppose t ! equival5t ( nitrog5 has be5 f\nd to be #g4jb & t x is desir$ to obta9 its atomic weight4 ,! next /ep is to obta9 ! molecul> weights ( a l>ge numb] ( comp\nds conta9+ nitrog54 ,! foll[+ w s]ve3 ,,approximate ,,p]c5tage ,,( ,,"p ,,( ,,d5sity ,,by ,,molecul> ,,nitrog5 ,,by ,,molecul> ,,exp]im5t ,,weight ,,exp]im5t ,,weight ,,due 7,d4 #bh4i7 ,,to ,,nitrog5 ---------------------------------------- --------------------------------- ,nitrog5 gas #j4ifga #bg4ie #ajj4jj #bg4ie ,nitr\s oxide #a4ebg #dd4ac #fc4gj #bg4aa ,nitric oxide #a4jchd #cj4jj #df4gd #ad4jb ,nitrog5 p]oxide #a4ehj #de4ff #cj4di #ac4ij ,ammonia #j4eia #ag4je #hb4bh #ad4jc ,nitric acid #b4ahj #fc4jf #bb4bg #ad4jc ,hydrocyanic acid #j4icj #bf4hg #ea4ij #ac4id ,me?od ( calculation4 ,! d5sities ( ! v>i\s gases 9 ! fir/ column ( ?is table are det]m9$ by exp]im5t1 & are fairly accurate b n entirely s4 ,by multiply+ ^! d5sities by #bh4i ! molecul> weights ( ! comp\nds z giv5 9 ! second column are obta9$4 ,by *emical analysis x is possible to det]m9e ! p]c5tage composition ( ^! sub/ances1 & ! p]c5tages ( nitrog5 9 !m z det]m9$ by analysis are giv5 9 ! ?ird column4 ,if ea* ( ^! molecul> weights is multipli$ 9 turn by ! p]c5tage ( nitrog5 9 ! comp\nd1 ! product w be ! weight ( ! nitrog5 9 ! molecul> weight ( ! comp\nd4 ,?is w be ! sum ( ! weights ( ! nitrog5 atoms 9 ! molecule4 ,^! values are giv5 9 ! f\r? column 9 ! table4 ,if a l>ge numb] ( comp\nds conta9+ nitrog5 are /udi$ 9 ?is way1 x is probable t !re w be includ$ 9 ! li/ at lea/ "o sub/ance ^: molecule conta9s a s+le nitrog5 atom4 ,9 ?is case ! numb] 9 ! f\r? column w be ! approximate atomic weight ( nitrog54 ,on comp>+ ! values = nitrog5 9 ! table x w be se5 t a numb] :i* is approximately #ad is ! smalle/1 & t ! o!rs are multiples ( ?is4 ,^! comp\nds ( high] value1 !re=e1 conta9 m ?an "o nitrog5 atom 9 ! molecule4 ,accurate det]m9ation ( atomic weights4 ,molecul> weights _c be det]m9$ v accurately1 & consequ5tly ! "p 9 !m due to nitrog5 is a little unc]ta91 z w be se5 9 ! table4 ,all we c tell by ?is me?od is t ! true weight is v ne> #ad4 ,! equival5t c h[ev] be det]m9$ v accurately1 & we h se5 t x is "s multiple or submultiple ( ! true atomic weight4 ,s9ce molecul>-weight det]m9ations h %[n t 9 ! case ( nitrog5 ! atomic weight is ne> #ad1 & we h f\nd ! equival5t to be #g4jb1 x is evid5t t ! true atomic weight is twice ! equival5t1 or #g4jb #b #ad4jd4 ,summ>y4 ,^!1 !n1 are ! /eps necess>y to e/abli% ! atomic weight ( an elem5t4 #a4 ,det]m9e ! equival5t accurately by analysis4 #b4 ,det]m9e ! molecul> weight ( a l>ge numb] ( comp\nds ( ! elem5t1 & by analysis ! "p ( ! molecul> weight due to ! elem5t4 ,! smalle/ numb] s obta9$ w be approximately ! atomic weight4 #c4 ,multiply ! equival5t by ! small :ole numb] 7usually #a1 #b1 or #c71 :i* w make a numb] v close to ! approximate atomic weight4 ,! figure s obta9$ w be ! true atomic weight4 ,molecul> weights ( ! elem5ts4 ,x w be notic$ t ! molecul> weight ( nitrog5 obta9$ by multiply+ its d5sity by #bh4i is #bh4jh4 ,yet ! atomic weight ( nitrog5 z d$uc$ f a /udy ( its gase\s comp\nds is #ad4jd4 ,! simple/ explanation t c be giv5 = ?is is t ! gase\s nitrog5 is made up ( molecules1 ea* ( :i* conta9s two atoms4 ,9 ?is respect x resembles oxyg52 = we h se5 t an entirely diff]5t l9e ( reason+ leads u to believe t ! molecule ( oxyg5 conta9s two atoms4 ,:5 we wi% to indicate molecules ( ^! gases ! symbols ,n#b & ,o#b %\ld be us$4 ,:5 we desire to m]ely %[ ! weights tak+ "p 9 a reaction ?is is n necess>y4 ,! vapor d5sities ( _m ( ! elem5ts %[ t1 l oxyg5 & nitrog51 _! molecules consi/ ( two atoms4 ,9 o!r cases1 p>ticul>ly among ! metals1 ! molecule & ! atom are id5tical4 ,/ill o!r elem5ts h f\r atoms 9 _! molecules4 ,:ile oxyg5 conta9s two atoms 9 its molecules1 a /udy ( ozone has l$ to ! conclusion t x has ?ree4 ,! =mation ( ozone f oxyg5 c !re=e be repres5t$ by ! equation #c,o#b #b,o#c4 ,o!r me?ods ( det]m9+ molecul> weights4 ,x w be notic$ t ,avogadro's law gives u a me?od by :i* we c det]m9e ! relative weights ( ! molecules ( two gases because x enables u to tell :5 we are deal+ ) an equal numb] ( ! two k9ds ( molecules4 ,if by any o!r means we c get ?is in=mation1 we c make use ( ! k s ga9$ to det]m9e ! molecul> weights ( ! two sub/ances4 ,ra\lt's laws4 ,two laws h be5 discov]$ :i* give u j su* in=mation4 ,!y are kn[n z ,ra\lt's laws1 & c be /at$ z foll[s3 #a4 ,:5 weights ( sub/ances :i* are proportional to _! molecul> weights are dissolv$ 9 ! same weight ( solv5t1 ! rise ( ! boil+ po9t is ! same 9 ea* case4 #b4 ,:5 weights ( sub/ances :i* are proportional to _! molecul> weights are dissolv$ 9 ! same weight ( solv5t1 ! l[]+ ( ! freez+ po9t is ! same 9 ea* case4 ,by tak+ advantage ( ^! laws x is possible to det]m9e :5 two solutions conta9 ! same numb] ( molecules ( two dissolv$ sub/ances1 & consequ5tly ! relative molecul> weights ( ! two sub/ances4 ,law ( ,dulong & ,petit4 ,9 #ahai ,dulong & ,petit discov]$ a v int]e/+ relation betwe5 ! atomic weight ( an elem5t & its specific heat1 :i* holds true = elem5ts 9 ! solid /ate4 ,if equal weights ( two solids1 say1 lead & silv]1 are heat$ ?r\gh ! same range ( temp]ature1 z f #aj to #bj1 x is f\nd t v diff]5t am\nts ( heat are requir$4 ,! am\nt ( heat requir$ to *ange ! temp]ature ( a solid or a liquid by a def9ite am\nt comp>$ ) ! am\nt requir$ to *ange ! temp]ature ( an equal weight ( wat] by ! same am\nt is call$ its specific heat4 ,dulong & ,petit discov]$ ! foll[+ law3 ,! specific heat ( an elem5t 9 ! solid =m multipli$ by its atomic weight is approximately equal to ! con/ant #f4be4 ,t is1 at4 wt4 sp4 ht4 #f4be4 ,consequ5tly1 #f4be at4 wt4 -------- sp4 ht4 ,?is law is n v accurate1 b x is (t5 possible by means ( x to decide ^u :at multiple ( ! equival5t is ! real atomic weight4 ,?us ! specific heat ( iron is f\nd by exp]im5t to be #j4aab1 & its equival5t is #bg4ie4 #f4be #j4aab #ee4h4 ,we see1 !re=e1 t ! atomic weight is twice ! equival5t1 or #ee4i4 ,h[ =mulas are det]m9$4 ,x w be well 9 connection ) molecul> weights to consid] h[ ! =mula ( a comp\nd is decid$ ^u1 = ! two subjects are v closely associat$4 ,"s examples w make cle> ! me?od foll[$4 ,! molecul> weight ( a sub/ance conta9+ hydrog5 & *lor9e 0 #cf4d4 ,by analysis #cf4d p>ts ( ! sub/ance 0 f\nd to conta9 #a "p ( hydrog5 & #ce4d p>ts ( *lor9e4 ,z ^! are ! simple atomic weights ( ! two elem5ts1 ! =mula ( ! comp\nd mu/ be ,h,cl4 ,a sub/ance consi/+ ( oxyg5 & hydrog5 0 f\nd to h a molecul> weight ( #cd4 ,analysis %[$ t 9 #cd p>ts ( ! sub/ance !re 7 #b p>ts ( hydrog5 & #cb p>ts ( oxyg54 ,divid+ ^! figures by ! atomic weights ( ! two elem5ts1 we get #b #a #b = ,h2 #cb #af #b = ,o4 ,! =mula is !re=e ,h#b,o#b4 ,a sub/ance conta9+ #b4jd ,h1 #cb4f ,s1 & #fe4c ,o 0 f\nd to h a molecul> weight ( #ih4 ,9 ^! #ih p>ts ( ! sub/ance !re are #ih #b4jd #b p>ts ( ,h1 #ih #cb4f #cb p>ts ( ,s1 & #ih #fe4c #fd p>ts ( ,o4 ,if ! molecule weighs #ih1 ! hydrog5 atoms pres5t mu/ toge!r weigh #b1 ! sulphur atoms #cb1 & ! oxyg5 atoms #fd4 ,divid+ ^! figures by ! respective atomic weights ( ! ?ree elem5ts1 we h1 = ,h1 #b #a #b atoms2 = ,s1 #cb #cb #a atom2 = ,o1 #fd #af #d atoms4 ,h5ce ! =mula is ,h#b,,s#d4 ,we h1 !n1 ?is g5]al proc$ure3 ,f9d ! p]c5tage composition ( ! sub/ance & also its molecul> weight4 ,multiply ! molecul> weight successively by ! p]c5tage ( ea* elem5t pres5t1 to f9d ! am\nt ( ! elem5t 9 ! molecul> weight ( ! comp\nd4 ,! figures s obta9$ w be ! respective p>ts ( ! molecul> weight due to ! sev]al atoms4 ,divide by ! atomic weights ( ! respective elem5ts1 & ! quoti5t w be ! numb] ( atoms pres5t4 ,avogadro's hypo!sis & *emical calculations4 ,?is law simplifies _m *emical calculations4 #a4 ,application to volume relations 9 gase\s reactions4 ,s9ce equal volumes ( gases conta9 an equal numb] ( molecules1 x foll[s t :5 an equal numb] ( gase\s molecules ( two or m gases take "p 9 a reaction1 ! reaction w involve equal volumes ( ! gases4 ,9 ! equation ,c#b;,h#b,o#d ,h#b,o ,,co#b ,,co1 s9ce #a molecule ( ea* ( ! gases ,,co#b & ,,co is set free f ea* molecule ( oxalic acid1 ! two sub/ances mu/ always be set free 9 equal volumes4 ,acetyl5e burns 9 accordance ) ! equation #b;,c#b;,h#b #e,o#b #d;,,co#b #b;,h#b,o4 ,h5ce #b volumes ( acetyl5e w react ) #e volumes ( oxyg5 to =m #d volumes ( c>bon dioxide & #b volumes ( /eam4 ,t ! volume relations may be correct a gase\s elem5t mu/ be giv5 its molecul> =mula4 ,?us oxyg5 mu/ be writt5 ,o#b & n #b,o4 #b4 ,application to weights ( gases4 ,x w be recall$ t ! molecul> weight ( a gas is det]m9$ by asc]ta9+ ! weight ( #bb4d l4 ( ! gas4 ,?is weight 9 grams is call$ ! gram-molecul> weight ( a gas4 ,if ! molecul> weight ( any gas is kn[n1 ! weight ( a lit] ( ! gas "u /&>d conditions may be det]m9$ by divid+ its gram-molecul> weight by #bb4d4 ,?us ! gram-molecul> weight ( a hydro*loric acid gas is #cf4deh4 ,a lit] ( ! gas w !re=e weigh #cf4deh #bb4d #a4fbg g4 ,,ex]cises #a4 ,f ! foll[+ data calculate ! atomic weight ( sulphur4 ,! equival5t1 z obta9$ by an analysis ( sulphur dioxide1 is #af4jc4 ,! d5sities & compositions ( a numb] ( comp\nds conta9+ sulphur are z foll[s3 ,,"n ,,d5sity ,,composition ,,by ,,p]c5tage ,hydrosulphuric acid #a4agia ,s #id4aa ,h #e4hi ,sulphur dioxide #b4bbb ,s #ej4je ,o #di4ie ,sulphur trioxide #b4gd ,s #dj4je ,o #ei4ie ,sulphur *loride #d4gj ,s #dg4dh ,cl #eb4eb ,sulphuryl *loride #d4fd ,s #bc4ge ,cl #eb4ec ,o #bc4gj ,c>bon disulphide #b4fh ,s #hd4bd ,c #ae4gf #b4 ,calculate ! =mulas = comp\nds ( ! foll[+ compositions3 ,,molecul> ,,weight 7#a7 ,s #ci4jg ,o #eh4di ,h #b4dd #ha4j 7#b7 ,ca #bi4dj ,s #bc4ef ,o #dg4jd #acf4b 7#c7 ,k #ch4fg ,n #ac4hh ,o #dg4de #aja4b #c4 ,! molecul> weight ( ammonia is #ag4jf2 ( sulphur dioxide is #fd4jf2 ( *lor9e is #gj4i4 ,f ! molecul> weight calculate ! weight ( #a l4 ( ea* ( ^! gases4 ,comp>e y\r results ) ! table on ! back cov] ( ! book4 #d4 ,f ! molecul> weight ( ! same gases calculate ! d5sity ( ea*1 ref]r$ to air z a /&>d4 #e4 ,a mixture ( #ej cc4 ( c>bon monoxide & #ej cc4 ( oxyg5 0 explod$ 9 a eudiomet]1 7a7 ,:at gases rema9$ 9 ! tube aft] ! explosion8 7b7 ,:at 0 ! volume ( ea*8 #f4 ,9 :at proportion mu/ acetyl5e & oxyg5 be mix$ to produce ! greate/ explosion8 #g4 ,solve ,problem #ah1 ,*apt] ,,xvii1 )\t us+ molecul> weights4 ,comp>e y\r results4 #h4 ,solve ,problem #aj1 ,*apt] ,,xviii1 )\t us+ molecul> weights4 ,comp>e y\r results4 #i4 ,! specific heat ( alum9ium is #j4bad2 ( lead is #j4jca4 ,f ^! specific heats calculate ! atomic weights ( ea* ( ! elem5ts4 ,,*apt] ,,xx ,,! ,,phosphorus ,,family ,,atomic ,,melt+ ,,symbol ,,weight ,,d5sity ,,po9t ---------------------------------------- ------ ,phosphorus ,p #ca4j #a4h #dc4c ,ars5ic ,z #ge4j #e4gc --- ,antimony ,sb #abj4b #f4g #dcb ,bismu? ,bi #bjh4e #i4h #bgj ,! family4 ,! elem5ts con/itut+ ?is family belong 9 ! same gr\p ) nitrog5 & !re=e resemble x 9 a g5]al way4 ,!y exhibit a regul> gradation ( physical prop]ties1 z is %[n 9 ! above table4 ,! same g5]al gradation is also f\nd 9 _! *emical prop]ties1 phosphorus be+ an acid-=m+ elem5t1 :ile bismu? is ess5tially a metal4 ,! o!r two elem5ts are int]m$iate 9 prop]ties4 ,comp\nds4 ,9 g5]al ! elem5ts ( ! family =m comp\nds hav+ simil> composition1 z is %[n 9 ! foll[+ table3 ,,ph#c ,p,cl#c ,p,cl#e ,p#b,o#c ,p#b,o#e ,as,h#c ,as,cl#c ,as,cl#e ,z#b,o#c ,z#b,o#e ,sb,h#c ,sb,cl#c ,sb,cl#e ,sb#b,o#c ,sb#b,o#e 4444 ,bi,cl#c ,bi,cl#e ,bi#b,o#c ,bi#b,o#e ,9 ! case ( phosphorus1 ars5ic1 & antimony ! oxides are acid anhydrides4 ,salts ( at lea/ f\r acids ( ea* ( ^! ?ree elem5ts are kn[n1 ! free acid 9 "s in/ances be+ un/able4 ,! relation ( ^! acids to ! correspond+ anhydrides may be illu/rat$ z foll[s1 phosphorus be+ tak5 z an example3 ,p#b,o#c #c;,h#b,o #b;,h#c,,po#c 7phosphor\s acid74 ,p#b,o#e #c;,h#b,o #b;,h#c,,po#d 7phosphoric acid74 ,p#b,o#e #b;,h#b,o ,h#d,p#b,o#g 7pyrophosphoric acid74 ,p#b,o#e ,h#b,o #b;,,hpo#c 7metaphosphoric acid74 ,,phosphorus ,hi/ory4 ,! elem5t phosphorus 0 discov]$ by ! al*emi/ ,br&1 ( ,hamburg1 9 #affi1 :ile se>*+ = ! philosoph]'s /one4 ,ow+ to its peculi> prop]ties & ! secrecy :i* 0 ma9ta9$ ab\t its prep>ation1 x rema9$ a v r>e & co/ly sub/ance until ! dem& = x 9 ! manufacture ( mat*es br\ght ab\t its production on a l>ge scale4 ,occurr5ce4 ,ow+ to its great *emical activity phosphorus nev] occurs free 9 nature4 ,9 ! =m ( phosphates x is v abundant & widely di/ribut$4 ,phosphorite & sombr]ite are m9]al =ms ( calcium phosphate1 :ile apatite consi/s ( calcium phosphate toge!r ) calcium fluoride or *loride4 ,^! m9]als =m v l>ge deposits & are ext5sively m9$ = use z f]tiliz]s4 ,calcium phosphate is a con/itu5t ( all f]tile soil1 hav+ be5 suppli$ to ! soil by ! dis9tegration ( rocks conta9+ x4 ,x is ! *ief m9]al con/itu5t ( bones ( animals1 & bone a% is !re=e ne>ly pure calcium phosphate4 ,prep>ation4 ,phosphorus is n[ manufactur$ f bone a% or a pure m9]al phosphate by heat+ ! phosphate ) s& & c>bon 9 an electric furnace4 ,! mat]ials are f$ 9 at ,m 7,fig4 #gj7 by ! fe$ screw ,f4 ,! phosphorus vapor escapes at ,p & is cond5s$ "u wat]1 :ile ! calcium silicate is tapp$ (f z a liquid at ,s4 ,! phosphorus obta9$ 9 ?is way is q impure1 & is purifi$ by di/illation4 ,illu/ration3 ,fig4 #gj ,explanation ( ! reaction4 ,to und]/& ! reaction :i* occurs1 x mu/ be rememb]$ t a volatile acid anhydride is expell$ f its salts :5 heat$ ) an anhydride :i* is n volatile4 ,?us1 :5 sodium c>bonate & silicon dioxide are heat$ toge!r ! foll[+ reaction takes place3 ,na#b;,,co#c ,si,o#b ,na#b,si,o#c ,,co#b4 ,silicon dioxide is a less volatile anhydride ?an phosphoric anhydride 7,p#b,o#e71 & :5 /rongly heat$ ) a phosphate ! phosphoric anhydride is driv5 out1 ?us3 ,ca#c7,,po#d7b #c,si,o#b #c;,ca,si,o#c ,p#b,o#e4 ,if c>bon is add$ be=e ! heat is appli$1 ! ,p#b,o#e is r$uc$ to phosphorus at ! same "t1 accord+ to ! equation ,p#b,o#e #e;,c #b,p #e;,,co4 ,physical prop]ties4 ,! purifi$ phosphorus is a pale yell[i%1 transluc5t1 waxy solid :i* melts at #dc4c & boils at #bfi4 ,x c !re=e be ca/ into any conv5i5t =m "u w>m wat]1 & is usually sold 9 ! m>ket 9 ! =m ( /icks4 ,x is q s(t & c be easily cut ) a knife1 b ?is mu/ always be done :ile ! elem5t is cov]$ ) wat]1 s9ce x is extremely inflammable1 & ! friction ( ! knife blade is almo/ sure to set x on fire if cut 9 ! air4 ,x is n soluble 9 wat]1 b is freely soluble 9 "s o!r liquids1 notably 9 c>bon disulphide4 ,its d5sity is #a4h4 ,*emical prop]ties4 ,expos$ to ! air phosphorus sl[ly comb9es ) oxyg51 & 9 s do+ emits a pale light1 or phosphoresc5ce1 :i* c be se5 only 9 a d>k place4 ,! heat ( ! room may easily raise ! temp]ature to ! k9dl+ po9t ( phosphorus1 :5 x burns ) a sputt]+ flame1 giv+ (f d5se fumes ( oxide ( phosphorus4 ,x burns ) dazzl+ brilliancy 9 oxyg51 & comb9es directly ) _m o!r elem5ts1 especially ) sulphur & ! halog5s4 ,on acc\nt ( its great aff9ity = oxyg5 x is always pres]v$ "u wat]4 ,phosphorus is v poison\s1 f #j4b to #j4c gram be+ a fatal dose4 ,gr\nd up ) fl\r & wat] or simil> sub/ances1 x is (t5 us$ z a poison = rats & o!r v]m94 ,precaution4 ,! heat ( ! body is suffici5t to raise phosphorus above its k9dl+ temp]ature1 & = ?is reason x %\ld always be h&l$ ) =ceps & nev] ) ! b>e f+]s4 ,burns occasion$ by x are v pa9ful & sl[ 9 heal+4 ,r$ phosphorus4 ,on /&+1 yell[ phosphorus gradually und]goes a rem>kable *ange1 be+ conv]t$ into a d>k r$ p[d] :i* has a d5sity ( #b4a4 ,x no long] takes fire easily1 nei!r does x dissolve 9 c>bon disulphide4 ,x is n poison\s &1 9 fact1 seems to be an entirely diff]5t sub/ance4 ,! velocity ( ?is *ange increases ) rise 9 temp]ature1 & ! r$ phosphorus is !re=e prep>$ by heat+ ! yell[ j bel[ ! boil+ po9t 7#bej-cjj74 ,:5 di/ill$ & quickly cond5s$ ! r$ =m *anges back to ! yell[4 ,?is is 9 accordance ) ! g5]al rule t :5 a sub/ance capable ( exi/+ 9 sev]al allotropic =ms is cond5s$ f a gas or cry/alliz$ f ! liquid /ate1 ! m un/able v>iety =ms fir/1 & ?is !n passes into ! m /able =ms4 ,mat*es4 ,! *ief use ( phosphorus is 9 ! manufacture ( mat*es4 ,common mat*es are made by fir/ dipp+ ! mat* /icks into "s inflammable sub/ance1 su* z melt$ p>aff91 & aft]w>d into a pa/e consi/+ ( 7#a7 phosphorus1 7#b7 "s oxidiz+ sub/ance1 su* z manganese dioxide or potassium *lorate1 & 7#c7 a b9d+ mat]ial1 usually "s k9d ( glue4 ,on friction ! phosphorus is ignit$1 ! combu/ion be+ su/a9$ by ! oxidiz+ ag5t & communicat$ to ! wood by ! burn+ p>aff94 ,9 sulphur mat*es ! p>aff9 is replac$ by sulphur4 ,9 safety mat*es r$ phosphorus1 an oxidiz+ ag5t1 & "s gritty mat]ial su* z em]y is plac$ on ! side ( ! box1 :ile ! mat* tip is provid$ z be=e ) an oxidiz+ ag5t & an easily oxidiz$ sub/ance1 usually antimony sulphide4 ,! mat* _c be ignit$ easily by friction1 save on ! prep>$ surface4 ,comp\nds ( phosphorus ) hydrog54 ,phosphorus =ms sev]al comp\nds ) hydrog51 ! be/ kn[n ( :i* is phosph9e 7,,ph#c7 analog\s to ammonia 7,,nh#c74 ,prep>ation ( phosph9e4 ,phosph9e is usually made by heat+ phosphorus ) a /rong solution ( potassium hydroxide1 ! reaction be+ a complicat$ "o4 ,illu/ration3 ,fig4 #ga ,! exp]im5t c be conv5i5tly made 9 ! app>atus %[n 9 ,fig4 #ga4 ,a /rong solution ( potassium hydroxide toge!r ) sev]al small bits ( phosphorus are plac$ 9 ! flask ,a1 & a curr5t ( coal gas is pass$ into ! flask ?r\gh ! tube ,b until all ! air has be5 displac$4 ,! gas is !n turn$ (f & ! flask is heat$4 ,phosph9e is =m$ 9 small quantities & escapes ?r\gh ! deliv]y tube1 ! exit ( :i* is j cov]$ by ! wat] 9 ! vessel ,c4 ,ea* bubble ( ! gas z x escapes into ! air takes fire1 & ! product ( combu/ion 7,p#b,o#e7 =ms beautiful small r+s1 :i* float unbrok5 = a consid]able "t 9 quiet air4 ,! pure phosph9e does n take fire spontane\sly4 ,:5 prep>$ z direct$ above1 impurities are pres5t :i* imp>t ?is prop]ty4 ,prop]ties4 ,phosph9e is a gas ( unpleasant odor & is exce$+ly poison\s4 ,l ammonia x =ms salts ) ! halog5 acids4 ,?us we h phosphonium *loride 7,,ph#d;,cl7 analog\s to ammonium *loride 7,,nh#d;,cl74 ,! phosphonium salts are ( b little importance4 ,oxides ( phosphorus4 ,phosphorus =ms two well-kn[n oxides1--! trioxide 7,p#b,o#c7 & ! p5toxide 7,p#b,o#e71 sometimes call$ phosphoric anhydride4 ,:5 phosphorus burns 9 an insuffici5t supply ( air ! product is p>tially ! trioxide2 9 oxyg5 or an excess ( air ! p5toxide is =m$4 ,! p5toxide is mu* ! bett] kn[n ( ! two4 ,x is a sn[-:ite1 volum9\s p[d] ^: mo/ m>k$ prop]ty is its great attraction = wat]4 ,x has no *emical action ^u mo/ gases1 s t !y c be v ?or\ghly dri$ by all[+ !m to pass ?r\gh prop]ly arrang$ vessels conta9+ phosphorus p5toxide4 ,acids ( phosphorus4 ,! important acids ( phosphorus are ! foll[+3 ,h#c,,po#c phosphor\s acid4 ,h#c,,po#d phosphoric acid4 ,h#d,p#b,o#g pyrophosphoric acid4 ,,hpo#c metaphosphoric acid4 ,^! may be reg>d$ z comb9ations ( ! oxides ( phosphorus ) wat] accord+ to ! equations giv5 9 ! discussion ( ! *>act]i/ics ( ! family4 #a4 ,phosphor\s acid 7,h#c,,po#c74 ,nei!r ! acid nor its salts are at all frequ5tly met ) 9 *emical op]ations4 ,x c be easily obta9$1 h[ev]1 9 ! =m ( transp>5t cry/als :5 phosphorus tri*loride is treat$ ) wat] & ! result+ solution is evaporat$3 ,p,cl#c #c;,h#b,o ,h#c,,po#c #c;,h,cl4 ,its mo/ int]e/+ prop]ty is its t5d5cy to take up oxyg5 & pass ov] into phosphoric acid4 #b4 ,or?ophosphoric acid 7phosphoric acid7 7,h#c,,po#d74 ,?is acid c be obta9$ by dissolv+ phosphorus p5toxide 9 boil+ wat]1 z repres5t$ 9 ! equation ,p#b,o#e #c;,h#b,o #b;,h#c,,po#d4 ,x is usually made by treat+ calcium phosphate ) conc5trat$ sulphuric acid4 ,! calcium sulphate produc$ 9 ! reaction is ne>ly insoluble1 & c be filt]$ (f1 leav+ ! phosphoric acid 9 solution4 ,v pure acid is made by oxidiz+ phosphorus ) nitric acid4 ,x =ms l>ge colorless cry/als :i* are exce$+ly soluble 9 wat]4 ,be+ a tribasic acid1 x =ms acid z well z normal salts4 ,?us ! foll[+ comp\nds ( sodium are kn[n3 ,na,h#b,,po#d monosodium hydrog5 phosphate4 ,na#b;,,hpo#d disodium hydrog5 phosphate4 ,na#c,,po#d normal sodium phosphate4 ,^! salts are sometimes call$ respectively prim>y1 second>y1 & t]ti>y phosphates4 ,!y may be prep>$ by br++ toge!r phosphoric acid & appropriate quantities ( sodium hydroxide4 ,phosphoric acid also =ms mix$ salts1 t is1 salts conta9+ two diff]5t metals4 ,! mo/ famili> comp\nd ( ?is k9d is microcosmic salt1 :i* has ! =mula ,na7,,nh#d7;,,hpo#d4 ,or?ophosphates4 ,! or?ophosphates =m an important class ( salts4 ,! normal salts are ne>ly all insoluble & _m ( !m occur 9 nature4 ,! second>y phosphates are z a rule insoluble1 :ile mo/ ( ! prim>y salts are soluble4 #c4 ,pyrophosphoric acid 7,h#d,p#b,o#g74 ,on heat+ or?ophosphoric acid to ab\t #bbe pyrophosphoric acid is =m$ 9 accordance ) ! foll[+ equation3 #b;,h#c,,po#d ,h#d,p#b,o#g ,h#b,o4 ,x is a :ite cry/all9e solid4 ,its salts c be prep>$ by heat+ a second>y phosphate3 #b,na#b;,,hpo#d ,na#d,p#b,o#g ,h#b,o4 #d4 ,metaphosphoric acid 7glacial phosphoric acid7 7,,hpo#c74 ,?is acid is =m$ :5 or?ophosphoric acid is heat$ above #djj3 ,h#c,,po#d ,,hpo#c ,h#b,o4 ,x is also =m$ :5 phosphorus p5toxide is treat$ ) cold wat]3 ,p#b,o#e ,h#b,o #b;,,hpo#c4 ,x is a :ite cry/all9e solid1 & is s /able t[>ds heat t x c be fus$ & ev5 volatiliz$ )\t decomposition4 ,on cool+ f ! fus$ /ate x =ms a glassy solid1 & on ?is acc\nt is (t5 call$ glacial phosphoric acid4 ,x possesses ! prop]ty ( dissolv+ small quantities ( metallic oxides1 ) ! =mation ( comp\nds :i*1 9 ! case ( c]ta9 metals1 h *>act]i/ic colors4 ,x is !re=e us$ 9 ! detection ( ^! metals4 ,:ile ! second>y phosphates1 on heat+1 give salts ( pyrophosphoric acid1 ! prim>y phosphates yield salts ( metaphosphoric acid4 ,! equations repres5t+ ^! reactions are z foll[s3 #b,na#b;,,hpo#d ,na#d,p#c,o#g ,h#b,o1 ,na,h#b,,po#d ,na,p,o#c ,h#b,o4 ,f]tiliz]s4 ,:5 crops are produc$ ye> aft] ye> on ! same field c]ta9 con/itu5ts ( ! soil ess5tial to plant gr[? are remov$1 & ! soil becomes impov]i%$ & unproductive4 ,to make ! l& once m f]tile ^! con/itu5ts mu/ be replac$4 ,! calcium phosphate ( ! m9]al deposits or ( bone a% s]ves well z a mat]ial = re/or+ phosphorus to soils exhau/$ ( t ess5tial elem5t2 b a m soluble sub/ance1 :i* ! plants c m readily assimilate1 is desirable4 ,x is bett]1 !re=e1 to conv]t ! insoluble calcium phosphate into ! soluble prim>y phosphate be=e x is appli$ z f]tiliz]4 ,x w be se5 by ref]5ce to ! =mulas = ! or?ophosphates 7see page #bdd7 t 9 a prim>y phosphate only "o hydrog5 atom ( phosphoric acid is replac$ by a metal4 ,s9ce ! calcium atom always replaces two hydrog5 atoms1 x might be ?\ght t !re c\ld be no prim>y calcium phosphate2 b if ! calcium atom replaces "o hydrog5 atom f ea* ( two molecules ( phosphoric acid1 ! salt ,ca7,h#b,,po#d7b w result1 & ?is is a prim>y phosphate4 ,x c be made by treatm5t ( ! normal phosphate ) ! necess>y am\nt ( sulphuric acid1 calcium sulphate be+ =m$ at ! same "t1 ?us3 ,ca#c7,,po#d7b #b;,h#b,,s#d ,ca7,h#b,,po#d7b #b;,ca,s,o#d4 ,! result+ mixture is a p[d]1 :i* is sold z a f]tiliz] "u ! "n ( sup]phosphate ( lime4 ,,ars5ic ,occurr5ce4 ,ars5ic occurs 9 consid]able quantities 9 nature z ! native elem5t1 z ! sulphides realg> 7,z#b,s#b7 & orpim5t 7,z#b,s#c71 z oxide 7,z#b,o#c71 & z a con/itu5t ( _m metallic sulphides1 su* z ars5opyrite 7,fe,as,s74 ,prep>ation4 ,! elem5t is prep>$ by purify+ ! native ars5ic1 or by heat+ ! ars5opyrite 9 iron tubes1 out ( contact ) air1 :5 ! reaction express$ by ! foll[+ equation occurs3 ,fe,as,s ,fe,s ,z4 ,! ars5ic1 be+ volatile1 cond5ses 9 *amb]s connect$ ) ! heat$ tubes4 ,x is also made f ! oxide by r$uction ) c>bon3 #b;,z#b,o#c #c;,c #d;,z #c;,,co#b4 ,prop]ties4 ,ars5ic is a /eel-gray1 metallic-look+ sub/ance ( d5sity #e4gc4 ,?\gh resembl+ metals 9 appe>ance1 x is q brittle1 be+ easily p[d]$ 9 a mort>4 ,:5 /rongly heat$ x sublimes1 t is1 x passes into a vapor )\t melt+1 & cond5ses aga9 to a cry/all9e solid :5 ! vapor is cool$4 ,l phosphorus x c be obta9$ 9 sev]al allotropic =ms4 ,x alloys readily ) "s ( ! metals1 & f9ds its *ief use z an alloy ) lead1 :i* is us$ = mak+ %ot1 ! alloy be+ h>d] ?an pure lead4 ,:5 heat$ on *>coal ) ! bl[pipe x is conv]t$ into an oxide :i* volatilizes1 leav+ ! *>coal un/a9$ by any oxide coat+4 ,x burns readily 9 *lor9e gas1 =m+ ars5ic tri*loride1-- ,z #c;,cl ,as,cl#c4 ,unlike mo/ ( its comp\nds1 ! elem5t itself is n poison\s4 ,ars9e 7,as,h#c74 ,:5 any comp\nd conta9+ ars5ic is br\ght into ! pres5ce ( nasc5t hydrog51 ars9e 7,as,h#c71 correspond+ to phosph9e & ammonia1 is =m$4 ,! reaction :5 oxide ( ars5ic is s treat$ is ,z#b,o#c #ab;,h #b;,as,h#c #c;,h#b,o4 ,ars9e is a gas ) a peculi> g>lic-l odor1 & is int5sely poison\s4 ,a s+le bubble ( pure gas has be5 kn[n to prove fatal4 ,x is an un/able comp\nd1 decompos+ into its elem5ts :5 heat$ to a mod]ate temp]ature4 ,x is combu/ible1 burn+ ) a pale blui%-:ite flame to =m ars5ic trioxide & wat] :5 air is 9 excess3 #b;,as,h#c #f,o ,z#b,o#c #c;,h#b,o4 ,:5 ! supply ( air is defici5t wat] & metallic ars5ic are =m$3 #b;,as,h#c #c,o #c;,h#b,o #b;,z4 ,^! reactions make ! detection ( ev5 m9ute quantities ( ars5ic a v easy problem4 ,illu/ration3 ,fig4 #gb ,m>%'s te/ = ars5ic4 ,! me?od devis$ by ,m>% = detect+ ars5ic is mo/ frequ5tly us$1 ! app>atus be+ %[n 9 ,fig4 #gb4 ,hydrog5 is g5]at$ 9 ! flask ,a by ! action ( dilute sulphuric acid on z9c1 is dri$ by pass+ ov] calcium *loride 9 ! tube ,b1 & aft] pass+ ?r\gh ! h>d-glass tube ,c is ignit$ at ! jet ,d4 ,if a sub/ance conta9+ ars5ic is n[ introduc$ into ! g5]ator ,a1 ! ars5ic is conv]t$ into ars9e by ! action ( ! nasc5t hydrog51 & passes to ! jet along ) ! hydrog54 ,if ! tube ,c is /rongly heat$ at "s po9t ne> ! middle1 ! ars9e is decompos$ :ile pass+ ?is po9t & ! ars5ic is deposit$ j beyond ! heat$ po9t 9 ! =m ( a %9+1 br[ni%-black mirror4 ,if ! tube is n heat$1 ! ars9e burns along ) ! hydrog5 at ! jet4 ,"u ^! conditions a small porcela9 di% cr[d$ d[n into ! flame is black5$ by a spot ( metallic ars5ic1 = ! ars9e is decompos$ by ! heat ( ! flame1 & ! ars5ic1 cool$ bel[ its k9dl+ temp]ature by ! cold porcela91 deposits ^u x z a black spot4 ,antimony conducts itself 9 ! same way z ars5ic1 b ! antimony deposit is m sooty 9 appe>ance4 ,! two c also be di/+ui%$ by ! fact t sodium hypo*lorite 7,na,cl,o7 dissolves ! ars5ic deposit1 b n t =m$ by antimony4 ,oxides ( ars5ic4 ,ars5ic =ms two oxides1 ,z#b,o#c & ,z#b,o#e1 correspond+ to ^? ( phosphorus4 ,( ^! ars5i\s oxide1 or ars5ic trioxide 7,z#b,o#c71 is mu* bett] kn[n1 & is ! sub/ance usually call$ :ite ars5ic1 or m]ely ars5ic4 ,x is f\nd z a m9]al1 b is usually obta9$ z a by-product 9 burn+ pyrite 9 ! sulphuric-acid indu/ry4 ,! pyrite has a small am\nt ( ars5opyrite 9 x1 & :5 ?is is burn$ ars5i\s oxide is =m$ z a vapor toge!r ) sulphur dioxide3 #b;,fe,as,s #aj,o ,fe#b,o#c ,z#b,o#c #b,,s#b4 ,! ars5i\s oxide is cond5s$ 9 appropriate *amb]s4 ,x is a r heavy sub/ance1 obta9$ ei!r z a cry/all9e p[d] or z l>ge1 vitre\s lumps1 resembl+ lumps ( porcela9 9 appe>ance4 ,x is v poison\s1 f #j4b to #j4c g4 be+ a fatal dose4 ,x is frequ5tly giv5 z a poison1 s9ce x is ne>ly ta/eless & does n act v rapidly4 ,?is sl[ action is due to ! fact t x is n v soluble1 & h5ce is absorb$ sl[ly by ! sy/em4 ,ars5i\s oxide is also us$ z a *emical reag5t 9 glass mak+ & 9 ! dye indu/ry4 ,acids ( ars5ic4 ,l ! correspond+ oxides ( phosphorus1 ! oxides ( ars5ic are acid anhydrides4 ,9 solution !y comb9e ) bases to =m salts1 correspond+ to ! salts ( ! acids ( phosphorus4 ,?us we h salts ( ! foll[+ acids3 ,h#c;,as,o#c ars5i\s acid4 ,h#c;,as,o#d or?o>s5ic acid4 ,h#d;,z#b,o#c pyro>s5ic acid4 ,h,as,o#c met>s5ic acid4 ,sev]al o!r acids ( ars5ic are also kn[n4 ,n all ( ^! c be obta9$ z free acids1 s9ce !y t5d to lose wat] & =m ! oxides4 ,?us1 in/ead ( obta9+ ars5i\s acid 7,h#c;,as,o#c71 ! oxide ,z#b,o#c is obta9$3 #b;,h#c;,as,o#c ,z#b,o#c #c;,h#b,o4 ,salts ( all ! acids are kn[n1 h[ev]1 & "s ( !m h comm]cial value4 ,mo/ ( !m are insoluble1 & "s ( ! copp] salts1 :i* are gre51 are us$ z pigm5ts4 ,p>is gre51 :i* has a complicat$ =mula1 is a well-kn[n insecticide4 ,antidote = ars5ical poison+4 ,! mo/ effici5t antidote = ars5ic poison+ is f]ric hydroxide4 ,x is prep>$ z ne$$1 accord+ to ! equation ,fe#b7,,s#d7c #c,mg7,,oh7#b #b;,fe7,,oh7#c #c,mg,s,o#d4 ,sulphides ( ars5ic4 ,:5 hydrog5 sulphide is pass$ into an acidifi$ solution conta9+ an ars5ic comp\nd ! ars5ic is precipitat$ z a bright yell[ sulphide1 ?us3 #b;,h#c;,as,o#c #c;,h#b,s ,z#b,s#c #f;,h#b,o1 #b;,h#c;,as,o#d #e;,h#b,s ,z#b,s#e #h;,h#b,o4 ,9 ?is respect ars5ic resembles ! metallic elem5ts1 _m ( :i* produce sulphides "u simil> conditions4 ,! sulphides ( ars5ic1 bo? ^? produc$ artificially & ^? f\nd 9 nature1 are us$ z yell[ pigm5ts4 ,,antimony ,occurr5ce4 ,antimony occurs 9 nature *iefly z ! sulphide 7,sb#b,s#c71 call$ /ibnite1 ?\gh x is also f\nd z oxide & z a con/itu5t ( _m complex m9]als4 ,prep>ation4 ,antimony is prep>$ f ! sulphide 9 a v simple mann]4 ,! sulphide is melt$ ) scrap iron 9 a furnace1 :5 ! iron comb9es ) ! sulphur to =m a slag1 or liquid lay] ( melt$ iron sulphide1 :ile ! heavi] liquid1 antimony1 settles to ! bottom & is drawn (f f "t to "t4 ,! reaction involv$ is repres5t$ by ! equation ,sb#b,s#c #c;,fe #b,sb #c;,fe,s4 ,physical prop]ties4 ,antimony is a blui%-:ite1 metallic-look+ sub/ance ^: d5sity is #f4g4 ,x is highly cry/all9e1 h>d1 & v brittle4 ,x has a r l[ melt+ po9t 7#dcb7 & exp&s v noticeably on solidify+4 ,*emical prop]ties4 ,9 *emical prop]ties antimony resembles ars5ic 9 _m p>ticul>s4 ,x =ms ! oxides ,sb#b,o#c & ,sb#b,o#e1 & 9 addition ,sb#b,o#d4 ,x comb9es ) ! halog5 elem5ts ) great en]gy1 burn+ brilliantly 9 *lor9e to =m antimony tri*loride 7,sb,cl#c74 ,:5 heat$ on *>coal ) ! bl[pipe x is oxidiz$ & =ms a coat+ ( antimony oxide on ! *>coal :i* has a *>act]i/ic blui%-:ite color4 ,/ib9e 7,sb,h#c74 ,! gas /ib9e 7,sb,h#c7 is =m$ "u conditions :i* are v simil> to ^? :i* produce ars9e1 & x closely resembles ! latt] comp\nd1 ?\gh x is /ill less /able4 ,x is v poison\s4 ,acids ( antimony4 ,! oxides ,sb#b,o#c & ,sb#b,o#e are weak acid anhydrides & are capable ( =m+ two s]ies ( acids correspond+ 9 =mulas to ! acids ( phosphorus & ars5ic4 ,!y are mu* weak]1 h[ev]1 & are ( little practical importance4 ,sulphides ( antimony4 ,antimony resembles ars5ic 9 t hydrog5 sulphide precipitates x z a sulphide :5 conduct$ into an acidifi$ solution conta9+ an antimony comp\nd3 #b,sb,cl#c #c;,h#b,s ,sb#b,s#c #f;,h,cl1 #b,sb,cl#e #e;,h#b,s ,sb#b,s#e #aj;,h,cl4 ,! two sulphides ( antimony are call$ ! trisulphide & ! p5tasulphide respectively4 ,:5 prep>$ 9 ?is way !y are orange-color$ sub/ances1 ?\gh ! m9]al /ibnite is black4 ,metallic prop]ties ( antimony4 ,! physical prop]ties ( ! elem5t are ^? ( a metal1 & ! fact t its sulphide is precipitat$ by hydrog5 sulphide %[s t x acts l a metal 9 a *emical way4 ,_m o!r reactions %[ t antimony has m ( ! prop]ties ( a metal ?an ( a non-metal4 ,! comp\nd ,sb7,,oh7#c1 correspond+ to ars5i\s acid1 :ile able to act z a weak acid is also able to act z a weak base ) /rong acids4 ,= example1 :5 treat$ ) conc5trat$ hydro*loric acid antimony *loride is =m$3 ,sb7,,oh7#c #c;,h,cl ,sb,cl#c #c;,h#b,o4 ,a numb] ( elem5ts act 9 ?is same way1 _! hydroxides "u "s conditions be+ weak acids & "u o!rs weak bases4 ,,alloys ,"s metals :5 melt$ toge!r ?or\ghly int]mix1 & on cool+ =m a homog5e\s1 metallic-appe>+ sub/ance call$ an alloy4 ,n all metals w mix 9 ?is way1 & 9 "s cases def9ite *emical comp\nds are =m$ & sep>ate out z ! mixture solidifies1 ?us de/roy+ ! uni=m quality ( ! alloy4 ,9 g5]al ! melt+ po9t ( ! alloy is bel[ ! av]age ( ! melt+ po9ts ( its con/itu5ts1 & x is (t5 l[] ?an any "o ( !m4 ,antimony =ms alloys ) _m ( ! metals1 & its *ief comm]cial use is = su* purposes4 ,x imp>ts to its alloys high d5sity1 r l[ melt+ po9t1 & ! prop]ty ( exp&+ on solidification4 ,su* an alloy is especially useful 9 type f\nd+1 :]e f9e l9es are to be reproduc$ on a ca/4 ,type metal consi/s ( antimony1 lead1 & t94 ,babbitt metal1 us$ = j\rnal be>+s 9 ma*9]y1 conta9s ! same metals 9 a diff]5t proportion toge!r ) a small p]c5tage ( copp]4 ,,bismu? ,occurr5ce4 ,bismu? is usually f\nd 9 ! uncomb9$ =m 9 nature4 ,x also occurs z oxide & sulphide4 ,mo/ ( ! bismu? ( comm]ce comes f ,saxony1 & f ,mexico & ,colorado1 b x is n an abundant elem5t4 ,prep>ation4 ,x is prep>$ by m]ely heat+ ! ore conta9+ ! native bismu? & all[+ ! melt$ metal to run out into suitable vessels4 ,o!r ores are conv]t$ into oxides & r$uc$ by heat+ ) c>bon4 ,physical prop]ties4 ,bismu? is a heavy1 cry/all9e1 brittle metal ne>ly ! color ( silv]1 b ) a slightly rosy t9t :i* di/+ui%es x f o!r metals4 ,x melts at a l[ temp]ature 7#bgj7 & has a d5sity ( #i4h4 ,x is n act$ ^u by ! air at ord9>y temp]atures4 ,*emical prop]ties4 ,:5 heat$ ) ! bl[pipe on *>coal1 bismu? gives a coat+ ( ! oxide ,bi#b,o#c4 ,?is has a yell[i%-br[n color :i* easily di/+ui%es x f ! oxides =m$ by o!r metals4 ,x comb9es v readily ) ! halog5 elem5ts1 p[d]$ bismu? burn+ readily 9 *lor9e4 ,x is n v easily act$ ^u by hydro*loric acid1 b nitric & sulphuric acids act ^u x 9 ! same way t !y d ^u copp]4 ,uses4 ,bismu? f9ds its *ief use z a con/itu5t ( alloys1 p>ticul>ly 9 ^? ( l[ melt+ po9t4 ,"s ( ^! melt 9 hot wat]4 ,= example1 ,wood's metal1 consi/+ ( bismu?1 lead1 t91 & cadmium1 melts at #fj4e4 ,comp\nds ( bismu?4 ,unlike ! o!r elem5ts ( ?is gr\p1 bismu? has almo/ no acid prop]ties4 ,its *ief oxide1 ,bi#b,o#c1 is basic 9 its prop]ties4 ,x dissolves 9 /rong acids & =ms salts ( bismu?3 ,bi#b,o#c #f;,h,cl #b;,bi,cl#c #c;,h#b,o1 ,bi#b,o#c #f;,,hno#c #b;,bi7,,no#c7c #c;,h#b,o4 ,! nitrate & *loride ( bismu? c be obta9$ z well-=m$ colorless cry/als4 ,:5 treat$ ) wat] ! salts are decompos$ 9 ! mann] expla9$ 9 ! foll[+ p>agraph4 ,,hydrolysis ,_m salts su* z ^? ( antimony & bismu? =m solutions :i* are some:at acid 9 reaction1 & mu/ !re=e conta9 hydrog5 ions4 ,?is is acc\nt$ = by ! same pr9ciple sugge/$ to expla9 ! fact t solutions ( potassium cyanide are alkal9e 9 reaction 7p4 #baj74 ,wat] =ms an appreciable numb] ( hydrog5 & hydroxyl ions1 & v weak bases su* z bismu? hydroxide are dissociat$ to b a v slight ext5t4 ,:5 ,bi ions f bismu? *loride1 :i* dissociates v readily1 are br\ght 9 contact ) ! ,,oh- ions f wat]1 ! two come to ! equilibrium express$ 9 ! equation ,bi #c,,oh- -- ,bi7,,oh7#c4 ,= e hydroxyl ion remov$ f ! solution 9 ?is way a hydrog5 ion is left free1 & ! solution becomes acid 9 reaction4 ,reactions ( ?is k9d & t describ$ "u potassium cyanide are call$ hydrolysis4 ,,def9ition3 ,hydrolysis is ! action ( wat] ^u a salt to =m an acid & a base1 "o ( :i* is v slightly dissociat$4 ,conditions favor+ hydrolysis4 ,:ile hydrolysis is prim>ily due to ! slight ext5t to :i* ei!r ! acid or ! base =m$ is dissociat$1 sev]al o!r factors h an influ5ce ^u ! ext5t to :i* x w take place4 #a4 ,influ5ce ( mass4 ,s9ce hydrolysis is a rev]sible reaction1 ! relative masses ( ! react+ sub/ances influ5ce ! po9t at :i* equilibrium w be rea*$4 ,9 ! equilibrium ,bi,cl#c #c;,h#b,o -- ,bi7,,oh7#c #c;,h,cl ! addition ( m wat] w result 9 ! =mation ( m bismu? hydroxide & hydro*loric acid4 ,! addition ( m hydro*loric acid w conv]t "s ( ! bismu? hydroxide into bismu? *loride4 #b4 ,=mation ( insoluble sub/ances4 ,:5 "o ( ! products ( hydrolysis is ne>ly insoluble 9 wat] ! solution w become saturat$ ) x z soon z a v little has be5 =m$4 ,all 9 excess ( ?is w precipitate1 & ! reaction w g on until ! acid set free increases suffici5tly to br+ ab\t an equilibrium4 ,?us a consid]able am\nt ( bismu? & antimony hydroxides are precipitat$ :5 wat] is add$ to ! *lorides ( ^! elem5ts4 ,! great] ! dilution ! m hydroxide precipitates4 ,! addition ( hydro*loric acid 9 consid]able quantity w1 h[ev]1 r$issolve ! precipitate4 ,p>tial hydrolysis4 ,9 _m cases ! hydrolysis ( a salt is only p>tial1 result+ 9 ! =mation ( basic salts in/ead ( ! free base4 ,mo/ ( ^! basic salts are insoluble 9 wat]1 :i* acc\nts = _! ready =mation4 ,?us bismu? *loride may hydrolyze by successive /eps1 z %[n 9 ! equations ,bi,cl#c ,h#b,o ,bi7,,oh7,cl#b ,h,cl1 ,bi,cl#c #b;,h#b,o ,bi7,,oh7#b;,cl #b;,h,cl1 ,bi,cl#c #c;,h#b,o ,bi7,,oh7#c #c;,h,cl4 ,! basic salt s =m$ may also lose wat]1 z %[n 9 ! equation ,bi7,,oh7#b;,cl ,bi,o,cl ,h#b,o4 ,! salt repres5t$ 9 ! la/ equation is sometimes call$ bismu? oxy*loride1 or bismu?yl *loride4 ,! correspond+ nitrate1 ,bi,o,n,o#c1 is l>gely us$ 9 m$ic9e "u ! "n ( subnitrate ( bismu?4 ,9 ^! two comp\nds ! gr\p ( atoms1 ,bi,o1 acts z a unival5t metallic radical & is call$ bismu?yl4 ,simil> basic salts are =m$ by ! hydrolysis ( antimony salts4 ,,ex]cises #a4 ,"n all ! elem5ts s f> /udi$ :i* possess allotropic =ms4 #b4 ,:at comp\nds w\ld y expect phosphorus to =m ) brom9e & iod9e8 ,write ! equations %[+ ! action ( wat] on ^! comp\nds4 #c4 ,9 ! prep>ation ( phosph9e1 :y is coal gas pass$ into ! flask8 ,:at o!r gases w\ld s]ve ! same purpose8 #d4 ,give ! =mula = ! salt :i* phosph9e =ms ) hydriodic acid4 ,give ! "n ( ! comp\nd4 #e4 ,c\ld phosphoric acid be sub/itut$ = sulphuric acid 9 ! prep>ation ( ! common acids8 #f4 ,write ! equations = ! prep>ation ( ! ?ree sodium salts ( or?ophosphoric acid4 #g4 ,:y does a solution ( disodium hydrog5 phosphate react alkal9e8 #h4 ,on ! supposition t bone a% is pure calcium phosphate1 :at weight ( x w\ld be requir$ 9 ! prep>ation ( #a kg4 ( phosphorus8 #i4 ,if ars5opyrite is heat$ 9 a curr5t ( air1 :at products are =m$8 #aj4 7a7 ,write equations = ! complete combu/ion ( hydrosulphuric acid1 me?ane1 & ars9e4 7b7 ,9 :at respects are ! reactions simil>8 #aa4 ,write ! equations = all ! reactions involv$ 9 ,m>%'s te/ = ars5ic4 #ab4 ,write ! names & =mulas = ! acids ( antimony4 #ac4 ,write ! equations %[+ ! hydrolysis ( antimony tri*loride2 ( bismu? nitrate4 #ad4 ,9 :at respects does nitrog5 resemble ! memb]s ( ! phosphorus family8 ,,*apt] ,,xxi ,,silicon1 ,,titanium1 ,,boron ,,symbol ,,atomic ,,d5sity ,,*lorides ,,oxides ,,weight ,silicon ,si #bh4d #b4ce ,si,cl#d ,si,o#b ,titanium ,ti #dh4a #c4e ,ti,cl#d ,ti,o#b ,boron ,b #aa4j #b4de ,b,cl#c ,b#b,o#c ,g5]al4 ,ea* ( ! ?ree elem5ts1 silicon1 titanium1 & boron1 belongs to a sep>ate p]iodic family1 b !y occur ne> toge!r 9 ! p]iodic gr\p+ & are v simil> 9 bo? physical & *emical prop]ties4 ,s9ce ! o!r elem5ts 9 _! families are ei!r s r>e t !y _c be /udi$ 9 detail1 or are be/ und]/ood 9 connection ) o!r elem5ts1 x is conv5i5t to consid] ^! ?ree toge!r at ?is po9t4 ,! ?ree elem5ts are v difficult to obta9 9 ! free /ate1 ow+ to _! /rong attraction = o!r elem5ts4 ,!y c be prep>$ by ! action ( alum9ium or magnesium on _! oxides & 9 impure /ate by r$uction ) c>bon 9 an electric furnace4 ,!y are v h>d & melt only at ! highe/ temp]atures4 ,at ord9>y temp]atures !y are n attack$ by oxyg51 b :5 /rongly heat$ !y burn ) great brilliancy4 ,silicon & boron are n attack$ by acids "u ord9>y conditions2 titanium is easily dissolv$ by !m4 ,,silicon ,occurr5ce4 ,next to oxyg5 silicon is ! mo/ abundant elem5t4 ,x does n occur free 9 nature1 b its comp\nds are v abundant & ( ! greate/ importance4 ,x occurs almo/ entirely 9 comb9ation ) oxyg5 z silicon dioxide 7,si,o#b71 (t5 call$ silica1 or ) oxyg5 & v>i\s metals 9 ! =m ( salts ( silicic acids1 or silicates4 ,^! comp\nds =m a l>ge fraction ( ! e>?'s cru/4 ,mo/ plants absorb small am\nts ( silica f ! soil1 & x is also f\nd 9 m9ute quantities 9 animal organisms4 ,prep>ation4 ,! elem5t is mo/ easily prep>$ by r$uc+ pure p[d]$ qu>tz ) magnesium p[d]3 ,si,o#b #b,mg #b,mg,o ,si4 ,prop]ties4 ,z w\ld be expect$ f its place 9 ! p]iodic table1 silicon resembles c>bon 9 _m respects4 ,x c be obta9$ 9 sev]al allotropic =ms1 correspond+ to ^? ( c>bon4 ,! cry/alliz$ =m is v h>d1 & is inactive t[>d reag5ts4 ,! amorph\s v>iety has1 9 g5]al1 prop]ties m simil> to *>coal4 ,comp\nds ( silicon ) hydrog5 & ! halog5s4 ,silicon hydride 7,si,h#d7 corresponds 9 =mula to me?ane 7,,*#d71 b its prop]ties are m l ^? ( phosph9e 7,,ph#c74 ,x is a v inflammable gas ( disagreeable odor1 &1 z ord9>ily prep>$1 takes fire spontane\sly on acc\nt ( ! pres5ce ( impurities4 ,silicon comb9es ) ! elem5ts ( ! *lor9e family to =m su* comp\nds z ,si,cl#d & ,si,f#d4 ,( ^! silicon fluoride is ! mo/ famili> & int]e/+4 ,z /at$ 9 ! discussion ( fluor9e1 x is =m$ :5 hydr(luoric acid acts ^u silicon dioxide or a silicate4 ,) silica ! reaction is ?us express$3 ,si,o#b #d;,,hf ,si,f#d #b;,h#b,o4 ,x is a v volatile1 invisible1 poison\s gas4 ,9 contact ) wat] x is p>tially decompos$1 z %[n 9 ! equation ,si,f#d #d;,h#b,o #d;,,hf ,si7,,oh7#d4 ,! hydr(luoric acid s =m$ comb9es ) an additional am\nt ( silicon fluoride1 =m+ ! complex fluosilicic acid 7,h#b,si,f#f71 ?us3 #b;,,hf ,si,f#d ,h#b,si,f#f4 ,silicides4 ,z ! "n indicates1 silicides are b9>y comp\nds consi/+ ( silicon & "s o!r elem5t4 ,!y are v /able at high temp]atures1 & are usually made by heat+ ! appropriate sub/ances 9 an electric furnace4 ,! mo/ important "o is c>borundum1 :i* is a silicide ( c>bon ( ! =mula ,c,si4 ,x is made by heat+ coke & s&1 :i* is a =m ( silicon dioxide1 9 an electric furnace1 ! process be+ ext5sively c>ri$ on at ,niag>a ,falls4 ,! foll[+ equation repres5ts ! reaction ,si,o#b #c;,c ,c,si #b;,,co4 ,! sub/ance s prep>$ consi/s ( beautiful purpli%-black cry/als1 :i* are v h>d4 ,c>borundum is us$ z an abrasive1 t is1 z a mat]ial = gr9d+ & poli%+ v h>d sub/ances4 ,f]rosilicon is a silicide ( iron alloy$ ) an excess ( iron1 :i* f9ds ext5sive use 9 ! manufacture ( c]ta9 k9ds ( /eel4 ,manufacture ( c>borundum4 ,! mixture ( mat]ials is heat$ 9 a l>ge resi/ance furnace = ab\t ?irty-six h\rs4 ,aft] ! reaction is complet$ !re is left a core ( graphite ,g4 ,surr\nd+ ?is core is a lay] ( cry/alliz$ c>borundum ,c1 ab\t #af 94 ?ick4 ,outside ?is is a %ell ( amorph\s c>borundum ,a4 ,! rema9+ mat]ials ,m are un*ang$ & are us$ = a new *>ge4 ,illu/ration3 ,fig4 #gc ,silicon dioxide 7silica7 7,si,o#b74 ,?is sub/ance is f\nd 9 a great v>iety ( =ms 9 nature1 bo? 9 ! amorph\s & 9 ! cry/all9e condition4 ,9 ! =m ( qu>tz x is f\nd 9 beautifully =m$ six-sid$ prisms1 sometimes ( great size4 ,:5 pure x is p]fectly transp>5t & colorless4 ,"s color$ v>ieties are giv5 special names1 z ame?y/ 7violet71 rose qu>tz 7pale p9k71 smoky or milky qu>tz 7color$ & opaque74 ,o!r v>ieties ( silicon dioxide1 "s ( :i* also conta9 wat]1 are *alc$ony1 onyx1 jasp]1 opal1 agate1 & fl9t4 ,s& & s&/one are l>gely silicon dioxide4 ,prop]ties4 ,z obta9$ by *emical processes silicon dioxide is an amorph\s :ite p[d]4 ,9 ! cry/alliz$ /ate x is v h>d & has a d5sity ( #b4f4 ,x is insoluble 9 wat] & 9 mo/ *emical reag5ts1 & requires ! hotte/ oxyhydrog5 flame = fusion4 ,acids1 except+ hydr(luoric acid1 h little action on x1 & x requires ! mo/ en]getic r$uc+ ag5ts to deprive x ( oxyg54 ,x is ! anhydride ( an acid1 & consequ5tly x dissolves 9 fus$ alkalis to =m silicates4 ,be+ nonvolatile1 x w drive out mo/ o!r anhydrides :5 heat$ to a high temp]ature ) _! salts1 especially :5 ! silicates s =m$ are fusible4 ,! foll[+ equations illu/rate ?is prop]ty3 ,na#b;,,co#c ,si,o#b ,na#b,si,o#c ,,co#b1 ,na#b,,s#d ,si,o#b ,na#b,si,o#c ,,s#c4 ,silicic acids4 ,silicon =ms two simple acids1 or?osilicic acid 7,h#d,si,o#d7 & metasilicic acid 7,h#b,si,o#c74 ,or?osilicic acid is =m$ z a jelly-l mass :5 or?osilicates are treat$ ) /rong acids su* z hydro*loric4 ,on attempt+ to dry ?is acid x loses wat]1 pass+ into metasilicic or common silicic acid3 ,h#d,si,o#d ,h#b,si,o#c ,h#b,o4 ,metasilicic acid :5 heat$ breaks up into silica & wat]1 ?us3 ,h#b,si,o#c ,h#b,o ,si,o#b4 ,salts ( silicic acids1--silicates4 ,a numb] ( salts ( ! or?osilicic & metasilicic acids occur 9 nature4 ,?us mica 7,k,al,si,o#d7 is a salt ( or?osilicic acid4 ,polysilicic acids4 ,silicon has ! p[] to =m a great _m complex acids :i* may be reg>d$ z d]iv$ f ! union ( sev]al molecules ( ! or?osilicic acid1 ) ! loss ( wat]4 ,?us we h #c;,h#d,si,o#d ,h#d,si#c,o#h #d;,h#b,o4 ,^! acids _c be prep>$ 9 ! pure /ate1 b _! salts =m _m ( ! cry/all9e rocks 9 nature4 ,feldsp>1 = example1 has ! =mula ,k,al,si#c,o#h1 & is a mix$ salt ( ! acid ,h#d,si#c,o#h1 ^: =mation is repres5t$ 9 ! equation above4 ,kaol9 has ! =mula ,al#b,si#b,o#gb;,h#b,o4 ,_m o!r examples w be met 9 ! /udy ( ! metals4 ,glass4 ,:5 sodium & calcium silicates1 toge!r ) silicon dioxide1 are heat$ to a v high temp]ature1 ! mixture sl[ly fuses to a transp>5t liquid1 :i* on cool+ passes into ! solid call$ glass4 ,in/ead ( />t+ ) sodium & calcium silicates x is m conv5i5t & economical to heat sodium c>bonate 7or sulphate7 & lime ) an excess ( clean s&1 ! silicates be+ =m$ dur+ ! heat+3 ,na#b;,,co#c ,si,o#b ,na#b,si,o#c ,,co#b1 ,ca,o ,si,o#b ,ca,si,o#c4 ,illu/ration3 ,fig4 #gd ,! mixture is heat$ bel[ ! fus+ po9t = "s "t1 s t ! escap+ c>bon dioxide may n spatt] ! hot liquid2 ! heat is !n increas$ & ! mixture kept 9 a /ate ( fusion until all gases =m$ 9 ! reaction h escap$4 ,mold+ & bl[+ ( glass4 ,! way 9 :i* ! melt$ mixture is h&l$ 9 ! glass factory dep5ds ^u ! "* ( ! article to be made4 ,_m articles1 su* z bottles1 are made by bl[+ ! pla/ic glass into holl[ molds ( ! desir$ %ape4 ,! mold is fir/ op5$1 z %[n 9 ,fig4 #gd4 ,a lump ( pla/ic glass ,a on ! holl[ rod ,b is l[]$ into ! mold1 :i* is !n clos$ by ! h&les ,c4 ,by bl[+ into ! tube ! glass is bl[n into ! %ape ( ! mold4 ,! mold is !n op5$ & ! bottle lift$ out4 ,! neck ( ! bottle mu/ be cut (f at ! prop] place & ! %>p edges r\nd$ (f 9 a flame4 ,o!r objects1 su* z lamp *imneys1 are made by gett+ a lump ( pla/ic glass on ! end ( a holl[ iron rod & bl[+ x into ! desir$ %ape )\t ! help ( a mold1 great skill be+ requir$ 9 ! manipulation ( ! glass4 ,w9d[ glass is made by bl[+ l>ge holl[ cyl9d]s ab\t #f ft4 long & #a-a_/b ft4 9 diamet]4 ,^! are cut longitud9ally1 & are !n plac$ 9 an ov5 & heat$ until !y s(t51 :5 !y are flatt5$ out into plates 7,fig4 #ge74 ,plate glass is ca/ into flat slabs1 :i* are !n gr\nd & poli%$ to p]fectly plane surfaces4 ,v>ieties ( glass4 ,! +r$i5ts m5tion$ above make a s(t1 easily fusible glass4 ,if potassium c>bonate is sub/itut$ = ! sodium c>bonate1 ! glass is mu* h>d] & less easily fus$2 increas+ ! am\nt ( s& has some:at ! same effect4 ,potassium glass is l>gely us$ 9 mak+ *emical glassw>e1 s9ce x resi/s ! action ( reag5ts bett] ?an ! s(t] sodium glass4 ,if lead oxide is sub/itut$ = ! :ole or a "p ( ! lime1 ! glass is v s(t1 b has a high index ( refraction & is valuable = mak+ optical in/rum5ts & artificial jewels4 ,illu/ration3 ,fig4 #ge ,color+ ( glass4 ,v>i\s sub/ances fus$ along ) ! glass mixture give *>act]i/ic colors4 ,! amb] color ( common bottles is due to iron comp\nds 9 ! glass2 9 o!r cases iron colors ! glass gre54 ,cobalt comp\nds color x deep blue2 ^? ( manganese give x an ame?y/ t9t & uranium comp\nds imp>t a peculi> yell[i% gre5 color4 ,s9ce iron is ne>ly always pres5t 9 ! +r$i5ts1 glass is usually slightly yell[4 ,?is color c be remov$ by add+ ! prop] am\nt ( manganese dioxide1 = ! ame?y/ color ( manganese & ! yell[ ( iron toge!r produce :ite light4 ,nature ( glass4 ,glass is n a def9ite *emical comp\nd & its composition v>ies betwe5 wide limits4 ,fus$ glass is really a solution ( v>i\s silicates1 su* z ^? ( calcium & lead1 9 fus$ sodium or potassium silicate4 ,a c]ta9 am\nt ( silicon dioxide is also pres5t4 ,?is solution is !n all[$ to solidify "u su* conditions ( cool+ t ! dissolv$ sub/ances d n sep>ate f ! solv5t4 ,! comp\nds :i* are us$ to color ! glass are sometimes conv]t$ into silicates1 :i* !n dissolve 9 ! glass1 giv+ x a uni=m color4 ,9 o!r cases1 z 9 ! milky glasses :i* resemble porcela9 9 appe>ance1 ! color or opaqu5ess is due to ! f9ely divid$ color mat]ial ev5ly di/ribut$ ?r\gh\t ! glass1 b n dissolv$ 9 x4 ,milky glass is made by mix+ calcium fluoride1 t9 oxide1 or "s o!r insoluble sub/ance 9 ! melt$ glass4 ,copp] or gold 9 metallic =m scatt]$ ?r\gh glass gives x %ades ( r$4 ,,titanium ,titanium is a v widely di/ribut$ elem5t 9 nature1 be+ f\nd 9 almo/ all soils1 9 _m rocks1 & ev5 9 plant & animal tissues4 ,x is n v abundant 9 any "o locality1 & x possesses little comm]cial value save 9 connection ) ! iron indu/ry4 ,its mo/ common ore is rutile 7,ti,o#b71 :i* resembles silica 9 _m respects4 ,9 bo? physical & *emical prop]ties titanium resembles silicon1 ?\gh x is some:at m metallic 9 "*4 ,?is resemblance is mo/ m>k$ 9 ! acids ( titanium4 ,x n only =ms metatitanic & or?otitanic acids b a great v>iety ( polytitanic acids z well4 ,,boron ,occurr5ce4 ,boron is nev] f\nd free 9 nature4 ,x occurs z boric acid 7,h#c;,,bo#c71 & 9 salts ( polyboric acids1 :i* usually h v complicat$ =mulas4 ,prep>ation & prop]ties4 ,boron c be prep>$ f its oxide by r$uction ) magnesium1 exactly z 9 ! case ( silicon4 ,x resembles silicon v /rik+ly 9 its prop]ties4 ,x occurs 9 sev]al allotropic =ms1 is v h>d :5 cry/alliz$1 & is r inactive t[>d reag5ts4 ,x =ms a hydride1 ,,bh#c1 & comb9es directly ) ! elem5ts ( ! *lor9e family4 ,boron fluoride 7,,bf#c7 is v simil> to silicon fluoride 9 its mode ( =mation & *emical prop]ties4 ,boric oxide 7,b#b,o#c74 ,boron =ms "o well-kn[n oxide1 ,b#b,o#c1 call$ boric anhydride4 ,x is =m$ z a glassy mass by heat+ boric acid to a high temp]ature4 ,x absorbs wat] v readily1 unit+ ) x to =m boric acid aga93 ,b#b,o#c #c;,h#b,o #b;,h#c;,,bo#c4 ,9 ?is respect x diff]s f silicon dioxide1 :i* w n comb9e directly ) wat]4 ,boric acid 7,h#c;,,bo#c74 ,?is is f\nd 9 nature 9 consid]able quantities & =ms "o ( ! *ief s\rces ( boron comp\nds4 ,x is f\nd dissolv$ 9 ! wat] ( hot spr+s 9 "s localities1 p>ticul>ly 9 ,italy4 ,be+ volatile ) /eam1 ! vapor :i* escapes f ^! spr+s has "s boric acid 9 x4 ,x is easily obta9$ f ^! s\rces by cond5sation & evaporation1 ! necess>y heat be+ suppli$ by o!r hot spr+s4 ,boric acid cry/allizes 9 pe>ly flakes1 :i* are greasy to ! t\*4 ,9 ! laboratory x is easily prep>$ by treat+ a /rong1 hot solution ( borax ) sulphuric acid4 ,boric acid be+ sp>+ly soluble 9 wat] cry/allizes out on cool+3 ,na#b;,b#d,o#g #e;,h#b,o ,h#b,,s#d ,na#b,,s#d #d;,h#c;,,bo#c4 ,! sub/ance is a mild antiseptic1 & on ?is acc\nt is (t5 us$ 9 m$ic9e & z a pres]vative = cann$ foods & milk4 ,metaboric & polyboric acids4 ,:5 boric acid is g5tly heat$ x is conv]t$ into metaboric acid 7,,hbo#b73 ,h#c;,,bo#c ,,hbo#b ,h#b,o4 ,on heat+ metaboric acid to a some:at high] temp]ature tetraboric acid 7,h#b;,b#d,o#g7 is =m$3 #d;,,hbo#b ,h#b;,b#d,o#g ,h#b,o4 ,_m o!r complex acids ( boron are kn[n4 ,borax4 ,borax is ! sodium salt ( tetraboric acid1 hav+ ! =mula ,na#b;,b#d,o#gaj ,h#b,o4 ,x is f\nd 9 "s arid c\ntries1 z s\!rn ,cali=nia & ,tibet1 b is n[ made comm]cially f ! m9]al colemanite1 :i* is ! calcium salt ( a complex boric acid4 ,:5 ?is is treat$ ) a solution ( sodium c>bonate1 calcium c>bonate is precipitat$ & borax cry/allizes f ! solution4 ,:5 heat$ borax at fir/ swells up greatly1 ow+ to ! expulsion ( ! wat] ( cry/allization1 & !n melts to a cle> glass4 ,?is glass has ! prop]ty ( easily dissolv+ _m metallic oxides1 & on ?is acc\nt borax is us$ z a flux 9 sold]+1 = ! purpose ( remov+ f ! metallic surfaces to be sold]$ ! film ( oxide ) :i* !y are likely to be cov]$4 ,^! oxides (t5 give a *>act]i/ic color to ! cle> borax glass1 & borax beads are !re=e (t5 us$ 9 te/+ = ! pres5ce ( metals1 in/ead ( ! metaphosphoric acid bead already describ$4 ,! reason t metallic oxides dissolve 9 borax is t borax conta9s an excess ( acid anhydride1 z c be m easily se5 if its =mula is writt5 #b,na,b,o#b ,b#b,o#c4 ,! metallic oxide comb9es ) ?is excess ( acid anhydride1 =m+ a mix$ salt ( metaboric acid4 ,borax is ext5sively us$ z a con/itu5t ( enamels & glazes = bo? metal w>e & pott]y4 ,x is also us$ z a flux 9 sold]+ & braz+1 & 9 dome/ic ways x s]ves z a mild alkali1 z a pres]vative = meats1 & 9 a great v>iety ( less important applications4 ,,ex]cises #a4 ,acc\nt = ! fact t a solution ( borax 9 wat] is alkal9e4 #b4 ,:at weight ( wat] ( cry/allization does #a kg4 ( borax conta98 #c4 ,:5 a conc5trat$ solution ( borax acts on silv] nitrate a borate ( silv] is =m$4 ,if ! solution ( borax is dilute1 h[ev]1 an hydroxide ( silv] =ms4 ,acc\nt = ?is diff]5ce 9 behavior4 ,,*apt] ,,xxii ,,! ,,metals ,! metals4 ,! elem5ts :i* rema9 to be consid]$ are kn[n collectively z ! metals4 ,!y are also call$ ! base-=m+ elem5ts1 s9ce _! hydroxides are bases4 ,a metal may !re=e be def9$ z an elem5t ^: hydroxide is a base4 ,:5 a base dissolves 9 wat] ! hydroxyl gr\ps =m ! anions1 :ile ! metallic elem5t =ms ! cations4 ,f ?is /&po9t a metal c be def9$ z an elem5t capable ( =m+ simple cations 9 solution4 ,! di/9ction betwe5 a metal & a non-metal is n a v %>p "o1 s9ce ! hydroxides ( a numb] ( elem5ts act z bases "u "s conditions & z acids "u o!rs4 ,we h se5 t antimony is an elem5t ( ?is k9d4 ,occurr5ce ( metals 9 nature4 ,a few ( ! metals are f\nd 9 nature 9 ! free /ate4 ,among ^! are gold1 plat9um1 & frequ5tly copp]4 ,!y are usually f\nd comb9$ ) o!r elem5ts 9 ! =m ( oxides or salts ( v>i\s acids4 ,silicates1 c>bonates1 sulphides1 & sulphates are ! mo/ abundant salts4 ,all inorganic sub/ances occurr+ 9 nature1 :e!r !y conta9 a metal or n1 are call$ m9]als4 ,^? m9]als f :i* a useful sub/ance c be extract$ are call$ ores ( ! sub/ance4 ,^! two t]ms are mo/ frequ5tly us$ 9 connection ) ! metals4 ,extraction ( metals1--metallurgy4 ,! process ( extract+ a metal f its ores is call$ ! metallurgy ( ! metal4 ,! metallurgy ( ea* metal pres5ts peculi>ities ( its own1 b !re are sev]al me?ods ( g5]al application :i* are v frequ5tly employ$4 #a4 ,r$uction ( an oxide ) c>bon4 ,_m ( ! metals occur 9 nature 9 ! =m ( oxides4 ,:5 ^! oxides are heat$ to a high temp]ature ) c>bon ! oxyg5 comb9es ) x & ! metal is set free4 ,iron1 = example1 occurs l>gely 9 ! =m ( ! oxide ,fe#b,o#c4 ,:5 ?is is heat$ ) c>bon ! reaction express$ 9 ! foll[+ equation takes place3 ,fe#b,o#c #c ,c #b ,fe #c ,,co4 ,_m ores o!r ?an oxides may be *ang$ into oxides :i* c !n be r$uc$ by c>bon4 ,! conv]sion ( su* ores into oxides is g5]ally accompli%$ by heat+1 & ?is process is call$ roa/+4 ,_m c>bonates & hydroxides decompose directly into ! oxide on heat+4 ,sulphides1 on ! o!r h&1 mu/ be heat$ 9 a curr5t ( air1 ! oxyg5 ( ! air ent]+ into ! reaction4 ,! foll[+ equations w s]ve to illu/rate ^! *anges 9 ! case ( ! ores ( iron3 ,fe,c,o#c ,fe,o ,,co#b1 #b;,fe7,,oh7#c ,fe#b,o#c #c;,h#b,o1 #b;,fe,s#b #aa,o ,fe#b,o#c #d,,s#b4 #b4 ,r$uction ( an oxide ) alum9ium4 ,n all oxides1 h[ev]1 c be r$uc$ by c>bon4 ,9 su* cases alum9ium may be us$4 ,?us *romium may be obta9$ 9 accordance ) ! foll[+ equation3 ,cr#b,o#c #b ,al #b ,cr ,al#b,o#c4 ,?is me?od is a comp>atively new "o1 hav+ be5 br\ght into use by ! ,g]man *emi/ ,golds*midt2 h5ce x is sometimes call$ ! ,golds*midt me?od4 #c4 ,electrolysis4 ,9 rec5t ye>s increas+ use is be+ made ( ! electric curr5t 9 ! prep>ation ( metals4 ,9 "s cases ! sep>ation ( ! metal f its comp\nds is accompli%$ by pass+ ! curr5t ?r\gh a solution ( a suitable salt ( ! metal1 ! metal usually be+ deposit$ ^u ! ca?ode4 ,9 o!r cases ! curr5t is pass$ ?r\gh a fus$ salt ( ! metal1 ! *loride be+ be/ adapt$ to ?is purpose4 ,electro-*emical indu/ries4 ,mo/ ( ! electro-*emical indu/ries ( ! c\ntry are c>ri$ on :]e wat] p[] is abundant1 s9ce ?is furni%es ! *eape/ means = ! g5]ation ( electrical en]gy4 ,niag>a ,falls is ! mo/ important locality 9 ?is c\ntry = su* indu/ries1 & _m diff]5t electro-*emical products are manufactur$ !re4 ,"s indu/ries dep5d ^u electrolytic processes1 :ile 9 o!rs ! electrical en]gy is us$ m]ely z a s\rce ( heat 9 electric furnaces4 ,prep>ation ( comp\nds ( ! metals4 ,s9ce ! comp\nds ( ! metals are s num]\s & v>i$ 9 "*1 !re are _m ways ( prep>+ !m4 ,9 _m cases ! prop]ties ( ! sub/ance to be prep>$1 or ! mat]ial available = its prep>ation1 sugge/ a r unusual way4 ,!re are1 h[ev]1 a numb] ( g5]al pr9ciples :i* are con/antly appli$ 9 ! prep>ation ( ! comp\nds ( ! metals1 & a cle> und]/&+ ( !m w save mu* "t & ef=t 9 rememb]+ ! details 9 any giv5 case4 ,! mo/ important ( ^! g5]al me?ods = ! prep>ation ( comp\nds are ! foll[+3 #a4 ,by direct union ( two elem5ts4 ,?is is usually accompli%$ by heat+ ! two elem5ts toge!r4 ,?us ! sulphides1 *lorides1 & oxides ( a metal c g5]ally be obta9$ 9 ?is way4 ,! foll[+ equations s]ve z examples ( ?is me?od3 ,fe ,s ,fe,s1 ,mg ,o ,mg,o1 ,cu #b;,cl ,cu,cl#b4 #b4 ,by ! decomposition ( a comp\nd4 ,?is decomposition may be br\ght ab\t ei!r by heat alone or by ! comb9$ action ( heat & a r$uc+ ag5t4 ,?us :5 ! nitrate ( a metal is heat$ ! oxide ( ! metal is usually obta9$4 ,copp] nitrate1 = example1 decomposes z foll[s3 ,cu7,,no#c7b ,cu,o #b,,no#b ,o4 ,simil>ly ! c>bonates ( ! metals yield oxides1 ?us3 ,ca,c,o#c ,ca,o ,,co#b4 ,mo/ ( ! hydroxides =m an oxide & wat] :5 heat$3 #b;,al7,,oh7#c ,al#b,o#c #c;,h#b,o4 ,:5 heat$ ) c>bon1 sulphates are r$uc$ to sulphides1 ?us3 ,ba,s,o#d #b;,c ,ba,s #b;,,co#b4 #c4 ,me?ods bas$ on equilibrium 9 solution4 ,9 ! prep>ation ( comp\nds ! fir/ requisite is t ! reactions *os5 %all be ( su* a k9d z w g on to completion4 ,9 ! *apt] on *emical equilibrium x 0 %[n t reactions 9 solution may become complete 9 ei!r ( ?ree ways3 7#a7 a gas may be =m$ :i* escapes f solution2 7#b7 an insoluble solid may be =m$ :i* precipitates2 7#c7 two diff]5t ions may comb9e to =m undissociat$ molecules4 ,by ! judici\s selection ( mat]ials ^! pr9ciples may be appli$ to ! prep>ation ( a great v>iety ( comp\nds1 & illu/rations ( su* me?ods w v frequ5tly be f\nd 9 ! subsequ5t pages4 #d4 ,by fusion me?ods4 ,x sometimes happ5s t sub/ances :i* are insoluble 9 wat] & 9 acids1 & :i* _c !re=e be br\ght into d\ble decomposition 9 ! usual way1 are soluble 9 o!r liquids1 & :5 dissolv$ 9 !m c be decompos$ & conv]t$ into o!r desir$ comp\nds4 ,?us b>ium sulphate is n soluble 9 wat]1 & sulphuric acid1 be+ less volatile ?an mo/ o!r acids1 _c easily be driv5 out f ?is salt ,:5 br\ght into contact ) melt$ sodium c>bonate1 h[ev]1 x dissolves 9 x1 & s9ce b>ium c>bonate is insoluble 9 melt$ sodium c>bonate1 d\ble decomposition takes place3 ,na#b;,,co#c ,ba,s,o#d ,ba,c,o#c ,na#b,,s#d4 ,on dissolv+ ! cool$ mixture 9 wat] ! sodium sulphate =m$ 9 ! reaction1 toge!r ) any excess ( sodium c>bonate :i* may be pres5t1 dissolves4 ,! b>ium c>bonate c !n be filt]$ (f & conv]t$ into any desir$ salt by ! processes already describ$4 #e4 ,by ! action ( metals on salts ( o!r metals4 ,:5 a /rip ( z9c is plac$ 9 a solution ( a copp] salt ! copp] is precipitat$ & an equival5t quantity ( z9c passes into solution3 ,zn ,cu,s,o#d ,cu ,zn,s,o#d4 ,9 l mann] copp] w precipitate silv] f its salts3 ,cu ,ag#b,,s#d #b;,ag ,cu,s,o#d4 ,x is possible to tabulate ! metals 9 su* a way t any "o ( !m 9 ! table w precipitate any "o foll[+ x f its salts4 ,! foll[+ is a li/ ( "s ( ! common] metals arrang$ 9 ?is way3 ,z9c ,iron ,t9 ,lead ,copp] ,bismu? ,m]cury ,silv] ,gold ,accord+ to ?is table copp] w precipitate bismu?1 m]cury1 silv]1 or gold f _! salts1 & w 9 turn be precipitat$ by z9c1 iron1 t91 or lead4 ,advantage is tak5 ( ?is pr9ciple 9 ! purification ( "s ( ! metals1 & occasionally 9 ! prep>ation ( metals & _! comp\nds4 ,important insoluble comp\nds4 ,s9ce precipitates play s important a "p 9 ! reactions :i* sub/ances und]go1 z well z 9 ! prep>ation ( _m *emical comp\nds1 x is important to "k :at sub/ances are insoluble4 ,kn[+ ?is1 we c 9 _m cases pr$ict reactions "u c]ta9 conditions1 & are assi/$ 9 devis+ ways to prep>e desir$ comp\nds4 ,:ile !re is no g5]al rule :i* w enable "o to =etell ! solubility ( any giv5 comp\nd1 nev]!less a few g5]al /atem5ts c be made :i* w be ( mu* assi/ance4 #a4 ,hydroxides4 ,all hydroxides are insoluble save ^? ( ammonium1 sodium1 potassium1 calcium1 b>ium1 & /rontium4 #b4 ,nitrates4 ,all nitrates are soluble 9 wat]4 #c4 ,*lorides4 ,all *lorides are soluble save silv] & m]cur\s *lorides4 7,lead *loride is b slightly soluble47 #d4 ,sulphates4 ,all sulphates are soluble save ^? ( b>ium1 /rontium1 & lead4 7,sulphates ( silv] & calcium are only mod]ately soluble47 #e4 ,sulphides4 ,all sulphides are insoluble save ^? ( ammonium1 sodium1 & potassium4 ,! sulphides ( calcium1 b>ium1 /rontium1 & magnesium are insoluble 9 wat]1 b are *ang$ by hydrolysis into acid sulphides :i* are soluble4 ,on ?is acc\nt !y _c be prep>$ by precipitation4 #f4 ,c>bonates1 phosphates1 & silicates4 ,all normal c>bonates1 phosphates1 & silicates are insoluble save ^? ( ammonium1 sodium & potassium4 ,,ex]cises #a4 ,write equations repres5t+ f\r diff]5t ways = prep>+ ,cu7,,no#c7b4 #b4 ,write equations repres5t+ six diff]5t ways = prep>+ ,zn,s,o#d4 #c4 ,write equations = two reactions to illu/rate ea* ( ! ?ree ways 9 :i* reactions 9 solutions may become complete4 #d4 ,give "o or m me?ods = prep>+ ea* ( ! foll[+ comp\nds3 ,ca,cl#b1 ,pb,cl#b1 ,ba,s,o#d1 ,ca,c,o#c1 7,,nh#d7b,s1 ,ag#b,s1 ,pb,o1 ,cu7,,oh7#b 7= solubilities1 see la/ p>agraph ( *apt]74 ,/ate 9 ea* case ! g5]al pr9ciple involv$ 9 ! me?od ( prep>ation *os54 ,,*apt] ,,xxiii ,,! ,,alkali ,,metals ,,symbol ,,atomic ,,d5sity ,,melt+ ,,fir/ ,,prep>$ ,,weight ,,po9t ,li?ium ,li #g4jc #j4ei #ahf4 ,davy #ahbj ,sodium ,na #bc4je #j4ig #ig4f #ahjg ,potassium ,k #ci4ae #j4hg #fb4e #ahjg ,rubidium ,rb #he4e #a4eb #ch4e ,buns5 #ahfa ,csium ,cs #acb4i #a4hh #bf4e #ahfj ,! family4 ,! metals li/$ 9 ! above table con/itute ! ev5 family 9 ,gr\p ,i 9 ! p]iodic arrangem5t ( ! elem5ts1 & !re=e =m a natural family4 ,! "n alkali metals is commonly appli$ to ! family = ! reason t ! hydroxides ( ! mo/ famili> memb]s ( ! family1 namely sodium & potassium1 h long be5 call$ alkalis4 #a4 ,occurr5ce4 ,:ile none ( ^! metals occur free 9 nature1 _! comp\nds are v widely di/ribut$1 be+ especially abundant 9 sea & m9]al wat]s1 9 salt b$s1 & 9 _m rocks4 ,only sodium & potassium occur 9 abundance1 ! o!rs be+ r>ely f\nd 9 any consid]able quantity4 #b4 ,prep>ation4 ,! metals are mo/ conv5i5tly prep>$ by ! electrolysis ( _! fus$ hydroxides or *lorides1 ?\gh x is possible to prep>e !m by r$uc+ _! oxides or c>bonates ) c>bon4 #c4 ,prop]ties4 ,!y are s(t1 light metals1 hav+ l[ melt+ po9ts & small d5sities1 z is indicat$ 9 ! table4 ,_! melt+ po9ts v>y inv]sely ) _! atomic weights1 :ile _! d5sities 7sodium except$7 v>y directly ) ^!4 ,! pure metals h a silv]y lu/] b t>ni% at once :5 expos$ to ! air1 ow+ to ! =mation ( a film ( oxide ^u ! surface ( ! metal4 ,!y are !re=e pres]v$ 9 "s liquid1 su* z coal oil1 :i* conta9s no oxyg54 ,because ( _! /rong aff9ity = oxyg5 !y decompose wat] ) great ease1 =m+ hydroxides & lib]at+ hydrog5 9 accordance ) ! equation ,m ,h#b,o ,,moh ,h1 :]e ,m /&s = any "o ( ^! metals4 ,^! hydroxides are :ite solids2 !y are readily soluble 9 wat] & possess v /rong basic prop]ties4 ,^! bases are ne>ly equal 9 /r5g?1 t is1 !y all dissociate 9 wat] to ab\t ! same ext5t4 #d4 ,comp\nds4 ,! alkali metals almo/ always act z unival5t elem5ts 9 ! =mation ( comp\nds1 ! composition ( :i* c be repres5t$ by su* =mulas z ,,mh1 ,m,cl1 ,,mno#c1 ,m#b,,s#d1 ,m#c,,po#d4 ,^! comp\nds1 :5 dissolv$ 9 wat]1 dissociate 9 su* a way z to =m simple1 unival5t metallic ions :i* are colorless4 ,) ! exception ( li?ium ^! metals =m v few insoluble comp\nds1 s t x is n (t5 t precipitates conta9+ !m are obta9$4 ,only sodium & potassium w be /udi$ 9 detail1 s9ce ! o!r metals ( ! family are ( relatively small importance4 ,! comp\nds ( sodium & potassium are s simil> 9 prop]ties t !y c be us$ int]*angeably = mo/ purposes4 ,o!r ?+s be+ equal1 ! sodium comp\nds are prep>$ 9 pref]5ce to ^? ( potassium1 s9ce !y are *eap]4 ,:5 a giv5 sodium comp\nd is deliquesc5t1 or is s soluble t x is difficult to purify1 ! correspond+ potassium comp\nd is prep>$ 9 its /ead1 provid$ its prop]ties are m desirable 9 ^! respects4 ,,sodium ,occurr5ce 9 nature4 ,l>ge deposits ( sodium *loride h be5 f\nd 9 v>i\s p>ts ( ! _w1 & ! wat] ( ! ocean & ( _m lakes & spr+s conta9s notable quantities ( x4 ,! elem5t also occurs z a con/itu5t ( _m rocks & is !re=e pres5t 9 ! soil =m$ by _! dis9tegration4 ,! m9]al cryolite 7,na#c;,al,f#f7 is an important sub/ance1 & ! nitrate1 c>bonate1 & borate also occur 9 nature4 ,prep>ation4 ,9 #ahjg ,sir ,humphry ,davy succe$$ 9 prep>+ v small quantities ( metallic sodium by ! electrolysis ( ! fus$ hydroxide4 ,on acc\nt ( ! co/ ( electrical en]gy x 0 = _m ye>s f\nd m economical to prep>e x by r$uc+ ! c>bonate ) c>bon 9 accordance ) ! foll[+ equation3 ,na#b;,,co#c #b;,c #b,na #c;,,co4 ,! co/ ( g5]at+ ! electric curr5t has be5 dim9i%$ to su* an ext5t1 h[ev]1 t x is n[ m economical to prep>e sodium by ,davy's orig9al me?od1 namely1 by ! electrolysis ( ! fus$ hydroxide or *loride4 ,:5 ! *loride is us$ ! process is difficult to manage1 ow+ to ! high] temp]ature requir$ to keep ! electrolyte fus$1 & because ( ! corrod+ action ( ! fus$ *loride ^u ! conta9+ vessel4 ,illu/ration3 ,,sir ,,humphry ,,davy 7,engli%7 7#aggh-ahbi7 ,isolat$ sodium1 li?ium1 potassium1 b>ium1 /rontium1 & calcium by means ( electrolysis2 demon/rat$ ! elem5t>y nature ( *lor9e2 inv5t$ ! safety lamp2 discov]$ ! /upefy+ effects ( nitr\s oxide ,te*nical prep>ation4 ,! sodium hydroxide is melt$ 9 a cyl9drical iron vessel 7,fig4 #gf7 ?r\gh ! bottom ( :i* rises ! ca?ode ,k4 ,! anodes ,a1 sev]al 9 numb]1 are susp5d$ ar\nd ! ca?ode f above4 ,a cyl9drical vessel ,c floats 9 ! fus$ alkali directly ov] ! ca?ode1 & "u ?is cap ! sodium & hydrog5 lib]at$ at ! ca?ode collect4 ,! hydrog5 escapes by lift+ ! cov]1 & ! sodium1 protect$ f ! air by ! hydrog51 is skimm$ or dra9$ (f f "t to "t4 ,oxyg5 is set free ^u ! anode & escapes into ! air ?r\gh ! op5+s ,o )\t com+ into contact ) ! sodium or hydrog54 ,?is process is c>ri$ on ext5sively at ,niag>a ,falls4 ,illu/ration3 ,fig4 #gf ,prop]ties4 ,sodium is a silv]-:ite metal ab\t z heavy z wat]1 & s s(t t x c be mold$ easily by ! f+]s or press$ into wire4 ,x is v active *emically1 comb9+ ) mo/ ( ! non-metallic elem5ts1 su* z oxyg5 & *lor9e1 ) great en]gy4 ,x w (t5 )draw ^! elem5ts f comb9ation ) o!r elem5ts1 & is ?us able to decompose wat] & ! oxides & *lorides ( _m metals4 ,sodium p]oxide 7,na,o74 ,s9ce sodium is a unival5t elem5t we %\ld expect x to =m an oxide ( ! =mula ,na#b,o4 ,:ile su* an oxide c be prep>$1 ! p]oxide 7,na,o7 is mu* bett] kn[n4 ,x is a yell[i%-:ite p[d] made by burn+ sodium 9 air4 ,its *ief use is z an oxidiz+ ag5t4 ,:5 heat$ ) oxidizable sub/ances x gives up a "p ( its oxyg51 z %[n 9 ! equation #b,na,o ,na#b,o ,o4 ,wat] decomposes x 9 accordance ) ! equation #b,na,o #b;,h#b,o #b,na,o,h ,h#b,o#b4 ,acids act readily ^u x1 =m+ a sodium salt & hydrog5 p]oxide3 #b,na,o #b;,h,cl #b,na,cl ,h#b,o#b4 ,9 ^! la/ two reactions ! hydrog5 dioxide =m$ may decompose into wat] & oxyg5 if ! temp]ature is all[$ to rise3 ,h#b,o#b ,h#b,o ,o4 ,p]oxides4 ,x w be rememb]$ t b>ium dioxide 7,ba,o#b7 yields hydrog5 dioxide :5 treat$ ) acids1 & t manganese dioxide gives up oxyg5 :5 heat$ ) sulphuric acid4 ,oxides :i* yield ei!r hydrog5 dioxide or oxyg5 :5 treat$ ) wat] or an acid are call$ p]oxides4 ,sodium hydroxide 7cau/ic soda7 7,na,o,h74 #a4 ,prep>ation4 ,sodium hydroxide is prep>$ comm]cially by sev]al processes4 7a7 ,9 ! old] process1 /ill 9 ext5sive use1 sodium c>bonate is treat$ ) calcium hydroxide susp5d$ 9 wat]4 ,calcium c>bonate is precipitat$ accord+ to ! equation ,na#b;,,co#c ,ca7,,oh7#b ,ca,c,o#c #b,na,o,h4 ,! dilute solution ( sodium hydroxide1 filt]$ f ! calcium c>bonate1 is evaporat$ to a pa/e & is !n p\r$ into molds to solidify4 ,x is sold 9 ! =m ( sl5d] /icks4 7b7 ,! new] me?ods dep5d ^u ! electrolysis ( sodium *loride4 ,9 ! ,ca/n] process a solution ( salt is electrolyz$1 ! reaction be+ express$ z foll[s3 ,na,cl ,h#b,o ,na,o,h ,h ,cl4 ,! *lor9e escapes z a gas1 & by an +5i\s me*anical device ! sodium hydroxide is prev5t$ f mix+ ) ! salt 9 ! solution4 ,9 ! ,ack] process ! electrolyte is fus$ sodium *loride4 ,! *lor9e is evolv$ z a gas at ! anode1 :ile ! sodium alloys ) ! melt$ lead :i* =ms ! ca?ode4 ,:5 ?is alloy is treat$ ) wat] ! foll[+ reaction takes place3 ,na ,h#b,o ,na,o,h ,h4 ,illu/ration3 ,fig4 #gg ,te*nical process4 ,a sket* ( an ,ack] furnace is repres5t$ 9 ,fig4 #gg4 ,! furnace is an irregul>ly %ap$ ca/-iron box1 divid$ into ?ree comp>tm5ts1 ,a1 ,b1 & ,c4 ,comp>tm5t ,a is l9$ ) magnesia brick4 ,comp>tm5ts ,b & ,c are fill$ ) melt$ lead1 :i* also cov]s ! bottom ( ,a to a dep? ( ab\t an in*4 ,above ?is lay] 9 ,a is fus$ salt1 into :i* dip c>bon anodes ,d4 ,! metallic box & melt$ lead is ! ca?ode4 ,:5 ! furnace is 9 op]ation *lor9e is evolv$ at ! anodes1 & is drawn away ?r\gh a pipe 7n repres5t$7 to ! blea*+-p[d] *amb]s4 ,sodium is set free at ! surface ( ! melt$ lead 9 ,a1 & at once alloys ) x4 ,?r\gh ! pipe ,e a p[]ful jet ( /eam is driv5 ?r\gh ! lead 9 ,b upw>ds into ! n>r[ tube ,f4 ,?is =ces ! lead alloy up ?r\gh ! tube & ov] into ! *amb] ,g4 ,9 ?is process ! /eam is decompos$ by ! sodium 9 ! alloy1 =m+ melt$ sodium hydroxide & hydrog54 ,! melt$ lead & sodium hydroxide sep>ate into two lay]s 9 ,g1 & ! sodium hydroxide1 be+ on top1 ov]fl[s into tanks f :i* x is drawn (f & pack$ 9 metallic drums4 ,! lead is return$ to ! o!r comp>tm5ts ( ! furnace by a pipe lead+ f ,h to ,i4 ,comp>tm5t ,c s]ves m]ely z a res]voir = excess ( melt$ lead4 #b4 ,prop]ties4 ,sodium hydroxide is a :ite1 cry/all9e1 brittle sub/ance :i* rapidly absorbs wat] & c>bon dioxide f ! air4 ,z ! "n 7cau/ic soda7 indicates1 x is a v corrosive sub/ance1 hav+ a dis9tegrat+ action on mo/ animal & vegetable tissues4 ,x is a /rong base4 ,x is us$ 9 a great _m *emical indu/ries1 & "u ! "n ( lye is employ$ to a small ext5t z a cleans+ ag5t = h\sehold purposes4 ,sodium *loride 7common salt7 7,na,cl74 #a4 ,prep>ation4 ,sodium *loride1 or common salt1 is v widely di/ribut$ 9 nature4 ,?ick /rata1 evid5tly deposit$ at "o "t by ! evaporation ( salt wat]1 are f\nd 9 _m places4 ,9 ! ,unit$ ,/ates ! mo/ important localities = salt are ,new ,york1 ,mi*igan1 ,ohio1 & ,kansas4 ,sometimes ! salt is m9$1 especially if x is 9 ! pure =m call$ rock salt4 ,m frequ5tly a /rong br9e is pump$ f deep wells sunk into ! salt deposit1 & is !n evaporat$ 9 l>ge pans until ! salt cry/allizes out4 ,! cry/als are 9 ! =m ( small cubes & conta9 no wat] ( cry/allization2 "s wat] is1 h[ev]1 held 9 cavities 9 ! cry/als & causes ! salt to decrepitate :5 heat$4 #b4 ,uses4 ,s9ce salt is s abundant 9 nature x =ms ! />t+ po9t 9 ! prep>ation ( all comp\nds conta9+ ei!r sodium or *lor9e4 ,?is includes _m sub/ances ( ! highe/ importance to civilization1 su* z soap1 glass1 hydro*loric acid1 soda1 & blea*+ p[d]4 ,enorm\s quantities ( salt are !re=e produc$ ea* ye>4 ,small quantities are ess5tial to ! life ( man & animals4 ,pure salt does n absorb moi/ure2 ! fact t ord9>y salt becomes moi/ 9 air is n due to a prop]ty ( ! salt1 b to impurities commonly occurr+ 9 x1 especially calcium & magnesium *lorides4 ,sodium sulphate 7,glaub]'s salt7 7,na#b,,s#daj;,h#b,o74 ,?is salt is prep>$ by ! action ( sulphuric acid ^u sodium *loride1 hydro*loric acid be+ =m$ at ! same "t3 #b,na,cl ,h#b,,s#d ,na#b,,s#d #b;,h,cl4 ,"s sodium sulphate is prep>$ by ! reaction repres5t$ 9 ! equation ,mg,s,o#d #b,na,cl ,na#b,,s#d ,mg,cl#b4 ,! magnesium sulphate requir$ = ?is reaction is obta9$ 9 l>ge quantities 9 ! manufacture ( potassium *loride1 & be+ ( little value = any o!r purpose is us$ 9 ?is way4 ,! reaction dep5ds ^u ! fact t sodium sulphate is ! lea/ soluble ( any ( ! f\r factors 9 ! equation1 & !re=e cry/allizes out :5 hot1 saturat$ solutions ( magnesium sulphate & sodium *loride are mix$ toge!r & ! result+ mixture cool$4 ,sodium sulphate =ms l>ge effloresc5t cry/als4 ,! salt is ext5sively us$ 9 ! manufacture ( sodium c>bonate & glass4 ,small quantities are us$ 9 m$ic9e4 ,sodium sulphite 7,na#b,,s#cg;,h#b,o74 ,sodium sulphite is prep>$ by ! action ( sulphur dioxide ^u solutions ( sodium hydroxide1 ! reaction be+ analog\s to ! action ( c>bon dioxide ^u sodium hydroxide4 ,l ! c>bonate1 ! sulphite is readily decompos$ by acids3 ,na#b,,s#c #b;,h,cl #b,na,cl ,h#b,o ,,s#b4 ,because ( ?is reaction sodium sulphite is us$ z a conv5i5t s\rce ( sulphur dioxide4 ,x is also us$ z a dis9fectant & a pres]vative4 ,sodium ?iosulphate 7hyposulphite ( soda or hypo7 7,na#b,s#b,o#ce;,h#b,o74 ,?is salt1 commonly call$ sodium hyposulphite1 or m]ely hypo1 is made by boil+ a solution ( sodium sulphite ) sulphur3 ,na#b,,s#c ,s ,na#b,s#b,o#c4 ,x is us$ 9 photography & 9 ! blea*+ indu/ry1 to absorb ! excess ( *lor9e :i* is left ^u ! blea*$ fabrics4 ,?io comp\nds4 ,! prefix ?io means sulphur4 ,x is us$ to designate sub/ances :i* may be reg>d$ z d]iv$ f oxyg5 comp\nds by replac+ ! :ole or a "p ( _! oxyg5 ) sulphur4 ,! ?iosulphates may be reg>d$ z sulphates 9 :i* "o atom ( oxyg5 has be5 replac$ by an atom ( sulphur4 ,?is may be se5 by comp>+ ! =mula ,na#b,,s#d 7sodium sulphate7 ) ! =mula ,na#b,s#b,o#c 7sodium ?iosulphate74 ,sodium c>bonate 7sal soda77,na#b;,,co#caj;,h#b,o74 ,!re are two diff]5t me?ods n[ employ$ 9 ! manufacture ( ?is important sub/ance4 #a4 ,le ,blanc process4 ,?is old] process involves sev]al di/9ct reactions1 z %[n 9 ! foll[+ equations4 7a7 ,sodium *loride is fir/ conv]t$ into sodium sulphate3 #b,na,cl ,h#b,,s#d ,na#b,,s#d #b;,h,cl4 7b7 ,! sodium sulphate is next r$uc$ to sulphide by heat+ x ) c>bon3 ,na#b,,s#d #b;,c ,na#b,s #b;,,co#b4 7c7 ,! sodium sulphide is !n heat$ ) calcium c>bonate1 :5 d\ble decomposition takes place3 ,na#b,s ,ca,c,o#c ,ca,s ,na#b;,,co#c4 ,te*nical prep>ation ( sodium c>bonate4 ,9 a manufactur+ plant ! la/ two reactions take place 9 "o process4 ,sodium sulphate1 coal1 & p[d]$ lime/one are heat$ toge!r to a r high temp]ature4 ,! coal r$uces ! sulphate to sulphide1 :i* 9 turn reacts ^u ! calcium c>bonate4 ,"s lime/one is decompos$ by ! heat1 =m+ calcium oxide4 ,:5 treat$ ) wat] ! calcium oxide is *ang$ into hydroxide1 & ?is prev5ts ! wat] f decompos+ ! insoluble calcium sulphide4 ,! crude product ( ! process is a h>d black cake call$ black a%4 ,on dige/+ ?is mass ) wat] ! sodium c>bonate passes into solution4 ,! pure c>bonate is obta9$ by evaporation ( ?is solution1 cry/alliz+ f x 9 cry/als ( ! =mula ,na#b;,,co#caj;,h#b,o4 ,s9ce ov] #fj ( ?is salt is wat]1 ! cry/als are sometimes heat$ until x is driv5 (f4 ,! product is call$ calc9$ soda1 & is1 ( c\rse1 m valuable ?an ! cry/alliz$ salt4 #b4 ,solvay process4 ,?is m mod]n process dep5ds ^u ! reactions repres5t$ 9 ! equations ,na,cl ,,nh#d;,,hco#c ,na,h,c,o#c ,,nh#d;,cl1 #b,na,h,c,o#c ,na#b;,,co#c ,h#b,o ,,co#b4 ,! reason ! fir/ reaction takes place is t sodium hydrog5 c>bonate is sp>+ly soluble 9 wat]1 :ile ! o!r comp\nds are freely soluble4 ,:5 /rong solutions ( sodium *loride & ( ammonium hydrog5 c>bonate are br\ght toge!r ! sp>+ly soluble sodium hydrog5 c>bonate is precipitat$4 ,?is is conv]t$ into ! normal c>bonate by heat+1 ! reaction be+ repres5t$ 9 ! second equation4 ,te*nical prep>ation4 ,9 ! ,solvay process a v conc5trat$ solution ( salt is fir/ saturat$ ) ammonia gas1 & a curr5t ( c>bon dioxide is !n conduct$ into ! solution4 ,9 ?is way ammonium hydrog5 c>bonate is =m$3 ,,nh#c ,h#b,o ,,co#b ,,nh#d;,,hco#c4 ,?is ent]s into d\ble decomposition ) ! salt1 z %[n 9 ! fir/ equation "u ! ,solvay process4 ,aft] ! sodium hydrog5 c>bonate has be5 precipitat$ ! "m liquors conta9+ ammonium *loride are treat$ ) lime3 #b,,nh#d;,cl ,ca,o ,ca,cl#b #b ,,nh#c ,h#b,o4 ,! lime is obta9$ by burn+ lime/one3 ,ca,c,o#c ,ca,o ,,co#b4 ,! ammonia & c>bon dioxide evolv$ 9 ! latt] two reactions are us$ 9 ! prep>ation ( an additional quantity ( ammonium hydrog5 c>bonate4 ,x w ?us be se5 t !re is no loss ( ammonia4 ,! only mat]ials p]man5tly us$ up are calcium c>bonate & salt1 :ile ! only wa/e product is calcium *loride4 ,hi/orical4 ,9 =m] times sodium c>bonate 0 made by burn+ seawe$s & extract+ ! c>bonate f _! a%4 ,on ?is acc\nt ! salt 0 call$ soda a%1 & ! "n is /ill 9 common use4 ,dur+ ! ,fr5* ,revolution ?is supply 0 cut (f1 & 9 behalf ( ! ,fr5* gov]nm5t ,le ,blanc made a /udy ( me?ods ( prep>+ ! c>bonate directly f salt4 ,z a result he devis$ ! me?od :i* be>s 8 "n1 & :i* 0 us$ exclusively = _m ye>s4 ,x has be5 replac$ to a l>ge ext5t by ! ,solvay process1 :i* has ! advantage t ! mat]ials us$ are inexp5sive1 & t ! ammonium hydrog5 c>bonate us$ c be reg5]at$ f ! products =m$ 9 ! process4 ,mu* exp5se is also sav$ 9 fuel1 & ! sodium hydrog5 c>bonate1 :i* is ! fir/ product ( ! process1 has itself _m comm]cial uses4 ,! ,le ,blanc process is /ill us$1 h[ev]1 s9ce ! hydro*loric acid g5]at$ is ( value4 ,by-products4 ,! sub/ances obta9$ 9 a giv5 process1 aside f ! ma9 product1 are call$ ! by-products4 ,! success ( _m processes dep5ds ^u ! value ( ! by-products =m$4 ,?us hydro*loric acid1 a by-product 9 ! ,le ,blanc process1 is valuable en\gh to make ! process pay1 ev5 ?\gh sodium c>bonate c be made *eap] 9 o!r ways4 ,prop]ties ( sodium c>bonate4 ,sodium c>bonate =ms l>ge cry/als ( ! =mula ,na#b;,,co#c #aj ,h#b,o4 ,x has a mild alkal9e reaction & is us$ = laundry purposes "u ! "n ( wa%+ soda4 ,m]e m5tion ( ! fact t x is us$ 9 ! manufacture ( glass1 soap1 & _m *emical reag5ts w indicate its importance 9 ! indu/ries4 ,x is "o ( ! few soluble c>bonates4 ,sodium hydrog5 c>bonate 7bic>bonate ( soda7 7,na,h,c,o#c74 ,?is salt1 commonly call$ bic>bonate ( soda1 or bak+ soda1 is made by ! ,solvay process1 z expla9$ above1 or by pass+ c>bon dioxide into /rong solutions ( sodium c>bonate3 ,na#b;,,co#c ,h#b,o ,,co#b #b,na,h,c,o#c4 ,! bic>bonate1 be+ sp>+ly soluble1 cry/allizes out4 ,a mixture ( ! bic>bonate ) "s sub/ance 7! comp\nd kn[n z cream ( t>t> is g5]ally us$7 :i* sl[ly reacts ) x1 lib]at+ c>bon dioxide1 is us$ l>gely 9 bak+4 ,! c>bon dioxide g5]at$ =ces its way ?r\gh ! d\gh1 ?us mak+ x por\s & light4 ,sodium nitrate 7,*ili saltpet]7 7,na,n,o#c74 ,?is sub/ance is f\nd 9 nature 9 arid regions 9 a numb] ( places1 :]e x has be5 =m$ app>5tly by ! decay ( organic sub/ances 9 ! pres5ce ( air & sodium salts4 ,! l>ge/ deposits are 9 ,*ili1 & mo/ ( ! nitrate ( comm]ce comes f t c\ntry4 ,small] deposits occur 9 ,cali=nia & ,nevada4 ,! comm]cial salt is prep>$ by dissolv+ ! crude nitrate 9 wat]1 all[+ ! insoluble e>?y mat]ials to settle1 & evaporat+ ! cle> solution s obta9$ to cry/allization4 ,! soluble impurities rema9 = ! mo/ "p 9 ! "m liquors4 ,s9ce ?is salt is ! only nitrate f\nd ext5sively 9 nature1 x is ! mat]ial f :i* o!r nitrates z well z nitric acid are prep>$4 ,x is us$ 9 enorm\s quantities 9 ! manufacture ( sulphuric acid & potassium nitrate1 & z a f]tiliz]4 ,sodium phosphate 7,na#b;,,hpo#dab;,h#b,o74 ,s9ce phosphoric acid has ?ree replaceable hydrog5 atoms1 ?ree sodium phosphates are possible1--two acid salts & "o normal4 ,all ?ree c be made )\t difficulty1 b disodium phosphate is ! only "o :i* is l>gely us$1 & is ! salt :i* is commonly call$ sodium phosphate4 ,x is made by ! action ( phosphoric acid on sodium c>bonate3 ,na#b;,,co#c ,h#c,,po#d ,na#b;,,hpo#d ,,co#b ,h#b,o4 ,x is int]e/+ z be+ "o ( ! few phosphates :i* are soluble 9 wat]1 & is ! salt commonly us$ :5 a soluble phosphate is ne$$4 ,normal sodium phosphate 7,na#c,,po#d74 ,al?\gh ?is is a normal salt its solution has a /rongly alkal9e reaction4 ,?is is due to ! fact t ! salt hydrolyzes 9 solution into sodium hydroxide & disodium phosphate1 z repres5t$ 9 ! equation ,na#c,,po#d ,h#b,o ,na#b;,,hpo#d ,na,o,h4 ,sodium hydroxide is /rongly alkal9e1 :ile disodium phosphate is ne>ly neutral 9 reaction4 ,! solution z a :ole is !re=e alkal9e4 ,! salt is prep>$ by add+ a l>ge excess ( sodium hydroxide to a solution ( disodium phosphate & evaporat+ to cry/allization4 ,! excess ( ! sodium hydroxide rev]ses ! reaction ( hydrolysis & ! normal salt cry/allizes out4 ,sodium tetraborate 7borax7 7,na#b;,b#d,o#gaj;,h#b,o74 ,! prop]ties ( ?is important comp\nd h be5 discuss$ "u ! head ( boron4 ,,potassium ,occurr5ce 9 nature4 ,potassium is a con/itu5t ( _m common rocks & m9]als1 & is !re=e a r abundant elem5t1 ?\gh n s abundant z sodium4 ,feldsp>1 :i* occurs bo? by itself & z a con/itu5t ( granite1 conta9s consid]able potassium4 ,! elem5t is a con/itu5t ( all clay & ( mica & also occurs 9 v l>ge deposits at ,/assfurt1 ,g]many1 9 ! =m ( ! *loride & sulphate1 associat$ ) comp\nds ( sodium & magnesium4 ,9 small quantities x is f\nd z nitrate & 9 _m o!r =ms4 ,! natural decomposition ( rocks conta9+ potassium gives rise to v>i\s comp\nds ( ! elem5t 9 all f]tile soils4 ,its soluble comp\nds are absorb$ by gr[+ plants & built up into complex vegetable sub/ances2 :5 ^! are burn$ ! potassium rema9s 9 ! a% 9 ! =m ( ! c>bonate4 ,crude c>bonate obta9$ f wood a%es 0 =m]ly ! *ief s\rce ( potassium comp\nds2 !y are n[ mo/ly prep>$ f ! salts ( ! ,/assfurt deposits4 ,/assfurt salts4 ,^! salts =m v ext5sive deposits 9 middle & nor? ,g]many1 ! mo/ not$ locality = work+ !m be+ at ,/assfurt4 ,! deposits are v ?ick & re/ ^u an enorm\s lay] ( common salt4 ,!y are 9 ! =m ( a s]ies ( /rata1 ea* consi/+ l>gely ( a s+le m9]al salt4 ,a cross section ( ^! deposits is %[n 9 ,fig4 #gh4 ,:ile ^! /rata are salts f a *emical /&po9t1 !y are z solid & h>d z _m k9ds ( /one1 & are m9$ z /one or coal w\ld be4 ,s9ce ! /rata diff] 9 g5]al appe>ance1 ea* c be m9$ sep>ately1 & ! v>i\s m9]als c be work$ up by me?ods adapt$ to ea* p>ticul> case4 ,! *ief m9]als ( comm]cial importance 9 ^! deposits are ! foll[+3 ,sylv9e ,k,cl4 ,anhydrite ,ca,s,o#d4 ,c>nallite ,k,cl,mg,cl#bf;,h#b,o4 ,ka9ite ,k#b,,s#d,mg,s,o#d,mg,cl#bf;,h#b,o4 ,polyhalite ,k#b,,s#d,mg,s,o#db;,ca,s,o#db;,h#b,o4 ,kies]ite ,mg,s,o#d;,h#b,o4 ,s*nite ,k#b,,s#d,mg,s,o#df;,h#b,o4 ,prep>ation & prop]ties4 ,! metal is prep>$ by ! same me?od us$ 9 ! prep>ation ( sodium4 ,9 mo/ respects x is v simil> to sodium1 ! *ief diff]5ce be+ t x is ev5 m en]getic 9 its action ^u o!r sub/ances4 ,! fre%ly cut1 bright surface in/antly becomes dim ?r\gh oxidation by ! air4 ,x decomposes wat] v vigor\sly1 ! heat ( reaction be+ suffici5t to ignite ! hydrog5 evolv$4 ,x is some:at light] ?an sodium & is pres]v$ "u gasol9e4 ,illu/ration3 ,fig4 #gh ,potassium hydroxide 7cau/ic pota%7 7,,koh74 ,potassium hydroxide is prep>$ by me?ods exactly simil> to ^? us$ 9 ! prep>ation ( sodium hydroxide1 :i* comp\nd x closely resembles 9 bo? physical & *emical prop]ties4 ,x is n us$ to any v great ext5t1 be+ replac$ by ! *eap] sodium hydroxide4 ,action ( ! halog5 elem5ts on potassium hydroxide4 ,:5 any "o ( ! ?ree halog5 elem5ts--*lor9e1 brom9e1 & iod9e--is add$ to a solution ( potassium hydroxide a reaction takes place1 ! nature ( :i* dep5ds ^u ! conditions ( ! exp]im5t4 ,?us1 :5 *lor9e is pass$ into a cold dilute solution ( potassium hydroxide ! reaction express$ by ! foll[+ equation takes place3 7#a7 #b,,koh #b;,cl ,k,cl ,k,cl,o ,h#b,o4 ,if ! solution ( hydroxide is conc5trat$ & hot1 on ! o!r h&1 ! potassium hypo*lorite =m$ accord+ to equation 7#a7 breaks d[n z fa/ z =m$3 7#b7 #c,k,cl,o ,k,cl,o#c #b,k,cl4 ,equation 7#a71 aft] be+ multipli$ by #c1 may be comb9$ ) equation 7#b71 giv+ ! foll[+3 7#c7 #f,,koh #f;,cl #e,k,cl ,k,cl,o#c #c;,h#b,o4 ,?is repres5ts 9 a s+le equation ! action ( *lor9e on hot1 conc5trat$ solutions ( potassium hydroxide4 ,by means ( ^! reactions "o c prep>e potassium *loride1 potassium hypo*lorite1 & potassium *lorate4 ,by sub/itut+ brom9e or iod9e = *lor9e ! correspond+ comp\nds ( ^! elem5ts are obta9$4 ,"s ( ^! comp\nds c be obta9$ 9 *eap] ways4 ,if ! halog5 elem5t is add$ to a solution ( sodium hydroxide or calcium hydroxide1 ! reaction :i* takes place is exactly simil> to t :i* takes place ) potassium hydroxide4 ,x is possible1 !re=e1 to prep>e 9 ?is way ! sodium & calcium comp\nds correspond+ to ! potassium comp\nds giv5 above4 ,potassium *loride 7,k,cl74 ,?is salt occurs 9 nature 9 sea wat]1 9 ! m9]al sylv9e1 &1 comb9$ ) magnesium *loride1 z c>nallite 7,k,cl,mg,cl#bf;,h#b,o74 ,x is prep>$ f c>nallite by saturat+ boil+ wat] ) ! m9]al & all[+ ! solution to cool4 ,! m9]al decomposes :ile 9 solution1 & ! potassium *loride cry/allizes out on cool+1 :ile ! v soluble magnesium *loride rema9s 9 solution4 ,! salt is v simil> to sodium *loride bo? 9 physical & *emical prop]ties4 ,x is us$ 9 ! prep>ation ( ne>ly all o!r potassium salts1 &1 toge!r ) potassium sulphate1 is us$ z a f]tiliz]4 ,potassium bromide 7,k,br74 ,:5 brom9e is add$ to a hot conc5trat$ solution ( potassium hydroxide !re is =m$ a mixture ( potassium bromide & potassium bromate 9 accordance ) ! reactions already discuss$4 ,!re is no special use = ! bromate1 s ! solution is evaporat$ to dryness1 & ! residue1 consi/+ ( a mixture ( ! bromate & bromide1 is /rongly heat$4 ,?is *anges ! bromate to bromide1 z foll[s3 ,k,br,o#c ,k,br #c,o4 ,! bromide is !n cry/alliz$ f wat]1 =m+ l>ge colorless cry/als4 ,x is us$ 9 m$ic9e & 9 photography4 ,potassium iodide 7,,ki74 ,potassium iodide may be made by exactly ! same me?od z has j be5 describ$ = ! bromide1 sub/itut+ iod9e = brom9e4 ,x is m frequ5tly made z foll[s4 ,iron fil+s are treat$ ) iod9e1 =m+ ! comp\nd ,fe#c;,i#h2 on boil+ ?is sub/ance ) potassium c>bonate ! reaction repres5t$ 9 ! foll[+ equation occurs3 ,fe#c;,i#h #d,k#b;,,co#c ,fe#c,o#d #h,,ki #d;,,co#b4 ,potassium iodide f9ds its *ief use 9 m$ic9e4 ,potassium *lorate 7,k,cl,o#c74 ,?is salt1 z has j be5 expla9$1 c be made by ! action ( *lor9e on /rong potassium hydroxide solutions4 ,! *ief use ( potassium *lorate is z an oxidiz+ ag5t 9 ! manufacture ( mat*es1 fireworks1 & explosives2 x is also us$ 9 ! prep>ation ( oxyg5 & 9 m$ic9e4 ,comm]cial prep>ation4 ,by ref]r+ to ! reaction betwe5 *lor9e & hot conc5trat$ solutions ( potassium hydroxide1 x w be se5 t only "o molecule ( potassium *lorate is =m$ f six molecules ( potassium hydroxide4 ,p>tly because ( ?is poor yield & p>tly because ! potassium hydroxide is r exp5sive1 ?is process is n an economical "o = ! prep>ation ( potassium *lorate4 ,! comm]cial me?od is ! foll[+4 ,*lor9e is pass$ into hot solutions ( calcium hydroxide1 a comp\nd :i* is v *eap4 ,! result+ calcium *loride & *lorate are bo? v soluble4 ,to ! solution ( ^! salts potassium *loride is add$1 & z ! solution cools ! sp>+ly soluble potassium *lorate cry/allizes out3 ,ca7,cl,o#c7b #b,k,cl #b,k,cl,o#c ,ca,cl#b4 ,electro-*emical processes are also us$4 ,potassium nitrate 7saltpet]7 7,,kno#c74 ,?is salt 0 =m]ly made by all[+ animal refuse to decompose 9 ! op5 air 9 ! pres5ce ( wood a%es or e>?y mat]ials conta9+ potassium4 ,"u ^! conditions ! nitrog5 9 ! organic matt] is 9 "p conv]t$ into potassium nitrate1 :i* 0 obta9$ by extract+ ! mass ) wat] & evaporat+ to cry/allization4 ,?is crude & sl[ process is n[ almo/ entirely replac$ by a manufactur+ process 9 :i* ! potassium salt is made f ,*ili saltpet]3 ,na,n,o#c ,k,cl ,na,cl ,,kno#c4 ,?is process has be5 made possible by ! discov]y ( ! ,*ili nit] b$s & ! potassium *loride ( ! ,/assfurt deposits4 ,! reaction dep5ds = its success ^u ! app>5tly insignificant fact t sodium *loride is almo/ equally soluble 9 cold & hot wat]4 ,all f\r factors 9 ! equation are r soluble 9 cold wat]1 b 9 hot wat] sodium *loride is f> less soluble ?an ! o!r ?ree4 ,:5 hot saturat$ solutions ( sodium nitrate & potassium *loride are br\ght toge!r1 sodium *loride precipitates & c be filt]$ (f1 leav+ potassium nitrate 9 solution1 toge!r ) "s sodium *loride4 ,on cool+1 potassium nitrate cry/allizes out1 leav+ small am\nts ( ! o!r salts 9 solution4 ,potassium nitrate is a colorless salt :i* =ms v l>ge cry/als4 ,x is /able 9 ! air1 & :5 heat$ is a good oxidiz+ ag5t1 giv+ up oxyg5 q readily4 ,its *ief use is 9 ! manufacture ( gunp[d]4 ,gunp[d]4 ,! object s\ght = 9 ! prep>ation ( gunp[d] is to secure a solid sub/ance :i* w rema9 un*ang$ "u ord9>y conditions1 b :i* w explode readily :5 ignit$1 evolv+ a l>ge volume ( gas4 ,:5 a mixture ( c>bon & potassium nitrate is ignit$ a great deal ( gas is =m$1 z w be se5 f ! equation #b,,kno#c #c;,c ,,co#b ,,co ,n#b ,k#b;,,co#c4 ,by add+ sulphur to ! mixture ! volume ( gas =m$ 9 ! explosion is consid]ably increas$3 #b,,kno#c #c;,c ,s #c;,,co#b ,n#b ,k#b,s4 ,gunp[d] is simply a me*anical mixture ( ^! ?ree sub/ances 9 ! proportion requir$ = ! above reaction4 ,:ile ! equation repres5ts ! pr9cipal reaction1 o!r reactions also take place4 ,! gases =m$ 9 ! explosion1 :5 measur$ "u /&>d conditions1 occupy ab\t two hundr$ & eighty times ! volume ( ! orig9al p[d]4 ,potassium sulphide 7,k#b,s7 is a solid sub/ance1 & x is l>gely due to x t gunp[d] gives (f smoke & soot :5 x explodes4 ,smokeless p[d] consi/s ( organic sub/ances :i*1 on explosion1 give only colorless gases1 & h5ce produce no smoke4 ,sodium nitrate is *eap] ?an potassium nitrate1 b x is n adapt$ to ! manufacture ( ! be/ grades ( p[d]1 s9ce x is some:at deliquesc5t & does n give up its oxyg5 s readily z does potassium nitrate4 ,x is us$1 h[ev]1 9 ! *eap] grades ( p[d]1 su* z are employ$ = bla/+4 ,potassium cyanide 7,,kcn74 ,:5 animal matt] conta9+ nitrog5 is heat$ ) iron & potassium c>bonate1 complicat$ *anges occur :i* result 9 ! =mation ( a sub/ance commonly call$ yell[ prussiate ( pota%1 :i* has ! =mula ,k#d;,fe,c#f,n#f4 ,:5 ?is sub/ance is heat$ ) potassium1 potassium cyanide is =m$3 ,k#d;,fe,c#f,n#f #b ,k #f,,kcn ,fe4 ,s9ce sodium is mu* *eap] ?an potassium x is (t5 us$ 9 place ( x3 ,k#d;,fe,c#f,n#f #b,na #d,,kcn #b,na,c,n ,fe4 ,! mixture ( cyanides s result+ s]ves mo/ ( ! purposes ( ! pure salt4 ,x is us$ v ext5sively 9 sev]al metallurgical processes1 p>ticul>ly 9 ! extraction ( gold4 ,potassium cyanide is a :ite solid *>act]iz$ by its poison\s prop]ties1 & mu/ be us$ ) extreme caution4 ,potassium c>bonate 7pota%7 7,k#b;,,co#c74 ,?is comp\nd occurs 9 wood a%es 9 small quantities4 ,x _c be prep>$ by ! ,solvay process1 s9ce ! acid c>bonate is q soluble 9 wat]1 b is made by ! ,le ,blanc process4 ,its *ief use is 9 ! manufacture ( o!r potassium salts4 ,o!r salts ( potassium4 ,among ! o!r salts ( potassium frequ5tly met ) are ! sulphate 7,k#b,,s#d71 ! acid c>bonate 7,,khco#c71 ! acid sulphate 7,,khso#d71 & ! acid sulphite 7,,khso#c74 ,^! are all :ite solids4 ,,li?ium1 ,,rubidium1 ,c,,sium ,( ! ?ree rema9+ elem5ts ( ! family--li?ium1 rubidium1 & csium--li?ium is by f> ! mo/ common1 ! o!r two be+ v r>e4 ,li?ium *loride & c>bonate are n infrequ5tly f\nd 9 natural m9]al wat]s1 & z ^! sub/ances are suppos$ to increase ! m$ic9al value ( ! wat]1 !y are v (t5 add$ to artificial m9]al wat]s 9 small quantities4 ,,comp\nds ,,( ,,ammonium ,g5]al4 ,z expla9$ 9 a previ\s *apt]1 :5 ammonia is pass$ into wat] ! two comp\nds comb9e to =m ! base ,,nh#d,,oh1 kn[n z ammonium hydroxide4 ,:5 ?is base is neutraliz$ ) acids !re are =m$ ! correspond+ salts1 kn[n z ! ammonium salts4 ,s9ce ! ammonium gr\p is unival5t1 ammonium salts resemble ^? ( ! alkali metals 9 =mulas2 !y also resemble ! latt] salts v mu* 9 _! *emical prop]ties1 & may be conv5i5tly describ$ 9 connection ) !m4 ,among ! ammonium salts ! *loride1 sulphate1 c>bonate1 & sulphide are ! mo/ famili>4 ,ammonium *loride 7sal ammoniac7 7,,nh#d;,cl74 ,?is sub/ance is obta9$ by neutraliz+ ammonium hydroxide ) hydro*loric acid4 ,x is a colorless sub/ance cry/alliz+ 9 f9e ne$les1 &1 l mo/ ammonium salts1 is v soluble 9 wat]4 ,:5 plac$ 9 a tube & heat$ /rongly x decomposes into hydro*loric acid & ammonia4 ,:5 ^! gases rea* a cool] portion ( ! tube !y at once recomb9e1 & ! result+ ammonium *loride is deposit$ on ! sides ( ! tube4 ,9 ?is way ! salt c be sep>at$ f nonvolatile impurities4 ,ammonium *loride is sometimes us$ 9 prep>ation ( ammonia2 x is also us$ 9 mak+ dry batt]ies & 9 ! laboratory z a *emical reag5t4 ,ammonium sulphate 77,,nh#d7b,,s#d74 ,?is salt resembles ! *loride v closely1 &1 be+ *eap]1 is us$ 9 place ( x :5 possible4 ,x is us$ 9 l>ge quantity z a f]tiliz]1 ! nitrog5 :i* x conta9s be+ a v valuable food = plants4 ,ammonium c>bonate 77,,nh#d7b;,,co#c74 ,?is salt1 z well z ! acid c>bonate 7,,nh#d;,,hco#c71 is us$ z a *emical reag5t4 ,!y are colorless solids1 freely soluble 9 wat]4 ,! normal c>bonate is made by heat+ ammonium *loride ) p[d]$ lime/one 7calcium c>bonate71 ! ammonium c>bonate be+ obta9$ z a sublimate 9 compact h>d masses3 #b,,nh#d;,cl ,ca,c,o#c 7,,nh#d7b;,,co#c ,ca,cl#b4 ,! salt always smells ( ammonia1 s9ce x sl[ly decomposes1 z %[n 9 ! equation 7,,nh#d7b;,,co#c ,,nh#d;,,hco#c ,,nh#c4 ,! acid c>bonate1 or bic>bonate1 is prep>$ by saturat+ a solution ( ammonium hydroxide ) c>bon dioxide3 ,,nh#d,,oh ,,co#b ,,nh#d;,,hco#c4 ,x is a well-cry/alliz$ /able sub/ance4 ,ammonium sulphide 77,,nh#d7b,s74 ,ammonium sulphide is prep>$ by ! action ( hydrosulphuric acid ^u ammonium hydroxide3 #b,,nh#d,,oh ,h#b,s 7,,nh#d7b,s #b;,h#b,o4 ,if ! action is all[$ to cont9ue until no m hydrosulphuric acid is absorb$1 ! product is ! acid sulphide1 sometimes call$ ! hydrosulphide3 ,,nh#d,,oh ,h#b,s ,,nh#d;,,hs ,h#b,o4 ,if equal am\nts ( ammonium hydroxide & ammonium acid sulphide are br\ght toge!r1 ! normal sulphide is =m$3 ,,nh#d,,oh ,,nh#d;,,hs 7,,nh#d7b,s ,h#b,o ,x has be5 obta9$ 9 ! solid /ate1 b only ) great difficulty4 ,z us$ 9 ! laboratory x is always 9 ! =m ( a solution4 ,x is mu* us$ 9 ! process ( *emical analysis because x is a soluble sulphide & easily prep>$4 ,on exposure to ! air ammonium sulphide sl[ly decomposes1 be+ conv]t$ into ammonia1 wat]1 & sulphur3 7,,nh#d7b,s ,o #b,,nh#c ,h#b,o ,s4 ,z fa/ z ! sulphur is lib]at$ x comb9es ) ! un*ang$ sulphide to =m sev]al diff]5t ammonium sulphides 9 :i* !re are f two to five sulphur atoms 9 ! molecule1 ?us3 7,,nh#d7b,s#b1 7,,nh#d7b,s#c1 7,,nh#d7b,s#e4 ,^! sulphides 9 turn decompose by fur!r action ( oxyg51 s t ! f9al products ( ! reaction are ^? giv5 9 ! equation4 ,a solution ( ^! comp\nds is yell[ & is sometimes call$ yell[ ammonium sulphide4 ,,flame ,,reaction--,,spectroscope ,:5 comp\nds ( ei!r sodium or potassium are br\ght into ! non-lum9\s flame ( a ,buns5 burn] ! flame becomes color$4 ,sodium comp\nds color x int5sely yell[1 :ile ^? ( potassium color x pale violet4 ,:5 only "o ( ^! elem5ts is pres5t x is easy to id5tify x by ?is simple te/1 b :5 bo? are pres5t ! int5se color ( ! sodium flame entirely conceals ! pale t9t *>act]i/ic ( potassium comp\nds4 ,x is possible to detect ! potassium flame 9 su* cases1 h[ev]1 9 ! foll[+ way4 ,:5 light is all[$ to %9e ?r\gh a v small hole or slit 9 "s k9d ( a scre51 su* z a piece ( metal1 ^u a triangul> prism ( glass1 ! light is b5t or refract$ out ( its c\rse in/ead ( pass+ /raight ?r\gh ! glass4 ,x ?us comes out ( ! prism at "s angle to ! l9e at :i* x ent]$4 ,yell[ light is b5t m ?an r$1 & violet m ?an yell[4 ,:5 light made up ( ! yell[ ( sodium & ! violet ( potassium %9es ?r\gh a slit ^u su* a prism1 ! yell[ & ! violet lights come out at some:at diff]5t angles1 & s two color$ l9es ( light--a yell[ l9e & a violet l9e--are se5 on look+ into ! prism 9 ! prop] direction4 ,! in/rum5t us$ = sep>at+ ! rays ( light 9 ?is way is call$ a spectroscope 7,fig4 #gi74 ,! mat]ial to be te/$ is plac$ on a plat9um wire & held 9 ! colorless ,buns5 flame4 ,! result+ light passes ?r\gh ! slit 9 ! end ( tube ,b1 & !n ?r\gh ,b to ! prism4 ,! result+ l9es ( light are se5 by look+ into ! tube ,a1 :i* conta9s a magnify+ l5s4 ,mo/ elem5ts give m ?an "o image ( ! slit1 ea* hav+ a diff]5t color1 & ! s]ies ( color$ l9es due to an elem5t is call$ its spectrum4 ,illu/ration3 ,fig4 #gi ,! spectra ( ! kn[n elem5ts h be5 c>efully /udi$1 & any elem5t :i* imp>ts a *>act]i/ic color to a flame1 or has a spectrum ( its own1 c be id5tifi$ ev5 :5 o!r elem5ts are pres5t4 ,?r\gh ! spectroscopic exam9ation ( c]ta9 m9]als a numb] ( elem5ts h be5 discov]$ by ! obs]vation ( l9es :i* did n belong to any kn[n elem5t4 ,a /udy ( ! sub/ance !n br\ght to light ! new elem5t4 ,rubidium & csium 7 discov]$ 9 ?is way1 rubidium hav+ bright r$ l9es & csium a v int5se blue l9e4 ,li?ium colors ! flame deep r$1 & has a bright r$ l9e 9 its spectrum4 ,,ex]cises #a4 ,:at is an alkali8 ,c a metal itself be an alkali8 #b4 ,write equations %[+ h[ ! foll[+ *anges may be br\ght ab\t1 giv+ ! g5]al pr9ciple involv$ 9 ea* *ange3 ,na,cl -- ,na#b,,s#c1 ,na#b,,s#c -- ,na,cl1 ,na,cl -- ,na,br1 ,na#b,,s#d -- ,na,n,o#c1 ,na,n,o#c -- ,na,h,c,o#c4 #c4 ,:at c>bonates are soluble8 #d4 ,/ate ! conditions "u :i* ! reaction repres5t$ by ! foll[+ equation c be made to g 9 ei!r direction3 ,na#b;,,co#c ,h#b,o ,,co#b -- #b ,na,h,c,o#c4 #e4 ,acc\nt = ! fact t solutions ( sodium c>bonate & potassium c>bonate are alkal9e4 #f4 ,:at non-metallic elem5t is obta9$ f ! deposits ( ,*ili saltpet]8 #g4 ,suppos+ conc5trat$ hydro*loric acid 7d54 #a4b7 to be wor? six c5ts a p\nd1 :at is ! value ( ! acid g5]at$ 9 ! prep>ation ( #a ton ( sodium c>bonate by ! ,le ,blanc process8 #h4 ,:at weight ( sodium c>bonate cry/als w #a kg4 ( ! anhydr\s salt yield8 #i4 ,write equations = ! prep>ation ( potassium hydroxide by ?ree diff]5t me?ods4 #aj4 ,:at w\ld take place if a bit ( potassium hydroxide 7 left expos$ to ! air8 #aa4 ,write ! equations = ! reactions betwe5 sodium hydroxide & brom9e2 betwe5 potassium hydroxide & iod9e4 #ab4 ,write equations = ! prep>ation ( potassium sulphate2 ( potassium acid c>bonate4 #ac4 ,:at weight ( c>nallite w\ld be necess>y 9 ! prep>ation ( #a ton ( potassium c>bonate8 #ad4 ,write ! equations %[+ h[ ammonium *loride1 ammonium sulphate1 ammonium c>bonate1 & ammonium nitrate may be prep>$ f ammonium hydroxide4 #ae4 ,write an equation to repres5t ! reaction involv$ 9 ! prep>ation ( ammonia f ammonium *loride4 #af4 ,:at sub/ances already /udi$ are prep>$ f ! foll[+ comp\nds8 ammonium *loride2 ammonium nitrate2 ammonium nitrite2 sodium nitrate2 sodium *loride4 #ag4 ,h[ c\ld y prove t ! wat] 9 cry/als ( common salt is n wat] ( cry/allization8 #ah4 ,h[ c\ld y di/+ui% betwe5 potassium *loride & potassium iodide8 betwe5 sodium *loride & ammonium *loride8 betwe5 sodium nitrate & potassium nitrate8 ,illu/ration3 ,,rob]t ,,wilhelm ,,buns5 7,g]man7 7#ahaa-ahii7 ,inv5t$ _m lecture-room & laboratory appliances 7,buns5 burn]72 inv5t$ ! spectroscope & ) x discov]$ rubidium & csium2 greatly p]fect$ me?ods ( electrolysis1 inv5t+ a new batt]y2 made _m inve/igations among metallic & organic sub/ances ,,*apt] ,,xxiv ,,! ,,alkal9e-,,e>? ,,family ,,milligrams ,,sol- ,,uble ,,9 #a ,l4 ,,( ,,wat] ,,at #ah ,,symbol ,,atomic ,,d5sity ,,c>bonate ,,weight ,,decomposes ,,sulphate ,,hydrox- ,,ide ,calcium ,ca #dj4a #a4ed #bjgj4jj #afgj4 ,at dull r$ heat ,/rontium ,sr #hg4f #b4ej #agj4jj #gdfj4 ,at :ite heat ,b>ium ,ba #acg4d #c4ge #b4bi #cfcjj4 ,sc>cely at all ,! family4 ,! alkal9e-e>? family consi/s ( ! v abundant elem5t calcium & ! mu* r>] elem5ts /rontium & b>ium4 ,!y are call$ ! alkal9e-e>? metals because _! prop]ties are betwe5 ^? ( ! alkali metals & ! e>? metals4 ,! e>? metals w be discuss$ 9 a lat] *apt]4 ,! family is also frequ5tly call$ ! calcium family4 #a4 ,occurr5ce4 ,^! elem5ts d n occur free 9 nature4 ,_! mo/ abundant comp\nds are ! c>bonates & sulphates2 calcium also occurs 9 l>ge quantities z ! phosphate & silicate4 #b4 ,prep>ation4 ,! metals 7 fir/ prep>$ by ,davy 9 #ahjh by electrolysis4 ,?is me?od has aga9 come into use 9 rec5t ye>s4 ,/rontium & b>ium h z yet be5 obta9$ only 9 small quantities & 9 ! impure /ate1 & _m ( _! physical prop]ties1 su* z _! d5sities & melt+ po9ts1 are !re=e imp]fectly kn[n4 #c4 ,prop]ties4 ,! ?ree metals resemble ea* o!r v closely4 ,!y are silv]y-:ite 9 color & are ab\t z h>d z lead4 ,_! d5sities increase ) _! atomic weights1 z is %[n 9 ! table on opposite page4 ,l ! alkali metals !y h a /rong aff9ity = oxyg51 t>ni%+ 9 ! air ?r\gh oxidation4 ,!y decompose wat] at ord9>y temp]atures1 =m+ hydroxides & lib]at+ hydrog54 ,:5 ignit$ 9 ! air !y burn ) brilliancy1 =m+ oxides ( ! g5]al =mula ,,mo4 ,^! oxides readily comb9e ) wat]1 accord+ to ! equation ,,mo ,h#b,o ,m7,,oh7#b4 ,ea* ( ! elem5ts has a *>act]i/ic spectrum1 & ! pres5ce ( ! metals c easily be detect$ by ! spectroscope4 #d4 ,comp\nds4 ,! elem5ts are dival5t 9 almo/ all ( _! comp\nds1 & ^! comp\nds 9 solution give simple1 dival5t1 colorless ions4 ,! correspond+ salts ( ! ?ree elem5ts are v simil> to ea* o!r & %[ a regul> v>iation 9 prop]ties 9 pass+ f calcium to /rontium & f /rontium to b>ium4 ,?is is se5 9 ! solubility ( ! sulphate & hydroxide1 & 9 ! ease ( decomposition ( ! c>bonates1 z giv5 9 ! table4 ,unlike ! alkali metals1 _! normal c>bonates & phosphates are insoluble 9 wat]4 ,,calcium ,occurr5ce4 ,! comp\nds ( calcium are v abundant 9 nature1 s t ! total am\nt ( calcium 9 ! e>?'s cru/ is v l>ge4 ,a great _m diff]5t comp\nds conta9+ ! clem5t are kn[n1 ! mo/ important ( :i* are ! foll[+3 ,calcite 7m>ble7 ,ca,c,o#c4 ,phosphorite ,ca#c7,,po#d7b4 ,fluorsp> ,ca,f#b4 ,wolla/onite ,ca,si,o#c4 ,gypsum ,ca,s,o#db;,h#b,o4 ,anhydrite ,ca,s,o#d4 ,prep>ation4 ,calcium is n[ prep>$ by ! electrolysis ( ! melt$ *loride1 ! metal deposit+ 9 solid condition on ! ca?ode4 ,x is a gray metal1 consid]ably heavi] & h>d] ?an sodium4 ,x acts ^u wat]1 =m+ calcium hydroxide & hydrog51 b ! action does n evolve suffici5t heat to melt ! metal4 ,x promises to become a useful sub/ance1 ?\gh no comm]cial applications = x h z yet be5 f\nd4 ,calcium oxide 7lime1 quicklime7 7,ca,o74 ,lime is prep>$ by /rongly heat+ calcium c>bonate 7lime/one7 9 l>ge furnaces call$ kilns3 ,ca,c,o#c ,ca,o ,,co#b4 ,:5 pure1 lime is a :ite amorph\s sub/ance4 ,heat$ int5sely1 z 9 ! oxyhydrog5 flame1 x gives a brilliant light call$ ! lime light4 ,al?\gh x is a v difficultly fusible sub/ance1 yet 9 ! electric furnace x c be made to melt & ev5 boil4 ,wat] acts ^u lime ) ! evolution ( a great deal ( heat1--h5ce ! "n quicklime1 or live lime1--! process be+ call$ slak+4 ,! equation is ,ca,o ,h#b,o ,ca7,,oh7#b4 ,lime readily absorbs moi/ure f ! air1 & is us$ to dry moi/ gases1 especially ammonia1 :i* _c be dri$ by ! usual desiccat+ ag5ts4 ,x also absorbs c>bon dioxide1 =m+ ! c>bonate ,ca,o ,,co#b ,ca,c,o#c4 ,lime expos$ to air is !re=e gradually conv]t$ into hydroxide & c>bonate1 & w no long] slake ) wat]4 ,x is !n said to be air-slak$4 ,limekilns4 ,! old] kiln1 /ill 9 common use1 consi/s ( a l>ge cyl9drical /ack 9 :i* ! lime/one is loosely pack$4 ,a fire is built at ! base ( ! /ack1 & :5 ! burn+ is complete x is all[$ to die out & ! lime is remov$ f ! kiln4 ,! new] kilns are con/ruct$ z %[n 9 ,fig4 #hj4 ,a numb] ( fire boxes are built ar\nd ! l[] "p ( ! kiln1 "o ( :i* is %[n at ,b4 ,! fire is built on ! grate ,f & ! hot products ( combu/ion are drawn up ?r\gh ! /ack1 decompos+ ! lime/one4 ,! kiln is *>g$ at ,c1 & sometimes fuel is add$ ) ! lime/one to cause combu/ion ?r\gh\t ! cont5ts ( ! kiln4 ,! burn$ lime is rak$ out ?r\gh op5+s 9 ! bottom ( ! /ack1 "o ( :i* is %[n at ,d4 ,! advantage ( ?is k9d ( a kiln ov] ! old] =m is t ! process is cont9u\s1 lime/one be+ *>g$ 9 at ! top z fa/ z ! lime is remov$ at ! bottom4 ,illu/ration3 ,fig4 #hj ,calcium hydroxide 7slak$ lime7 7,ca7,,oh7#b74 ,pure calcium hydroxide is a light :ite p[d]4 ,x is sp>+ly soluble 9 wat]1 =m+ a solution call$ limewat]1 :i* is (t5 us$ 9 m$ic9e z a mild alkali4 ,*emically1 calcium hydroxide is a mod]ately /rong base1 ?\gh n s /rong z sodium hydroxide4 ,ow+ to its *eapness x is mu* us$ 9 ! indu/ries :5ev] an alkali is desir$4 ,a numb] ( its uses h already be5 m5tion$4 ,x is us$ 9 ! prep>ation ( ammonia1 blea*+ p[d]1 & potassium hydroxide4 ,x is also us$ to remove c>bon dioxide & sulphur comp\nds f coal gas1 to remove ! hair f hides 9 ! tann]ies 7?is recalls ! cau/ic or corrosive prop]ties ( sodium hydroxide71 & = mak+ mort>4 ,mort> is a mixture ( calcium hydroxide & s&4 ,:5 x is expos$ to ! air or spread ^u por\s mat]ials moi/ure is remov$ f x p>tly by absorption 9 ! por\s mat]ials & p>tly by evaporation1 & ! mort> becomes firm1 or sets4 ,at ! same "t c>bon dioxide is sl[ly absorb$ f ! air1 =m+ h>d calcium c>bonate3 ,ca7,,oh7#b ,,co#b ,ca,c,o#c ,h#b,o4 ,by ?is comb9$ action ! mort> becomes v h>d & adh]es firmly to ! surface ^u :i* x is spread4 ,! s& s]ves to give body to ! mort> & makes x por\s1 s t ! *ange into c>bonate c take place ?r\gh\t ! mass4 ,x also prev5ts too mu* %r9kage4 ,cem5t4 ,:5 lime/one to :i* clay & s& h be5 add$ 9 c]ta9 proportions is burn$ until x is p>tly fus$ 7"s natural m>l is already ( ab\t ! "r composition71 & ! cl9k] s produc$ is gr\nd to p[d]1 ! product is call$ cem5t4 ,:5 ?is mat]ial is moi/5$ x sets to a h>d /one-l mass :i* reta9s its h>dness ev5 :5 expos$ to ! cont9u$ action ( wat]4 ,x c be us$ = "u-wat] "w1 su* z bridge pi]s1 :]e mort> w\ld quickly s(t54 ,sev]al v>ieties ( cem5t are made1 ! be/ kn[n ( :i* is ,portl& cem5t4 ,gr[+ importance ( cem5t4 ,cem5t is rapidly com+ into use = a great v>iety ( purposes4 ,x is (t5 us$ 9 place ( mort> 9 ! con/ruction ( brick build+s4 ,mix$ ) cru%$ /one & s& x =ms concrete :i* is us$ 9 f\ndation "w4 ,x is also us$ 9 mak+ artificial /one1 t]ra-cotta trimm+s = build+s1 artificial /one walks & floors1 & ! l4 ,x is be+ us$ m & m = mak+ _m articles :i* 7 =m]ly made ( wood or /one1 & ! entire walls ( build+s are sometimes made ( cem5t blocks or ( concrete4 ,calcium c>bonate 7,ca,c,o#c74 ,?is sub/ance is f\nd 9 a great _m natural =ms to :i* v>i\s names h be5 giv54 ,!y may be classifi$ "u ?ree heads3 #a4 ,amorph\s c>bonate4 ,?is includes ^? =ms :i* are n m>k$ly cry/all9e4 ,lime/one is ! mo/ famili> ( ^! & is a grayi% rock usually f\nd 9 h>d /ratifi$ masses4 ,:ole m\nta9 ranges are sometimes made up ( ?is mat]ial4 ,x is always impure1 usually conta9+ magnesium c>bonate1 clay1 silica1 iron & alum9ium comp\nds1 & frequ5tly fossil rema9s4 ,m>l is a mixture ( lime/one & clay4 ,pe>ls1 *alk1 coral1 & %ells are l>gely calcium c>bonate4 #b4 ,hexagonal c>bonate4 ,calcium c>bonate cry/allizes 9 ! =m ( rhomb-%ap$ cry/als :i* belong to ! hexagonal sy/em4 ,:5 v pure & transp>5t ! sub/ance is call$ ,icel& sp>4 ,calcite is a simil> =m1 b some:at opaque or cl\d$4 ,mexican onyx is a massive v>iety1 /reak$ or b&$ ) colors due to impurities4 ,m>ble :5 pure is made up ( m9ute calcite cry/als4 ,/alactites & /alagmites are icicle-l =ms sometimes f\nd 9 caves4 #c4 ,rhombic c>bonate4 ,calcium c>bonate sometimes cry/allizes 9 ne$le-%ap$ cry/als belong+ to ! rhombic sy/em4 ,?is is ! un/able =m & t5ds to g ov] into ! o!r v>iety4 ,aragonite is ! mo/ famili> example ( ?is =m4 ,prep>ation & uses ( calcium c>bonate4 ,9 ! laboratory pure calcium c>bonate c be prep>$ by treat+ a soluble calcium salt ) a soluble c>bonate3 ,na#b;,,co#c ,ca,cl#b ,ca,c,o#c #b,na,cl4 ,:5 prep>$ 9 ?is way x is a s(t :ite p[d] (t5 call$ precipitat$ *alk1 & is mu* us$ z a poli%+ p[d]4 ,x is insoluble 9 wat]1 b dissolves 9 wat] saturat$ ) c>bon dioxide1 ow+ to ! =mation ( ! acid calcium c>bonate :i* is slightly soluble3 ,ca,c,o#c ,h#b;,,co#c ,ca7,,hco#c7b4 ,! natural v>ieties ( calcium c>bonate f9d _m uses1 su* z 9 ! prep>ation ( lime & c>bon dioxide2 9 metallurgical op]ations1 especially 9 ! bla/ furnaces2 9 ! manufacture ( soda1 glass1 & crayon 7:i*1 9 addition to *alk1 usually conta9s clay & calcium sulphate72 = build+ /one & balla/ = roads4 ,calcium *loride 7,ca,cl#b74 ,?is salt occurs 9 consid]able quantity 9 sea wat]4 ,x is obta9$ z a by-product 9 _m te*nical processes1 z 9 ! ,solvay soda process4 ,:5 cry/alliz$ f its saturat$ solutions x =ms colorless ne$les ( ! composition ,ca,cl#bf;,h#b,o4 ,by evaporat+ a solution to dryness & heat+ to a mod]ate temp]ature calcium *loride is obta9$ anhydr\s z a :ite por\s mass4 ,9 ?is condition x absorbs wat] ) great en]gy & is a valuable dry+ ag5t4 ,blea*+ p[d] 7,ca,o,cl#b74 ,:5 *lor9e acts ^u a solution ( calcium hydroxide ! reaction is simil> to t :i* occurs betwe5 *lor9e & potassium hydroxide3 #b ,ca7,,oh7#b #d ,cl ,ca,cl#b ,ca7,cl,o7#b #b ,h#b,o4 ,if1 h[ev]1 *lor9e is conduct$ ov] calcium hydroxide 9 ! =m ( a dry p[d]1 x is absorb$ & a sub/ance is =m$ :i* appe>s to h ! composition repres5t$ 9 ! =mula ,ca,o,cl#b4 ,?is sub/ance is call$ blea*+ p[d]1 or hypo*lorite ( lime4 ,x is probably ! calcium salt ( bo? hydro*loric & hypo*lor\s acids1 s t its /ructure is repres5t$ by ! =mula _/,cl,o ,ca ,cl4 ,9 solution ?is sub/ance acts exactly l a mixture ( calcium *loride 7,ca,cl#b7 & calcium hypo*lorite 7,ca7,cl,o7#b71 s9ce x dissociates to =m ! ions ,ca1 ,cl-1 & ,cl,o-4 ,blea*+ p[d] und]goes a numb] ( reactions :i* make x an important sub/ance4 #a4 ,:5 treat$ ) an acid x evolves *lor9e3 _/,cl,o ,ca ,h#b,,s#d ,ca,s,o#d ,h,cl ,h,cl,o1 ,cl ,h,cl ,h,cl,o ,h#b,o #b;,cl4 ,?is reaction c be employ$ 9 ! prep>ation ( *lor9e1 or ! nasc5t *lor9e may be us$ z a blea*+ ag5t4 #b4 ,x is sl[ly decompos$ by ! c>bon dioxide ( ! air1 yield+ calcium c>bonate & *lor9e3 ,ca,o,cl#b ,,co#b ,ca,c,o#c #b;,cl4 ,ow+ to ?is sl[ action ! sub/ance is a good dis9fectant4 #c4 ,:5 its solution is boil$ ! sub/ance breaks d[n into calcium *loride & *lorate3 #f;,ca,o,cl#b #e;,ca,cl#b ,ca7,cl,o#c7b4 ,?is reaction is us$ 9 ! prep>ation ( potassium *lorate4 ,calcium fluoride 7fluorsp>7 7,ca,f#b74 ,fluorsp> has already be5 m5tion$ z ! *ief natural comp\nd ( fluor9e4 ,x is f\nd 9 l>ge quantities 9 a numb] ( localities1 & is (t5 cry/alliz$ 9 p]fect cubes ( a light gre5 or ame?y/ color4 ,x c be melt$ easily 9 a furnace1 & is sometimes us$ 9 ! fus$ condition 9 metallurgical op]ations to protect a metal f ! action ( ! air dur+ its r$uction4 ,x is us$ z ! *ief s\rce ( fluor9e comp\nds1 especially hydr(luoric acid4 ,calcium sulphate 7gypsum7 7,ca,s,o#db;,h#b,o74 ,?is abundant sub/ance occurs 9 v p]fectly =m$ cry/als or 9 massive deposits4 ,x is (t5 f\nd 9 solution 9 natural wat]s & 9 ! sea wat]4 ,salts deposit$ f sea wat] are !re=e likely to conta9 ?is sub/ance 7see ,/assfurt salts74 ,x is v sp>+ly soluble 9 wat]1 & is ?r[n d[n z a f9e :ite precipitate :5 any consid]able am\nts ( a calcium salt & a soluble sulphate 7or sulphuric acid7 are br\ght toge!r 9 solution4 ,its *ief use is 9 ! manufacture ( pla/] ( ,p>is & ( holl[ tiles = firepro( walls4 ,su* mat]ial is call$ gypsite4 ,x is also us$ z a f]tiliz]4 ,calcium sulphate1 l ! c>bonate1 occurs 9 _m =ms 9 nature4 ,gypsum is a "n giv5 to all common v>ieties4 ,granul> or massive specim5s are call$ alaba/]1 :ile all ^? :i* are well cry/alliz$ are call$ sel5ite4 ,sat9 sp> is /ill ano!r v>iety (t5 se5 9 m9]al collections4 ,pla/] ( ,p>is4 ,:5 gypsum is heat$ to ab\t #aae x loses a portion ( its wat] ( cry/allization 9 accordance ) ! equation #b7;,ca,s,o#db;,h#b,o7 #b;,ca,s,o#d;,h#b,o #b;,h#b,o4 ,! product is a f9e :ite p[d] call$ pla/] ( ,p>is4 ,on be+ moi/5$ x aga9 takes up ?is wat]1 & 9 s do+ fir/ =ms a pla/ic mass1 :i* soon becomes v firm & h>d & rega9s its cry/all9e /ructure4 ,^! prop]ties make x v valuable z a mat]ial = =m+ ca/s & /ucco "w1 = cem5t+ glass to metals1 & = o!r simil> purposes4 ,if ov]heat$ s t all wat] is driv5 (f1 ! process ( tak+ up wat] is s sl[ t ! mat]ial is wor?less4 ,su* mat]ial is said to be dead burn$4 ,pla/] ( ,p>is is v ext5sively us$ z ! f9i%+ coat = pla/]$ walls4 ,h>d wat]4 ,wat]s conta9+ comp\nds ( calcium & magnesium 9 solution are call$ h>d wat]s because !y feel h>% to ! t\*4 ,! h>dness ( wat] may be ( two k9ds1--7#a7 tempor>y h>dness & 7#b7 p]man5t h>dness4 #a4 ,tempor>y h>dness4 ,we h se5 t :5 wat] *>g$ ) c>bon dioxide comes 9 contact ) lime/one a c]ta9 am\nt ( ! latt] dissolves1 ow+ to ! =mation ( ! soluble acid c>bonate ( calcium4 ,! h>dness ( su* wat]s is said to be tempor>y1 s9ce x may be remov$ by boil+4 ,! heat *anges ! acid c>bonate into ! insoluble normal c>bonate :i* !n precipitates1 r5d]+ ! wat] s(t3 ,ca7,,hco#c7b ,ca,c,o#c ,h#b,o ,,co#b4 ,su* wat]s may also be s(t5$ by ! addition ( suffici5t lime or calcium hydroxide to conv]t ! acid c>bonate ( calcium into ! normal c>bonate4 ,! equation repres5t+ ! reaction is ,ca7,,hco#c7b ,ca7,,oh7#b #b;,ca,c,o#c #b;,h#b,o4 #b4 ,p]man5t h>dness4 ,! h>dness ( wat] may also be due to ! pres5ce ( calcium & magnesium sulphates or *lorides4 ,boil+ ! wat] does n affect ^! salts2 h5ce su* wat]s are said to h p]man5t h>dness4 ,!y may be s(t5$1 h[ev]1 by ! addition ( sodium c>bonate1 :i* precipitates ! calcium & magnesium z insoluble c>bonates3 ,ca,s,o#d ,na#b;,,co#c ,ca,c,o#c ,na#b,,s#d4 ,?is process is sometimes call$ break+ ! wat]4 ,comm]cial me?ods = s(t5+ wat]4 ,! av]age wat] ( a city supply conta9s n only ! acid c>bonates ( calcium & magnesium b also ! sulphates & *lorides ( ^! metals1 toge!r ) o!r salts 9 small] quantities4 ,su* wat]s are s(t5$ on a comm]cial scale by ! addition ( ! prop] quantities ( calcium hydroxide & sodium c>bonate4 ,! calcium hydroxide is add$ fir/ to precipitate all ! acid c>bonates4 ,aft] a %ort "t ! sodium c>bonate is add$ to precipitate ! o!r soluble salts ( calcium & magnesium1 toge!r ) any excess ( calcium hydroxide :i* may h be5 add$4 ,! quantity ( calcium hydroxide & sodium c>bonate requir$ is calculat$ f a *emical analysis ( ! wat]4 ,x w be notic$ t ! wat] s(t5$ 9 ?is way w conta9 sodium sulphate & *loride1 b ! pres5ce ( ^! salts is n objectionable4 ,calcium c>bide 7,ca,c#b74 ,?is sub/ance is made by heat+ well-dri$ coke & lime 9 an electrical furnace4 ,! equation is ,ca,o #c;,c ,ca,c#b ,,co4 ,! pure c>bide is a colorless1 transp>5t1 cry/all9e sub/ance4 ,9 contact ) wat] x is decompos$ ) ! evolution ( pure acetyl5e gas1 hav+ a pleasant e!real odor4 ,! comm]cial article is a dull gray por\s sub/ance :i* conta9s _m impurities4 ,! acetyl5e prep>$ f ?is sub/ance has a v *>act]i/ic odor due to impurities1 ! *ief ( ^! be+ phosph9e4 ,x is us$ 9 consid]able quantities z a s\rce ( acetyl5e gas = illum9at+ purposes4 ,te*nical prep>ation4 ,fig4 #ha repres5ts a rec5t type ( a c>bide furnace4 ,! base ( ! furnace is provid$ ) a l>ge block ( c>bon ,a1 :i* s]ves z "o ( ! electrodes4 ,! o!r electrodes ,b1 sev]al 9 numb]1 are arrang$ horizontally at "s di/ance above ?is4 ,a mixture ( coal & lime is f$ into ! furnace ?r\gh ! trap top ,c1 & 9 ! l[] "p ( ! furnace ?is mixture becomes int5sely heat$1 =m+ liquid c>bide4 ,?is is drawn (f ?r\gh ! taphole ,d4 ,! c>bon monoxide =m$ 9 ! reaction escapes ?r\gh ! pipes ,e & is l$ back into ! furnace4 ,! pipes ,f supply air1 s t ! monoxide burns z x rent]s ! furnace & assi/s 9 heat+ ! *>ge4 ,! c>bon dioxide s =m$1 toge!r ) ! nitrog5 ent]+ z air1 escape at ,g4 ,an alt]nat+ curr5t is us$4 ,illu/ration3 ,fig4 #ha ,calcium phosphate 7,ca#c7,,po#d7b74 ,?is important sub/ance occurs abundantly 9 nature z a con/itu5t ( apatite 7#c;,ca#c7,,po#d7b;,ca,f#b71 9 phosphate rock1 & z ! *ief m9]al con/itu5t ( bones4 ,bone a% is !re=e ne>ly pure calcium phosphate4 ,x is a :ite p[d]1 insoluble 9 wat]1 al?\gh x readily dissolves 9 acids1 be+ decompos$ by !m & conv]t$ into soluble acid phosphates1 z expla9$ 9 connection ) ! acids ( phosphorus4 ,,/rontium ,occurr5ce4 ,/rontium occurs sp>+ly 9 nature1 usually z /rontianite 7,sr,c,o#c7 & z cele/ite 7,sr,s,o#d74 ,bo? m9]als =m beautiful colorless cry/als1 ?\gh cele/ite is sometimes color$ a fa9t blue4 ,only a few ( ! comp\nds ( /rontium h any comm]cial applications4 ,/rontium hydroxide 7,sr7,,oh7#bh;,h#b,o74 ,! me?od ( prep>ation ( /rontium hydroxide is analog\s to t ( calcium hydroxide4 ,! sub/ance has ! prop]ty ( =m+ an insoluble comp\nd ) sug>1 :i* c easily be sep>at$ aga9 into its con/itu5ts4 ,x is !re=e sometimes us$ 9 ! sug> ref9]ies to extract sug> f impure "m liquors f :i* ! sug> w n cry/allize4 ,/rontium nitrate 7,sr7,,no#c7bd;,h#b,o74 ,?is salt is prep>$ by treat+ ! native c>bonate ) nitric acid4 ,:5 ignit$ ) combu/ible mat]ials x imp>ts a brilliant crimson color to ! flame1 & because ( ?is prop]ty x is us$ 9 ! manufacture ( r$ lights4 ,,b>ium ,b>ium is some:at m abundant ?an /rontium1 occurr+ 9 nature l>gely z b>ytes1 or heavy sp> 7,ba,s,o#d71 & )]ite 7,ba,c,o#c74 ,l /rontium1 x closely resembles calcium bo? 9 ! prop]ties ( ! metal & 9 ! comp\nds :i* x =ms4 ,oxides ( b>ium4 ,b>ium oxide 7,ba,o7 c be obta9$ by /rongly heat+ ! nitrate3 ,ba7,,no#c7b ,ba,o #b,,no#b ,o4 ,heat$ to a l[ r$ heat 9 ! air1 ! oxide comb9es ) oxyg51 =m+ ! p]oxide 7,ba,o#b74 ,if ! temp]ature is rais$ /ill high]1 or ! pressure is r$uc$1 oxyg5 is giv5 (f & ! oxide is once m =m$4 ,! reaction ,ba,o#b -- ,ba,o ,o is rev]sible & has be5 us$ z a means ( sep>at+ oxyg5 f ! air4 ,treat$ ) acids1 b>ium p]oxide yields hydrog5 p]oxide3 ,ba,o#b #b;,h,cl ,ba,cl#b ,h#b,o#b4 ,b>ium *loride 7,ba,cl#bb;,h#b,o74 ,b>ium *loride is a :ite well-cry/alliz$ sub/ance :i* is easily prep>$ f ! native c>bonate4 ,x is l>gely us$ 9 ! laboratory z a reag5t to detect ! pres5ce ( sulphuric acid or soluble sulphates4 ,b>ium sulphate 7b>ytes7 7,ba,s,o#d74 ,b>ium sulphate occurs 9 nature 9 ! =m ( heavy :ite cry/als4 ,x is precipitat$ z a cry/all9e p[d] :5 a b>ium salt is add$ to a solution ( a sulphate or sulphuric acid3 ,ba,cl#b ,h#b,,s#d ,ba,s,o#d #b;,h,cl4 ,?is precipitate is us$1 z are also ! f9ely gr\nd native sulphate & c>bonate1 z a pigm5t 9 pa9ts4 ,on acc\nt ( its l[ co/ x is sometimes us$ z an adult]ant ( :ite lead1 :i* is also a heavy :ite sub/ance4 ,b>ium comp\nds color ! flame gre51 & ! nitrate 7,ba7,,no#c7b7 is us$ 9 ! manufacture ( gre5 lights4 ,soluble b>ium comp\nds are poison\s4 ,,radium ,hi/orical4 ,9 #ahif ! ,fr5* sci5ti/ ,becqu]el obs]v$ t ! m9]al pit*bl5de possesses c]ta9 rem>kable prop]ties4 ,x affects photographic plates ev5 9 complete d>kness1 & dis*>ges a gold-leaf electroscope :5 br\ght close to x4 ,9 #ahih ,madam ,curie made a c>eful /udy ( pit*bl5de to see if ^! prop]ties belong to x or to "s unkn[n sub/ance conta9$ 9 x4 ,%e succe$$ 9 extract+ f x a v small quantity ( a sub/ance conta9+ a new elem5t :i* %e nam$ radium4 ,9 #aiaj ,madam ,curie succe$$ 9 obta9+ radium itself by ! electrolysis ( radium *loride4 ,x is a silv]-:ite metal melt+ at ab\t #gjj4 ,x black5s 9 ! air1 =m+ a nitride1 & decomposes wat]4 ,its atomic weight is ab\t #bbf4e4 ,prop]ties4 ,comp\nds ( radium affect a photographic plate or electroscope ev5 ?r\gh lay]s ( pap] or %eets ( metal4 ,!y also br+ ab\t *emical *anges 9 sub/ances plac$ ne> !m4 ,inve/igation ( ^! /range prop]ties has sugge/$ t ! radium atoms are un/able & und]go a decomposition4 ,z a result ( ?is decomposition v m9ute bodies1 to :i* ! "n corpuscles has be5 giv51 are project$ f ! radium atom ) exce$+ly great velocity4 ,x is to ^! corpuscles t ! /range prop]ties ( radium are due4 ,x seems probable t ! gas helium is 9 "s way =m$ dur+ ! decomposition ( radium4 ,two or ?ree o!r elem5ts1 p>ticul>ly uranium & ?orium1 h be5 f\nd to possess _m ( ! prop]ties ( radium 9 small] degree4 ,radium & ! atomic !ory4 ,if ^! views 9 reg>d to radium %\ld prove to be well f\nd$1 x w be necess>y to modify 9 "s respects ! conception ( ! atom z develop$ 9 a =m] *apt]4 ,! atom w\ld h to be reg>d$ z a comp\nd unit made up ( sev]al p>ts4 ,9 a few cases1 z 9 radium & uranium1 x w\ld appe> t ?is unit is un/able & und]goes trans=mation into m /able comb9ations4 ,?is modification w\ld n1 9 any ess5tial way1 be at v>iance ) ! atomic !ory z prop\nd$ by ,dalton4 ,,ex]cises #a4 ,:at prop]ties h ! alkal9e-e>? metals 9 common ) ! alkali metals8 ,9 :at respects d !y diff]8 #b4 ,write ! equation = ! reaction betwe5 calcium c>bide & wat]4 #c4 ,= :at is calcium *lorate us$8 #d4 ,c\ld lime/one be completely decompos$ if heat$ 9 a clos$ vessel8 #e4 ,caves (t5 occur 9 lime/one4 ,acc\nt = _! =mation4 #f4 ,:at is ! significance ( ! t]m fluorsp>8 7,consult diction>y47 #g4 ,c\ld calcium *loride be us$ 9 place ( b>ium *loride 9 te/+ = sulphates8 #h4 ,:at weight ( wat] is necess>y to slake ! lime obta9$ f #a ton ( pure calcium c>bonate8 #i4 ,:at weight ( gypsum is necess>y 9 ! prep>ation ( #a ton ( pla/] ( ,p>is8 #aj4 ,write equations to repres5t ! reactions involv$ 9 ! prep>ation ( /rontium hydroxide & /rontium nitrate f /rontianite4 #aa4 ,write equations to repres5t ! reactions involv$ 9 ! prep>ation ( b>ium *loride f heavy sp>4 #ab4 ,c\ld b>ium hydroxide be us$ 9 place ( calcium hydroxide 9 te/+ = c>bon dioxide8 ,,*apt] ,,xxv ,,! ,,magnesium ,,family ,,symbol ,,atomic ,,d5sity ,,melt+ ,,boil+ ,,oxide ,,weight ,,po9t ,,po9t ---------------------------------------- ----------------------------------- ,magnesium ,mg #bd4cf #a4ge #gej #ibj ,mg,o ,z9c ,zn #fe4d #g4jj #dbj #iej ,zn,o ,cadmium ,cd #aab4d #h4fg #cbj #ggh ,cd,o ,! family4 ,9 ! magnesium family are includ$ ! f\r elem5ts3 magnesium1 z9c1 cadmium1 & m]cury4 ,betwe5 ! fir/ ?ree ( ^! metals !re is a close family resemblance1 su* z has be5 trac$ betwe5 ! memb]s ( ! two prec$+ families4 ,m]cury 9 "s respects is m simil> to copp] & w be /udi$ 9 connection ) t metal4 #a4 ,prop]ties4 ,:5 heat$ to a high temp]ature 9 ! air ea* ( ^! metals comb9es ) oxyg5 to =m an oxide ( ! g5]al =mula ,,mo1 9 :i* ,m repres5ts ! metal4 ,magnesium decomposes boil+ wat] sl[ly1 :ile z9c & cadmium h b little action on x4 #b4 ,comp\nds4 ,! memb]s ( ?is gr\p are dival5t 9 ne>ly all _! comp\nds1 s t ! =mulas ( _! salts resemble ^? ( ! alkal9e-e>? metals4 ,l ! alkal9e-e>? metals1 _! c>bonates & phosphates are insoluble 9 wat]4 ,_! sulphates1 h[ev]1 are readily soluble4 ,unlike bo? ! alkali & alkal9e-e>? metals1 _! hydroxides are ne>ly insoluble 9 wat]4 ,mo/ ( _! comp\nds dissociate 9 su* a way z to give a simple1 colorless1 metallic ion4 ,,magnesium ,occurr5ce4 ,magnesium is a v abundant elem5t 9 nature1 rank+ a little bel[ calcium 9 ?is respect4 ,l calcium1 x is a con/itu5t ( _m rocks & also occurs 9 ! =m ( soluble salts4 ,prep>ation4 ,! metal magnesium1 l mo/ metals ^: oxides are difficult to r$uce ) c>bon1 0 =m]ly prep>$ by heat+ ! anhydr\s *loride ) sodium3 ,mg,cl#b #b,na #b,na,cl ,mg4 ,x is n[ made by electrolysis1 b in/ead ( us+ z ! electrolyte ! melt$ anhydr\s *loride1 :i* is difficult to obta91 ! natural m9]al c>nallite is us$4 ,?is is melt$ 9 an iron pot :i* also s]ves z ! ca?ode 9 ! electrolysis4 ,a rod ( c>bon dipp+ into ! melt$ salt s]ves z ! anode4 ,! app>atus is v simil> to ! "o employ$ 9 ! prep>ation ( sodium4 ,prop]ties4 ,magnesium is a r t\gh silv]y-:ite metal ( small d5sity4 ,air does n act rapidly ^u x1 b a ?9 film ( oxide =ms ^u its surface1 dimm+ its bright lu/]4 ,! common acids dissolve x ) ! =mation ( ! correspond+ salts4 ,x c be ignit$ readily & 9 burn+ lib]ates mu* heat & gives a brilliant :ite light4 ,?is light is v ri* 9 ! rays :i* affect photographic plates1 & ! metal 9 ! =m ( f9e p[d] is ext5sively us$ 9 ! production ( fla% lights & = :ite lights 9 pyrote*nic displays4 ,magnesium oxide 7magnesia7 7,mg,o74 ,magnesium oxide1 sometimes call$ magnesia or magnesia u/a1 resembles lime 9 _m respects4 ,x is mu* m easily =m$ ?an lime & c be made 9 ! same way1--by ignit+ ! c>bonate4 ,x is a :ite p[d]1 v s(t & light1 & is un*ang$ by heat ev5 at v high temp]atures4 ,= ?is reason x is us$ 9 ! manufacture ( crucibles1 = l9+ furnaces1 & = o!r purposes :]e a refractory sub/ance is ne$$4 ,x comb9es ) wat] to =m magnesium hydroxide1 b mu* m sl[ly & ) ! production ( mu* less heat ?an 9 ! case ( calcium oxide4 ,magnesium hydroxide 7,mg7,,oh7#b74 ,! hydroxide =m$ 9 ?is way is v slightly soluble 9 wat]1 b en\gh dissolves to give ! wat] an alkal9e reaction4 ,magnesium hydroxide is !re=e a fairly /rong base4 ,x is an amorph\s :ite sub/ance4 ,nei!r magnesia nor magnesium salts h a v m>k$ effect ^u ! sy/em2 & = ?is reason magnesia is a v suitable antidote = poison+ by /rong acids1 s9ce any excess introduc$ into ! sy/em w h no injuri\s effect4 ,magnesium cem5t4 ,a pa/e ( magnesium hydroxide & wat] sl[ly absorbs c>bon dioxide f ! air & becomes v h>d4 ,! h>dness ( ! product is increas$ by ! pres5ce ( a consid]able am\nt ( magnesium *loride 9 ! pa/e4 ,! hydroxide1 ) or )\t ! *loride1 is us$ 9 ! prep>ation ( cem5ts = "s purposes4 ,magnesium c>bonate 7,mg,c,o#c74 ,magnesium c>bonate is a v abundant m9]al4 ,x occurs 9 a numb] ( localities z magnesite1 :i* is usually amorph\s1 b sometimes =ms pure cry/als resembl+ calcite4 ,m commonly x is f\nd associat$ ) calcium c>bonate4 ,! m9]al dolomite has ! composition ,ca,c,o#c,mg,c,o#c4 ,lime/one conta9+ small] am\nts ( magnesium c>bonate is kn[n z dolomitic lime/one4 ,dolomite is "o ( ! mo/ common rocks1 =m+ :ole m\nta9 masses4 ,x is h>d] & less readily attack$ by acids ?an lime/one4 ,x is valuable z a build+ /one & z balla/ = roadb$s & f\ndations4 ,l calcium c>bonate1 magnesium c>bonate is insoluble 9 wat]1 ?\gh easily dissolv$ by acids4 ,basic c>bonate ( magnesium4 ,we %\ld expect to f9d magnesium c>bonate precipitat$ :5 a soluble magnesium salt & a soluble c>bonate are br\ght toge!r3 ,na#b;,,co#c ,mg,cl#b ,mg,c,o#c #b,na,cl4 ,in/ead ( ?is1 "s c>bon dioxide escapes & ! product is f\nd to be a basic c>bonate4 ,! mo/ common basic c>bonate ( magnesium has ! =mula #d,mg,c,o#c,mg7,,oh7#b1 & is sometimes call$ magnesia alba4 ,?is comp\nd is =m$ by ! p>tial hydrolysis ( ! normal c>bonate at fir/ precipitat$3 #e,mg,c,o#c #b;,h#b,o #d,mg,c,o#c,mg7,,oh7#b ,h#b;,,co#c4 ,magnesium *loride 7,mg,cl#bf;,h#b,o74 ,magnesium *loride is f\nd 9 _m natural wat]s & 9 _m salt deposits 7see ,/assfurt salts74 ,x is obta9$ z a by-product 9 ! manufacture ( potassium *loride f c>nallite4 ,z !re is no v important use = x1 l>ge quantities annually g to wa/e4 ,:5 heat$ to drive (f ! wat] ( cry/allization ! *loride is decompos$ z %[n 9 ! equation ,mg,cl#bf;,h#b,o ,mg,o #b;,h,cl #e;,h#b,o4 ,ow+ to ! abundance ( magnesium *loride1 ?is reaction is be+ us$ to "s ext5t 9 ! prep>ation ( bo? magnesium oxide & hydro*loric acid4 ,boil] scale4 ,:5 wat] :i* conta9s c]ta9 salts 9 solution is evaporat$ 9 /eam boil]s1 a h>d insoluble mat]ial call$ scale deposits 9 ! boil]4 ,! =mation ( ?is scale may be due to sev]al di/9ct causes4 #a4 ,to ! deposit ( calcium sulphate4 ,?is salt1 :ile sp>+ly soluble 9 cold wat]1 is almo/ completely insoluble 9 sup]heat$ wat]4 ,consequ5tly x is precipitat$ :5 wat] conta9+ x is heat$ 9 a boil]4 #b4 ,to decomposition ( acid c>bonates4 ,z we h se51 calcium & magnesium acid c>bonates are decompos$ on heat+1 =m+ insoluble normal c>bonates3 ,ca7,,hco#c7b ,ca,c,o#c ,h#b,o ,,co#b4 #c4 ,to hydrolysis ( magnesium salts4 ,magnesium *loride1 & to "s ext5t magnesium sulphate1 und]go hydrolysis :5 sup]heat$ 9 solution1 & ! magnesium hydroxide1 be+ sp>+ly soluble1 precipitates3 ,mg,cl#b #b;,h#b,o -- ,mg7,,oh7#b #b;,h,cl4 ,?is scale adh]es tightly to ! boil] 9 compact lay]s &1 be+ a non-conductor ( heat1 causes mu* wa/e ( fuel4 ,x is v difficult to remove1 ow+ to its h>dness & resi/ance to reag5ts4 ,?ick scale sometimes cracks1 & ! wat] com+ 9 contact ) ! ov]heat$ iron occasions an explosion4 ,moreov]1 ! acids set free 9 ! hydrolysis ( ! magnesium salts attack ! iron tubes & rapidly corrode !m4 ,^! causes comb9e to make ! =mation ( scale a matt] :i* occasions mu* tr\ble 9 cases :]e h>d wat] is us$ 9 /eam boil]s4 ,wat] conta9+ su* salts %\ld be s(t5$1 !re=e1 be=e be+ us$ 9 boil]s4 ,magnesium sulphate 7,epsom salt7 7,mg,s,o#dg;,h#b,o74 ,l ! *loride1 magnesium sulphate is f\nd r commonly 9 spr+s & 9 salt deposits4 ,a v l>ge deposit ( ! almo/ pure salt has be5 f\nd 9 ,wyom+4 ,its "n 0 giv5 to x because ( its abundant occurr5ce 9 ! wat]s ( ! ,epsom spr+s 9 ,engl&4 ,magnesium sulphate has _m uses 9 ! indu/ries4 ,x is us$ to a small ext5t 9 ! prep>ation ( sodium & potassium sulphates1 z a coat+ = cotton clo?1 9 ! dye indu/ry1 9 tann+1 & 9 ! manufacture ( pa9ts & laundry soaps4 ,to "s ext5t x is us$ 9 m$ic9e4 ,magnesium silicates4 ,_m silicates conta9+ magnesium are kn[n & "s ( !m are important sub/ances4 ,s]p5t9e1 asbe/os1 talc1 & me]s*aum are examples ( su* sub/ances4 ,,z9c ,occurr5ce4 ,z9c nev] occurs free 9 nature4 ,its comp\nds h be5 f\nd 9 _m diff]5t c\ntries1 b x is n a con/itu5t ( common rocks & m9]als1 & its occurr5ce is r local & conf9$ to def9ite deposits or pockets4 ,x occurs *iefly 9 ! foll[+ ores3 ,sphal]ite 7z9c bl5de7 ,zn,s4 ,z9cite ,zn,o4 ,smi?sonite ,zn,c,o#c4 ,willemite ,zn#b,si,o#d4 ,frankl9ite ,zn,o,fe#b,o#c4 ,"o f\r? ( ! _w's output ( z9c comes f ! ,unit$ ,/ates1 ,miss\ri be+ ! l>ge/ produc]4 ,metallurgy4 ,! ores employ$ 9 ! prep>ation ( z9c are *iefly ! sulphide1 oxide1 & c>bonate4 ,!y are fir/ roa/$ 9 ! air1 by :i* process !y are *ang$ into oxide3 ,zn,c,o#c ,zn,o ,,co#b1 ,zn,s #c,o ,zn,o ,,s#b4 ,! oxide is !n mix$ ) coal du/1 & ! mixture is heat$ 9 e>!nw>e muffles or retorts1 natural gas be+ us$ z fuel 9 _m cases4 ,! oxide is r$uc$ by ?is means to ! metallic /ate1 & ! z9c1 be+ volatile at ! high temp]ature rea*$1 di/ills & is collect$ 9 suitable receiv]s4 ,at fir/ ! z9c collects 9 ! =m ( f9e p[d]1 call$ z9c du/ or fl[]s ( z9c1 recall+ ! =mation "u simil> conditions ( fl[]s ( sulphur4 ,lat]1 :5 ! :ole app>atus has become w>m1 ! z9c cond5ses to a liquid 9 ! receiv]1 f :i* x is drawn (f into molds4 ,comm]cial z9c (t5 conta9s a numb] ( impurities1 especially c>bon1 ars5ic1 & iron4 ,physical prop]ties4 ,pure z9c is a r heavy blui%-:ite metal ) a high lu/]4 ,x melts at ab\t #dbj1 & if heat$ mu* above ?is temp]ature 9 ! air takes fire & burns ) a v bright blui% flame4 ,x boils at ab\t #iej & c !re=e be purifi$ by di/illation4 ,_m ( ! physical prop]ties ( z9c are mu* influ5c$ by ! temp]ature & previ\s treatm5t ( ! metal4 ,:5 ca/ into +ots f ! liquid /ate x becomes at ord9>y temp]atures q h>d1 brittle1 & highly cry/all9e4 ,at #aej x is malleable & c be roll$ into ?9 %eets2 at high] temp]atures x aga9 becomes v brittle4 ,:5 once roll$ into %eets x reta9s its s(tness & malleability at ord9>y temp]atures4 ,:5 melt$ & p\r$ into wat] x =ms ?9 brittle flakes1 & 9 ?is condition is call$ granulat$ or mossy z9c4 ,*emical prop]ties4 ,z9c is t>ni%$ sup]ficially by moi/ air1 b beyond ?is is n affect$ by x4 ,x does n decompose ev5 boil+ wat]4 ,:5 ! metal is q pure1 sulphuric & hydro*loric acids h sc>cely any action ^u x2 :51 h[ev]1 x conta9s small am\nts ( o!r metals su* z magnesium or ars5ic1 or :5 x is m]ely 9 contact ) metallic plat9um1 brisk action takes place & hydrog5 is evolv$4 ,= ?is reason1 :5 pure z9c is us$ 9 ! prep>ation ( hydrog5 a few drops ( plat9um *loride are (t5 add$ to ! solution to assi/ ! *emical action4 ,nitric acid dissolves ! metal readily1 ) ! =mation ( z9c nitrate & v>i\s r$uction products ( nitric acid4 ,! /rong alkalis act ^u z9c & lib]ate hydrog53 ,zn #b,,koh ,zn7,,ok7#b #b;,h4 ,! product ( ?is reaction1 potassium z9cate1 is a salt ( z9c hydroxide1 :i* is ?us se5 to h acid prop]ties1 ?\gh x usually acts z a base4 ,uses ( z9c4 ,! metal has _m famili> uses4 ,roll$ into %eets1 x is us$ z a l9+ = vessels :i* are to conta9 wat]4 ,z a ?9 film ^u ! surface ( iron 7galvaniz$ iron7 x protects ! iron f ru/4 ,iron is usually galvaniz$ by dipp+ x into a ba? ( melt$ z9c1 b electrical me?ods are also employ$4 ,z9c plates are us$ 9 _m =ms ( electrical batt]ies4 ,9 ! laboratory z9c is us$ 9 ! prep>ation ( hydrog51 & 9 ! =m ( z9c du/ z a r$uc+ ag5t4 ,"o ( ! l>ge/ uses ( z9c is 9 ! manufacture ( alloys4 ,brass1 an alloy ( z9c & copp]1 is ! mo/ important ( ^!2 ,g]man silv]1 consi/+ ( copp]1 z9c1 & nickel1 has _m uses2 v>i\s bronzes1 co9 metals1 & be>+ metals also conta9 z9c4 ,its ability to alloy ) silv] f9ds application 9 ! sep>ation ( silv] f lead 7see silv]74 ,comp\nds ( z9c4 ,9 g5]al1 ! comp\nds ( z9c are simil> 9 =mula & appe>ance to ^? ( magnesium1 b 9 o!r prop]ties !y (t5 diff] m>k$ly4 ,a numb] ( !m h value 9 comm]cial ways4 ,z9c oxide 7z9c :ite7 7,zn,o74 ,z9c oxide occurs 9 impure =m 9 nature1 be+ color$ r$ by manganese & iron comp\nds4 ,x c be prep>$ j l magnesium oxide1 b is m (t5 made by burn+ ! metal4 ,z9c oxide is a pure :ite p[d] :i* becomes yell[ on heat+ & rega9s its :ite color :5 cold4 ,x is mu* us$ z a :ite pigm5t 9 pa9ts1 "u ! "n ( z9c :ite1 & has ! advantage ov] :ite lead 9 t x is n *ang$ 9 color by sulphur comp\nds1 :ile lead turns black4 ,x is also us$ 9 ! manufacture ( rubb] goods4 ,comm]cial prep>ation ( z9c oxide4 ,comm]cially x is (t5 made f frankl9ite 9 ! foll[+ way4 ,! frankl9ite is mix$ ) coal & heat$ to a high temp]ature 9 a furnace1 by :i* process ! z9c is set free & conv]t$ into vapor4 ,z ! vapor leaves ! furnace ?r\gh a conduit x meets a curr5t ( air & takes fire 9 x1 =m+ z9c oxide4 ,! oxide passes on & is filt]$ f ! air ?r\gh canvas bags1 :i* all[ ! air to pass b reta9 ! oxide4 ,x is ?us made by burn+ ! metal1 ?\gh ! metal is n actually isolat$ 9 ! process4 ,soluble salts4 ,! soluble salts ( z9c c be made by dissolv+ ! metal or ! oxide 9 ! appropriate acid4 ,!y are all some:at poison\s4 ,! sulphate & *loride are ! mo/ famili>4 ,z9c sulphate 7:ite vitriol7 7,zn,s,o#dg;,h#b,o74 ,?is salt is readily cry/alliz$ f /rong solutions 9 transp>5t colorless cry/als4 ,x is prep>$ comm]cially by c>eful roa/+ ( ! sulphide3 ,zn,s #d,o ,zn,s,o#d4 ,z9c *loride 7,zn,cl#b;,h#b,o74 ,:5 a solution ( z9c *loride is sl[ly evaporat$ a salt ( ! composition ,zn,cl#b;,h#b,o cry/allizes out4 ,if ! wat] is completely expell$ by heat & ! residue di/ill$1 ! anhydr\s *loride is obta9$ & may be ca/ into /icks or brok5 into lumps4 ,9 ?is di/illation1 j z 9 heat+ magnesium *loride1 "s ( ! *loride is decompos$3 ,zn,cl#b;,h#b,o ,zn,o #b;,h,cl4 ,! anhydr\s *loride has a great aff9ity = wat]1 & is us$ z a dehydrat+ ag5t4 ,x is also a g]micide1 & wood :i* is to be expos$ to conditions :i* favor decay1 z1 = example1 railroad ties1 is (t5 soak$ 9 solutions ( ?is salt4 ,insoluble comp\nds4 ,! insoluble comp\nds ( z9c c be prep>$ by precipitation4 ,! mo/ important are ! sulphide1 c>bonate1 & hydroxide4 ,z9c sulphide 7,zn,s74 ,?is sub/ance occurs z ! m9]al sphal]ite1 & is "o ( ! mo/ valu$ ores ( z9c4 ,v l>ge deposits occur 9 s\?we/]n ,miss\ri4 ,! natural m9]al is f\nd 9 l>ge cry/als or masses1 resembl+ res9 9 color & lu/]4 ,:5 prep>$ by precipitation ! sulphide is :ite4 ,,cadmium ,! elem5t4 ,?is elem5t occurs 9 small quantities 9 "s z9c ores4 ,9 ! c\rse ( ! metallurgy ( z9c ! cadmium comp\nds und]go *emical *anges q simil> to ^? ( ! z9c comp\nds1 & ! cadmium di/ills along ) ! z9c4 ,be+ m volatile1 x comes ov] ) ! fir/ ( ! z9c & is prep>$ f ! fir/ portions ( ! di/illate by special me?ods ( purification4 ,! elem5t v closely resembles z9c 9 mo/ respects4 ,"s ( its alloys are *>act]iz$ by hav+ l[ melt+ po9ts4 ,comp\nds ( cadmium4 ,among ! comp\nds ( cadmium may be m5tion$ ! *loride 7,cd,cl#bb;,h#b,o71 ! sulphate 7#c;,cd,s,o#dh;,h#b,o71 & ! nitrate 7,cd7,,no#c7bd;,h#b,o74 ,^! are :ite solids soluble 9 wat]4 ,! sulphide 7,cd,s7 is a bright yell[ sub/ance :i* is insoluble 9 wat] & 9 dilute acids4 ,x is valuable z a pigm5t 9 f9e pa9ts4 ,,ex]cises #a4 ,:at prop]ties h ! metals ( ! magnesium family 9 common ) ! alkali metals2 ) ! alkal9e-e>? metals8 #b4 ,comp>e ! action ( ! metals ( ! magnesium gr\p on wat] ) t ( ! o!r metals /udi$4 #c4 ,:at metals already /udi$ are prep>$ by electrolysis8 #d4 ,write ! equations repres5t+ ! reactions betwe5 magnesium & hydro*loric acid2 betwe5 magnesium & dilute sulphuric acid4 #e4 ,:at prop]ty ( magnesium 0 tak5 advantage ( 9 ! isolation ( argon8 #f4 ,) phosphoric acid magnesium =ms salts simil> to ^? ( calcium4 ,write ! names & =mulas ( ! correspond+ magnesium salts4 #g4 ,h[ c\ld y di/+ui% betwe5 magnesium *loride & magnesium sulphate8 betwe5 ,glaub]'s salts & ,epsom salts8 #h4 ,:at weight ( c>nallite is necess>y 9 ! prep>ation ( #ejj g4 ( magnesium8 #i4 ,acc\nt = ! fact t pa9ts made ( z9c oxide are n color$ by hydrosulphuric acid4 #aj4 ,:at hydroxide /udi$1 o!r ?an z9c hydroxide1 has bo? acid & basic prop]ties8 #aa4 ,write equations %[+ h[ ! foll[+ comp\nds ( z9c may be obta9$ f metallic z9c3 ! oxide1 *loride1 nitrate1 c>bonate1 sulphate1 sulphide1 hydroxide4 ,,*apt] ,,xxvi ,,! ,,alum9ium ,,family ,! family4 ,! elem5t alum9ium is ! mo/ abundant memb] ( ! gr\p ( elem5ts kn[n z ! alum9ium family2 inde$1 ! o!r memb]s ( ! family--gallium1 indium1 & ?allium--are ( su* r>e occurr5ce t !y ne$ n be sep>ately describ$4 ,! elem5ts ( ! family are ord9>ily trival5t1 s t ! =mulas = _! comp\nds diff] f ^? ( ! elem5ts s f> /udi$4 ,_! hydroxides are practically insoluble 9 wat] & are v weak bases2 inde$1 ! bases are s weak t _! salts are (t5 hydrolyz$ into free base & free acid 9 solution4 ,! salts =m$ f ^! bases usually conta9 wat] ( cry/allization1 :i* _c be driv5 (f )\t decompos+ !m m or less4 ,! trival5t metals1 :i* 9 addition to alum9ium include also iron & *romium1 are sometimes call$ ! e>? metals4 ,! "n ref]s to ! e>?y appe>ance ( ! oxides ( ^! metals1 & to ! fact t _m e>?s1 soils1 & rocks are compos$ 9 "p ( ^! sub/ances4 ,,alum9ium ,occurr5ce4 ,alum9ium nev] occurs 9 ! free /ate 9 nature1 ow+ to its great aff9ity = oxyg54 ,9 comb9$ =m1 z oxides1 silicates1 & a few o!r salts1 x is bo? abundant & widely di/ribut$1 be+ an ess5tial con/itu5t ( all soils & ( mo/ rocks except+ lime/one & s&/one4 ,cryolite 7,na#c;,al,f#f71 f\nd 9 ,gre5l&1 & bauxite1 :i* is an alum9ium hydroxide usually mix$ ) "s iron hydroxide1 are important m9]als4 ,x is e/imat$ t alum9ium composes ab\t #h ( ! e>?'s cru/4 ,9 ! indu/ries ! metal is call$ alum9um1 b its *emical "n is alum9ium4 ,illu/ration3 ,fig4 #hb ,prep>ation4 ,alum9ium 0 fir/ prep>$ by ,whl]1 9 #ahbg1 by heat+ anhydr\s alum9ium *loride ) potassium3 ,al,cl#c #c,k #c,k,cl ,al4 ,?is me?od 0 tri$ aft] x 0 f\nd impossible to r$uce ! oxide ( alum9ium ) c>bon4 ,! metal possess$ su* int]e/+ prop]ties & promis$ to be s useful t _m ef=ts 7 made to devise a *eap way ( prep>+ x4 ,! me?od :i* has prov$ mo/ successful consi/s 9 ! electrolysis ( ! oxide dissolv$ 9 melt$ cryolite4 ,metallurgy4 ,an iron box ,a 7,fig4 #hb7 ab\t eight feet long & six feet wide is connect$ ) a p[]ful g5]ator 9 su* a way z to s]ve z ! ca?ode ^u :i* ! alum9ium is deposit$4 ,?ree or f\r r[s ( c>bon rods ,b dip into ! box & s]ve z ! anodes4 ,! box is p>tially fill$ ) cryolite & ! curr5t is turn$ on1 g5]at+ en\gh heat to melt ! cryolite4 ,alum9ium oxide is !n add$1 & "u ! influ5ce ( ! electric curr5t x decomposes into alum9ium & oxyg54 ,! temp]ature is ma9ta9$ above ! melt+ po9t ( alum9ium1 & ! liquid metal1 be+ heavi] ?an cryolite1 s9ks to ! bottom ( ! vessel1 f :i* x is tapp$ (f f "t to "t ?r\gh ! tap hole ,c4 ,! oxyg5 9 "p escapes z gas1 & 9 "p comb9es ) ! c>bon ( ! anode1 ! combu/ion be+ v brilliant4 ,! process is c>ri$ on at ,niag>a ,falls4 ,! l>ge/ exp5se 9 ! process1 ap>t f ! co/ ( electrical en]gy1 is ! prep>ation ( alum9ium oxide free f o!r oxides1 = mo/ ( ! oxide f\nd 9 nature is too impure to s]ve )\t ref9+4 ,bauxite is ! pr9cipal ore us$ z a s\rce ( ! alum9ium because x is conv]t$ into pure oxide )\t great difficulty4 ,s9ce common clay is a silicate ( alum9ium & is ev]y:]e abundant1 x might be expect$ t ?is w\ld be utiliz$ 9 ! prep>ation ( alum9ium4 ,x is1 h[ev]1 v difficult to extract ! alum9ium f a silicate1 & no practical me?od has be5 f\nd :i* w accompli% ?is4 ,physical prop]ties4 ,alum9ium is a t9-:ite metal :i* melts at #fdj & is v light1 hav+ a d5sity ( #b4fh4 ,x is /iff & /rong1 & ) frequ5t anneal+ c be roll$ into ?9 foil4 ,x is a good conductor ( heat & electricity1 ?\gh n s good z copp] = a giv5 cross section ( wire4 ,*emical prop]ties4 ,alum9ium is n p]ceptibly act$ on by boil+ wat]1 & moi/ air m]ely dims its lu/]4 ,fur!r action is prev5t$ 9 ea* case by ! =mation ( an extremely ?9 film ( oxide ^u ! surface ( ! metal4 ,x comb9es directly ) *lor9e1 & :5 heat$ 9 oxyg5 burns ) great en]gy & ! lib]ation ( mu* heat4 ,x is !re=e a good r$uc+ ag5t4 ,hydro*loric acid acts ^u x1 =m+ alum9ium *loride3 nitric acid & dilute sulphuric acid h almo/ no action on x1 b hot1 conc5trat$ sulphuric acid acts ^u x 9 ! same way z ^u copp]3 #b;,al #f;,h#b,,s#d ,al#b7,,s#d7c #f;,h#b,o #c,,s#b4 ,alkalis readily attack ! metal1 lib]at+ hydrog51 z 9 ! case ( z9c3 ,al #c,,koh ,al7,,ok7#c #c;,h4 ,salt solutions1 su* z sea wat]1 corrode ! metal rapidly4 ,x alloys readily ) o!r metals4 ,uses ( alum9ium4 ,^! prop]ties sugge/ _m uses = ! metal4 ,its lightness1 /r5g?1 & p]man5ce make x well adapt$ = _m con/ruction purposes4 ,^! same prop]ties h l$ to its ext5sive use 9 ! manufacture ( cook+ ut5sils4 ,! fact t x is easily corrod$ by salt solutions is1 h[ev]1 a disadvantage4 ,ow+ to its small resi/ance to electrical curr5ts1 x is replac+ copp] to "s ext5t 9 electrical con/ruction1 especially = trolley & p[] wires4 ,"s ( its alloys h v valuable prop]ties1 & a consid]able "p ( ! alum9ium manufactur$ is us$ = ?is purpose4 ,alum9ium bronze1 consi/+ ( ab\t #ij copp] & #aj alum9ium1 has a pure gold5 color1 is /rong & malleable1 is easily ca/1 & is p]man5t 9 ! air4 ,consid]able am\nts ( alum9ium /eel are also made4 ,golds*midt r$uction process4 ,alum9ium is frequ5tly employ$ z a p[]ful r$uc+ ag5t1 _m metallic oxides :i* resi/ r$uction by c>bon be+ readily r$uc$ by x4 ,! alum9ium 9 ! =m ( a f9e p[d] is mix$ ) ! metallic oxide1 toge!r ) "s sub/ance su* z fluorsp> to act z a flux4 ,! mixture is ignit$1 & ! alum9ium unites ) ! oxyg5 ( ! metallic oxide1 lib]at+ ! metal4 ,?is collects 9 a fus$ condition "u ! flux4 ,an enorm\s quantity ( heat is lib]at$ 9 ?is reaction1 & a temp]ature z high z #cejj c be rea*$4 ,! heat ( ! reaction is turn$ to practical acc\nt 9 weld+ c> rails1 /eel ca/+s1 & 9 simil> op]ations :]e an int5se local heat is requir$4 ,a mixture ( alum9ium ) v>i\s metallic oxides1 ready prep>$ = su* purposes1 is sold "u ! "n ( !rmite4 ,illu/ration3 ,fig4 #hc ,prep>ation ( *romium by ! ,golds*midt me?od4 ,a mixture ( *romium oxide & alum9ium p[d] is plac$ 9 a ,hessian crucible 7,a1 ,fig4 #hc71 & on top ( x is plac$ a small heap ,b ( a mixture ( sodium p]oxide & alum9ium1 into :i* is /uck a piece ( magnesium ribbon ,c4 ,p[d]$ fluorsp> ,d is plac$ ar\nd ! sodium p]oxide1 aft] :i* ! crucible is set on a pan ( s& & ! magnesium ribbon ignit$4 ,:5 ! flame rea*es ! sodium p]oxide mixture combu/ion ( ! alum9ium beg9s ) almo/ explosive viol5ce1 s t great c>e mu/ be tak5 9 ! exp]im5t4 ,! heat ( ?is combu/ion />ts ! reaction 9 ! *romium oxide mixture1 & ! oxide is r$uc$ to metallic *romium4 ,:5 ! crucible has cool$ a button ( *romium w be f\nd 9 ! bottom4 ,alum9ium oxide 7,al#b,o#c74 ,?is sub/ance occurs 9 sev]al =ms 9 nature4 ,! relatively pure cry/als are call$ corundum1 :ile em]y is a v>iety color$ d>k gray or black1 usually ) iron comp\nds4 ,9 transp>5t cry/als1 t9t$ diff]5t colors by traces ( impurities1 x =ms su* preci\s /ones z ! sapphire1 ori5tal ruby1 topaz1 & ame?y/4 ,all ^! v>ieties are v h>d1 fall+ little %ort ( ! diamond 9 ?is respect4 ,*emically pure alum9ium oxide c be made by ignit+ ! hydroxide1 :5 x =ms an amorph\s :ite p[d]3 #b;,al7,,oh7#c ,al#b,o#c #c;,h#b,o4 ,! natural v>ieties1 corundum & em]y1 are us$ = cutt+ & gr9d+ purposes2 ! pure/ =ms1 toge!r ) ! artificially prep>$ oxide1 are l>gely us$ 9 ! prep>ation ( alum9ium4 ,alum9ium hydroxide 7,al7,,oh7#c74 ,! hydroxide occurs 9 nature z ! m9]al hydr>gyllite1 & 9 a p>tially dehydrat$ =m call$ bauxite4 ,x c be prep>$ by add+ ammonium hydroxide to any soluble alum9ium salt1 =m+ a semi-transp>5t precipitate :i* is insoluble 9 wat] b v h>d to filt]4 ,x dissolves 9 mo/ acids to =m soluble salts1 & 9 ! /rong bases to =m alum9ates1 z indicat$ 9 ! equations ,al7,,oh7#c #c;,h,cl ,al,cl#c #c;,h#b,o1 ,al7,,oh7#c #c,na,o,h ,al7,o,na7#c #c;,h#b,o4 ,x may act1 !re=e1 ei!r z a weak base or z a weak acid1 its action dep5d+ ^u ! "* ( ! sub/ances ) :i* x is 9 contact4 ,:5 heat$ g5tly ! hydroxide loses "p ( its hydrog5 & oxyg5 accord+ to ! equation ,al7,,oh7#c ,al,o,,oh ,h#b,o4 ,?is sub/ance1 ! =mula ( :i* is frequ5tly writt5 ,h,al,o#b1 is a m pron\nc$ acid ?an is ! hydroxide1 & its salts are frequ5tly =m$ :5 alum9ium comp\nds are fus$ ) alkalis4 ,! magnesium salt ,mg7,al,o#b7b is call$ sp9el1 & _m o!r ( its salts1 call$ alum9ates1 are f\nd 9 nature4 ,:5 heat$ /rongly ! hydroxide is *ang$ into oxide1 :i* w n aga9 take up wat] on be+ moi/5$4 ,mordants & dye+4 ,alum9ium hydroxide has ! peculi> prop]ty ( comb9+ ) _m soluble color+ mat]ials & =m+ insoluble products ) !m4 ,on ?is acc\nt x is (t5 us$ z a filt] to remove objectionable colors f wat]4 ,?is prop]ty also leads to its wide use 9 ! dye indu/ry4 ,_m dyes w n adh]e to natural fib]s su* z cotton & wool1 t is1 w n dye fa/4 ,if1 h[ev]1 ! clo? to be dy$ is soak$ 9 a solution ( alum9ium comp\nds & !n treat$ ) ammonia1 ! alum9ium salts :i* h soak$ into ! fib] w be conv]t$ into ! hydroxide1 :i*1 be+ insoluble1 rema9s 9 ! body ( x4 ,if ! fib] is n[ dipp$ into a solution ( ! dye1 ! alum9ium hydroxide comb9es ) ! color mat]ial & fa/5s1 or fixes1 x ^u ! fib]4 ,a sub/ance :i* s]ves ?is purpose is call$ a mordant1 & alum9ium salts1 p>ticul>ly ! acetate1 are us$ 9 ?is way4 ,alum9ium *loride 7,al,cl#cf ,h#b,o74 ,?is sub/ance is prep>$ by dissolv+ ! hydroxide 9 hydro*loric acid & evaporat+ to cry/allization4 ,:5 heat$ x is conv]t$ into ! oxide1 resembl+ magnesium 9 ?is respect3 #b7;,al,cl#cf ,h#b,o7 ,al#b,o#c #f;,h,cl #i;,h#b,o4 ,! anhydr\s *loride1 :i* has "s important uses1 is made by heat+ alum9ium turn+s 9 a curr5t ( *lor9e4 ,alums4 ,alum9ium sulphate c be prep>$ by ! action ( sulphuric acid ^u alum9ium hydroxide4 ,x has ! prop]ty ( comb9+ ) ! sulphates ( ! alkali metals to =m comp\nds call$ alums4 ,?us1 ) potassium sulphate ! reaction is express$ by ! equation ,k#b,,s#d ,al#b7,,s#d7c #bd;,h#b,o #b7,k,al7,,s#d7bab;,h#b,o74 ,"u simil> conditions ammonium sulphate yields ammonium alum3 7,,nh#d7b,,s#d ,al#b7,,s#d7c #bd;,h#b,o #b7,,nh#d;,al7,,s#d7bab;,h#b,o74 ,o!r trival5t sulphates besides alum9ium sulphate c =m simil> comp\nds ) ! alkali sulphates1 & ^! comp\nds are also call$ alums1 ?\gh !y conta9 no alum9ium4 ,!y all cry/allize 9 octah$ra & conta9 twelve molecules ( wat] ( cry/allization4 ,! alums mo/ frequ5tly prep>$ are ! foll[+3 ,potassium alum ,k,al7,,s#d7bab;,h#b,o4 ,ammonium alum ,,nh#d;,al7,,s#d7bab;,h#b,o4 ,ammonium iron alum ,,nh#d;,fe7,,s#d7bab;,h#b,o4 ,potassium *rome alum ,k,cr7,,s#d7bab;,h#b,o4 ,an alum may !re=e be reg>d$ z a comp\nd d]iv$ f two molecules ( sulphuric acid1 9 :i* "o hydrog5 atom has be5 displac$ by ! unival5t alkali atom1 & ! o!r ?ree hydrog5 atoms by an atom ( "o ( ! trival5t metals1 su* z alum9ium1 iron1 or *romium4 ,v l>ge1 well-=m$ cry/als ( an alum c be prep>$ by susp5d+ a small cry/al by a ?read 9 a saturat$ solution ( ! alum1 z %[n 9 ,fig4 #hd4 ,! small cry/al sl[ly gr[s & assumes a v p]fect =m4 ,illu/ration3 ,fig4 #hd ,o!r salts ( alum9ium4 ,:ile alum9ium hydroxide =ms fairly /able salts ) /rong acids1 x is su* a weak base t its salts ) weak acids are readily hydrolyz$4 ,?us1 :5 an alum9ium salt & a soluble c>bonate are br\ght toge!r 9 solution we %\ld expect to h alum9ium c>bonate precipitat$ accord+ to ! equation #c,na#b;,,co#c #b;,al,cl#c ,al#b7;,,co#c7c #f,na,cl4 ,b if x is =m$ at all1 x in/antly beg9s to hydrolyze1 ! products ( ! hydrolysis be+ alum9ium hydroxide & c>bonic acid1 ,al#b7;,,co#c7c #f;,h#b,o #b;,al7,,oh7#c #c;,h#b;,,co#c4 ,simil>ly a soluble sulphide1 in/ead ( precipitat+ alum9ium sulphide 7,al#b,s#c71 precipitates alum9ium hydroxide2 = hydrog5 sulphide is su* a weak acid t ! alum9ium sulphide at fir/ =m$ hydrolyzes at once1 =m+ alum9ium hydroxide & hydrog5 sulphide3 #c,na#b,s #b;,al,cl#c #f;,h#b,o #b;,al7,,oh7#c #f,na,cl #c;,h#b,s4 ,alum bak+ p[d]s4 ,x is because ( ! hydrolysis ( alum9ium c>bonate t alum is us$ z a con/itu5t ( "s bak+ p[d]s4 ,! alum bak+ p[d]s consi/ ( a mixture ( alum & sodium hydrog5 c>bonate4 ,:5 wat] is add$ ! two comp\nds react toge!r1 =m+ alum9ium c>bonate1 :i* hydrolyzes into alum9ium hydroxide & c>bonic acid4 ,! c>bon dioxide f ! latt] escapes ?r\gh ! d\gh & 9 s do+ raises x into a por\s condition1 :i* is ! end s\ght 9 ! use ( a bak+ p[d]4 ,alum9ium silicates4 ,"o ( ! mo/ common con/itu5ts ( rocks is feldsp> 7,k,al,si#c,o#h71 a mix$ salt ( potassium & alum9ium ) ! polysilicic acid 7,h#d,si#c,o#h74 ,"u ! influ5ce ( moi/ure1 c>bon dioxide1 & *anges ( temp]ature ?is sub/ance is con/antly be+ brok5 d[n into soluble potassium comp\nds & hydrat$ alum9ium silicate4 ,?is comp\nd has ! =mula ,al#b,si#b,o#gb;,h#b,o4 ,9 relatively pure condition x is call$ kaol92 9 ! impure /ate1 mix$ ) s& & o!r sub/ances1 x =ms common clay4 ,mica is ano!r v abundant m9]al1 hav+ v>y+ composition1 b be+ ess5tially ( ! =mula ,k,al,si,o#d4 ,s]p5t9e1 talc1 asbe/os1 & me]s*aum are important complex silicates ( alum9ium & magnesium1 & granite is a me*anical mixture ( qu>tz1 feldsp>1 & mica4 ,c]amic indu/ries4 ,_m articles ( greate/ practical importance1 rang+ f ! r\ghe/ brick & tile to ! f9e/ porcela9 & *9aw>e1 are made f "s =m ( kaol91 or clay4 ,no v precise classification ( su* w>e c be made1 z ! products v>y greatly 9 prop]ties1 dep5d+ ^u ! mat]ials us$ & ! treatm5t dur+ manufacture4 ,porcela9 is made f ! pure/ kaol91 to :i* mu/ be add$ "s less pure1 pla/ic kaol91 s9ce ! pure sub/ance is n suffici5tly pla/ic4 ,!re is also add$ "s m fusible sub/ance1 su* z feldsp>1 gypsum1 or lime1 toge!r ) "s pure qu>tz4 ,! con/itu5ts mu/ be gr\nd v f9e1 & :5 ?or\ghly mix$ & moi/5$ mu/ make a pla/ic mass :i* c be mold$ into any desir$ =m4 ,! article mold$ f su* mat]ials is !n burn$4 ,9 ?is process ! article is sl[ly heat$ to a po9t at :i* x beg9s to s(t5 & almo/ fuse1 & !n x is all[$ to cool sl[ly4 ,at ?is /age1 a v ?9 vessel w be transluc5t & h an almo/ glassy fracture2 if1 h[ev]1 x is some:at ?ick]1 or has n be5 heat$ q s high1 x w /ill be por\s1 & p>tly on ?is acc\nt & p>tly to improve its appe>ance x is usually glaz$4 ,glaz+ is accompli%$ by spread+ ^u ! object a ?9 lay] ( a m fusible mixture ( ! same mat]ials z compose ! body ( ! object itself1 & aga9 heat+ until ! glaze melts to a transp>5t glassy coat+ ^u ! surface ( ! vessel4 ,9 "s cases fusible mixtures ( q diff]5t composition f t us$ 9 fa%ion+ ! vessel may be us$ z a glaze4 ,oxides ( lead1 z9c1 & b>ium are (t5 us$ 9 ?is way4 ,:5 less c>efully select$ mat]ials are us$1 or q ?ick vessels are made1 v>i\s grades ( /onew>e are produc$4 ,! inf]ior grades are glaz$ by ?r[+ a quantity ( common salt into ! kiln t[>ds ! end ( ! fir/ fir+4 ,9 ! =m ( vapor ! salt attacks ! surface ( ! bak$ w>e & =ms an easily fusible sodium silicate ^u x1 :i* con/itutes a glaze4 ,vitrifi$ bricks1 made f clay or gr\nd %ale1 are burn$ until ! mat]ials beg9 to fuse sup]ficially1 =m+ _! own glaze4 ,o!r =ms ( brick & tile are n glaz$ at all1 b are left por\s4 ,! r$ color ( ord9>y brick & e>!nw>e is due to an oxide ( iron =m$ 9 ! burn+ process4 ,! decorations ^u *9a are sometimes pa9t$ ^u ! bak$ w>e & !n glaz$ ov]1 & sometimes pa9t$ ^u ! glaze & burn$ 9 by a ?ird fir+4 ,c>e mu/ be tak5 to use su* pigm5ts z are n affect$ by a high heat & d n react *emically ) ! con/itu5ts ( ! bak$ w>e or ! glaze4 ,,ex]cises #a4 ,:at metals & comp\nds /udi$ are prep>$ by electrolysis8 #b4 ,write ! equation = ! reaction betwe5 alum9ium & hydro*loric acid2 betwe5 alum9ium & sulphuric acid 79 two /eps74 #c4 ,:at hydroxides o!r ?an alum9ium hydroxide h bo? acid & basic prop]ties8 #d4 ,write equations %[+ ! me?ods us$ = prep>+ alum9ium hydroxide & sulphate4 #e4 ,write ! g5]al =mula ( an alum1 repres5t+ an atom ( an alkali metal by ,x & an atom ( a trival5t metal by ,y4 #f4 ,:at is meant by ! t]m polysilicic acid1 z us$ 9 ! discussion ( alum9ium silicates8 #g4 ,comp>e ! prop]ties ( ! hydroxides ( ! diff]5t gr\ps ( metals s f> /udi$4 #h4 ,9 :at respects does alum9ium oxide diff] f calcium oxide 9 prop]ties8 #i4 ,suppos+ bauxite to be #ij alum9ium hydroxide1 :at weight ( x is necess>y = ! prep>ation ( #ajj kg4 ( alum9ium8 ,,*apt] ,,xxvii ,,! ,,iron ,,family ,,approximate ,,symbol ,,atomic ,,d5sity ,,melt+ ,,oxides ,,weight ,,po9t ,iron ,fe #ee4i #g4ic #ahjj ,fe,o1 ,fe#b,o#c ,cobalt ,co #ei4j #h4ee #ahjj ,co,o1 ,co#b,o#c ,nickel ,ni #eh4g #h4i #afjj ,ni,o1 ,ni#b,o#c ,! family4 ,! elem5ts iron1 cobalt1 & nickel =m a gr\p 9 ! eigh? column ( ! p]iodic table4 ,! atomic weights ( ! ?ree are v close toge!r1 & !re is n ! same gradual gradation 9 ! prop]ties ( ! ?ree elem5ts t is notic$ 9 ! families 9 :i* ! atomic weights diff] consid]ably 9 magnitude4 ,! elem5ts are v simil> 9 prop]ties1 ! simil>ity be+ s great 9 ! case ( nickel & cobalt t x is difficult to sep>ate !m by *emical analysis4 ,! elem5ts occur 9 nature *iefly z oxides & sulphides1 ?\gh !y h be5 f\nd 9 v small quantities 9 ! native /ate1 usually 9 meteorites4 ,_! sulphides1 c>bonates1 & phosphates are insoluble 9 wat]1 ! o!r common salts be+ soluble4 ,_! salts are usually highly color$1 ^? ( iron be+ yell[ or light gre5 z a rule1 ^? ( nickel d>k] gre51 :ile cobalt salts are usually rose color$4 ,! metals are obta9$ by r$uc+ ! oxides ) c>bon4 ,,iron ,occurr5ce4 ,! elem5t iron has long be5 kn[n1 s9ce its ores are v abundant & x is n difficult to prep>e ! metal f !m 9 fairly pure condition4 ,x occurs 9 nature 9 _m =ms ( comb9ation1--9 l>ge deposits z oxides1 sulphides1 & c>bonates1 & 9 small] quantities 9 a great v>iety ( m9]als4 ,inde$1 v few rocks or soils are free f small am\nts ( iron1 & x is assimilat$ by plants & animals play+ an important "p 9 life processes4 ,metallurgy4 ,x w be conv5i5t to treat ( ! metallurgy ( iron "u two heads1--,mat]ials ,us$ & ,process4 ,mat]ials us$4 ,f\r di/9ct mat]ials are us$ 9 ! metallurgy ( iron3 #a4 ,iron ore4 ,! ores mo/ frequ5tly us$ 9 ! metallurgy ( iron are ! foll[+3 ,hematite ,fe#b,o#c4 ,magnetite ,fe#c,o#d4 ,sid]ite ,fe,c,o#c4 ,limonite #b;,fe#b,o#bc;,h#b,o4 ,^! ores always conta9 impurities1 su* z silica1 sulphides1 & e>?y mat]ials4 ,all ores1 ) ! exception ( ! oxides1 are fir/ roa/$ to expel any wat] & c>bon dioxide pres5t & to conv]t any sulphide into oxide4 #b4 ,c>bon4 ,c>bon 9 "s =m is necess>y bo? z a fuel & z a r$uc+ ag5t4 ,9 =m] times wood *>coal 0 us$ to supply ! c>bon1 b n[ an?racite coal or coke is almo/ univ]sally us$4 #c4 ,hot air4 ,to ma9ta9 ! high temp]ature requir$ = ! r$uction ( iron a v active combu/ion ( fuel is necess>y4 ,?is is secur$ by =c+ a /rong bla/ ( hot air into ! l[] "p ( ! furnace dur+ ! r$uction process4 #d4 ,flux4 7a7 ,purpose ( ! flux4 ,all ! mat]ials :i* ent] ! furnace mu/ leave x aga9 ei!r 9 ! =m ( gases or z liquids4 ,! iron is drawn (f z ! liquid metal aft] its r$uction4 ,to secure ! removal ( ! e>?y matt] *>g$ into ! furnace along ) ! ore1 mat]ials are add$ to ! *>ge :i* w1 at ! high temp]ature ( ! furnace1 comb9e ) ! impurities 9 ! ore1 =m+ a liquid4 ,! mat]ial add$ = ?is purpose is call$ ! flux2 ! liquid produc$ f ! flux & ! ore is call$ slag4 7b7 ,function ( ! slag4 ,:ile ! ma9 purpose ( add+ flux to ! *>ge is to remove f ! furnace 9 ! =m ( liquid slag ! impurities orig9ally pres5t 9 ! ore1 ! slag ?us produc$ s]ves sev]al o!r functions4 ,x keeps ! cont5ts ( ! furnace 9 a /ate ( fusion1 ?us prev5t+ clogg+1 & makes x possible = ! small globules ( iron to run toge!r ) great] ease into "o l>ge liquid mass4 7c7 ,"* ( ! slag4 ,! slag is really a k9d ( readily fusible glass1 be+ ess5tially a calcium-alum9ium silicate4 ,! ore usually conta9s silica & "s alum9ium comp\nds1 s t lime/one 7:i* also conta9s "s silica & alum9ium7 is add$ to furni% ! calcium requir$ = ! slag4 ,if ! ore & ! lime/one d n conta9 a suffici5t am\nt ( silica & alum9ium = ! =mation ( ! slag1 ^! +r$i5ts are add$ 9 ! =m ( s& & feldsp>4 ,9 ! =mation ( slag f ^! mat]ials ! ore is fre$ f ! silica & alum9ium :i* x conta9$4 ,illu/ration3 ,fig4 #he ,process4 ,! r$uction ( iron is c>ri$ out 9 l>ge t[]s call$ bla/ furnaces4 ,! bla/ furnace 7,fig4 #he7 is usually ab\t #hj ft4 high & #bj ft4 9 int]nal diamet] at its wide/ "p1 n>r[+ some:at bo? t[>d ! top & t[>d ! bottom4 ,! walls are built ( /eel & l9$ ) fire-brick4 ,! base is provid$ ) a numb] ( pipes ,t1 call$ tuy]s1 ?r\gh :i* hot air c be =c$ into ! furnace4 ,! tuy]s are suppli$ f a l>ge pipe ,s1 :i* circles ! furnace z a girdle4 ,! base has also an op5+ ,m1 ?r\gh :i* ! liquid metal c be drawn (f f "t to "t1 & a second op5+ ,p1 some:at above ! fir/1 ?r\gh :i* ! excess ( slag ov]fl[s4 ,! top is clos$ by a movable trap ,c & ,c1 call$ ! cone1 & ?r\gh ?is ! mat]ials to be us$ are introduc$4 ,! gases produc$ by ! combu/ion ( ! fuel & ! r$uction ( ! ore1 toge!r ) ! nitrog5 ( ! air =c$ 9 ?r\gh ! tuy]s1 escape ?r\gh pipes ,d1 call$ d[ncom] pipes1 :i* leave ! furnace ne> ! top4 ,^! gases are v hot & conta9 combu/ible sub/ances1 pr9cipally c>bon monoxide2 !y are !re=e utiliz$ z fuel = ! eng9es & also to heat ! bla/ admitt$ ?r\gh ! tuy]s4 ,! l[] "p ( ! furnace is (t5 furni%$ ) a wat] jacket4 ,?is consi/s ( a s]ies ( pipes ,w built into ! walls1 ?r\gh :i* wat] c be circulat$ to r$uce _! temp]ature4 ,*>ges consi/+ ( coke 7or an?racite coal71 ore1 & flux 9 prop] proportions are introduc$ into ! furnace at int]vals ?r\gh ! trap top4 ,! coke burns fi]cely 9 ! hot-air bla/1 giv+ an int5se heat & =m+ c>bon monoxide4 ,! ore1 work+ d[n 9 ! furnace z ! coke burns1 becomes v hot1 & by ! comb9$ r$uc+ action ( ! c>bon & c>bon monoxide is f9ally r$uc$ to metal & collects z a liquid 9 ! bottom ( ! furnace1 ! slag float+ on ! molt5 iron4 ,aft] a consid]able am\nt ( ! iron has collect$ ! slag is drawn (f ?r\gh ! op5+ ,p4 ,! molt5 iron is !n drawn (f into l>ge ladles & tak5 to ! conv]t]s = ! manufacture ( /eel1 or x is run out into s& molds1 =m+ ! b>s or +ots call$ pigs4 ,! process is a cont9u\s "o1 & :5 once />t$ x is kept 9 op]ation = mon?s or ev5 ye>s )\t int]ruption4 ,x seems probable t ! fir/ product ( combu/ion ( ! c>bon1 at ! po9t :]e ! tuy]s ent] ! furnace1 is c>bon dioxide4 ,?is is at once r$uc$ to c>bon monoxide by ! int5sely heat$ c>bon pres5t1 s t no c>bon dioxide c be f\nd at t po9t4 ,= practical purposes1 !re=e1 we may consid] t c>bon monoxide is ! fir/ product ( combu/ion4 ,v>ieties ( iron4 ,! iron ( comm]ce is nev] pure1 b conta9s v>y+ am\nts ( o!r elem5ts1 su* z c>bon1 silicon1 phosphorus1 sulphur1 & manganese4 ,^! elem5ts may ei!r be alloy$ ) ! iron or may be comb9$ ) x 9 ! =m ( def9ite *emical comp\nds4 ,9 "s in/ances1 z 9 ! case ( graphite1 ! mixture may be m]ely me*anical4 ,! prop]ties ( iron are v mu* modifi$ by ! pres5ce ( ^! elem5ts & by ! =m ( ! comb9ation betwe5 !m & ! iron2 ! way 9 :i* ! metal is treat$ dur+ its prep>ation has also a m>k$ influ5ce on its prop]ties4 ,ow+ to ^! facts _m k9ds ( iron are recogniz$ 9 comm]ce1 ! *ief v>ieties be+ ca/ iron1 wr\ght iron1 & /eel4 ,ca/ iron4 ,! product ( ! bla/ furnace1 prep>$ z j describ$1 is call$ ca/ iron4 ,x v>ies consid]ably 9 composition1 usually conta9+ f #ij to #ie iron1 ! rema9d] be+ l>gely c>bon & silicon ) small] am\nts ( phosphorus & sulphur4 ,:5 ! melt$ metal f ! bla/ furnace is all[$ to cool rapidly mo/ ( ! c>bon rema9s 9 *emical comb9ation ) ! iron1 & ! product is call$ :ite ca/ iron4 ,if ! cool+ goes on sl[ly1 ! c>bon p>tially sep>ates z flakes ( graphite :i* rema9 scatt]$ ?r\gh ! metal4 ,?is product is s(t] & d>k] 9 color & is call$ gray ca/ iron4 ,prop]ties ( ca/ iron4 ,ca/ iron is h>d1 brittle1 & r easily melt$ 7melt+ po9t ab\t #aajj74 ,x _c be weld$ or =g$ into %ape1 b is easily ca/ 9 s& molds4 ,x is /rong & rigid b n ela/ic4 ,x is us$ = mak+ ca/+s & 9 ! manufacture ( o!r k9ds ( iron4 ,ca/ iron1 :i* conta9s ! metal manganese up to ! ext5t ( #bj1 toge!r ) ab\t #c c>bon1 is call$ spiegel iron2 :5 m ?an ?is am\nt ( manganese is pres5t ! product is call$ f]romanganese4 ,! f]romanganese may conta9 z mu* z #hj manganese4 ,^! v>ieties ( ca/ iron are mu* us$ 9 ! manufacture ( /eel4 ,wr\ght iron4 ,wr\ght iron is made by burn+ out f ca/ iron mo/ ( ! c>bon1 silicon1 phosphorus1 & sulphur :i* x conta9s4 ,! process is call$ puddl+1 & is c>ri$ out 9 a furnace con/ruct$ z repres5t$ 9 ,fig4 #hf4 ,! floor ( ! furnace ,f is some:at concave & is made ( iron cov]$ ) a lay] ( iron oxide4 ,a long flame produc$ by burn+ fuel ^u ! grate ,g is direct$ d[nw>d ^u ! mat]ials plac$ ^u ! floor1 & ! draught is ma9ta9$ by ! /ack ,s4 ,a is ! a% box & ,t a trap to cat* ! solid p>ticles c>ri$ into ! /ack by ! draught4 ,^u ! floor ( ! furnace is plac$ ! *>ge ( ca/ iron1 toge!r ) a small am\nt ( mat]ial to make a slag4 ,! iron is soon melt$ by ! flame direct$ ^u x1 & ! sulphur1 phosphorus1 & silicon are oxidiz$ by ! iron oxide1 =m+ oxides :i* are anhydrides ( acids4 ,^! comb9e ) ! flux1 :i* is basic 9 "*1 or ) ! iron oxide1 to =m a slag4 ,! c>bon is also oxidiz$ & escapes z c>bon dioxide4 ,z ! iron is fre$ f o!r elem5ts x becomes pa/y1 ow+ to ! high] melt+ po9t ( ! pur] iron1 & 9 ?is condition =ms small lumps :i* are rak$ toge!r into a l>g] "o4 ,! l>ge lump is !n remov$ f ! furnace & roll$ or hamm]$ into b>s1 ! slag2 be+ squeez$ out 9 ?is process4 ,! product has a /r&$ or fibr\s /ructure4 ,! product ( a puddl+ furnace is call$ wr\ght iron4 ,illu/ration3 ,fig4 #hf ,prop]ties ( wr\ght iron4 ,wr\ght iron is ne>ly pure iron1 usually conta9+ ab\t #j4c ( o!r sub/ances1 *iefly c>bon4 ,x is t\gh1 malleable1 & fibr\s 9 /ructure4 ,x is easily b5t & is n ela/ic1 s x w n su/a9 pressure z well z ca/ iron4 ,x c be drawn out into wire ( great t5sile /r5g?1 & c also be roll$ into ?9 %eets 7%eet iron74 ,x melts at a high temp]ature 7ab\t #afjj7 & is !re=e =g$ into %ape r ?an ca/4 ,if melt$1 x w\ld lose its fibr\s /ructure & be *ang$ into a l[ c>bon /eel4 ,/eel4 ,/eel1 l wr\ght iron1 is made by burn+ out f ca/ iron a "p ( ! c>bon1 silicon1 phosphorus1 & sulphur :i* x conta9s2 b ! process is c>ri$ out 9 a v diff]5t way1 & usually1 ?\gh n always1 m c>bon is f\nd 9 /eel ?an 9 wr\ght iron4 ,a numb] ( processes are 9 use1 b ne>ly all ! /eel ( comm]ce is made by "o ( ! two foll[+ me?ods4 ,illu/ration3 ,fig4 #hg #a4 ,bessem] process4 ,?is process1 inv5t$ ab\t #ahfj1 is by f> ! mo/ important4 ,x is c>ri$ out 9 great egg-%ap$ crucibles call$ conv]t]s 7,fig4 #hg71 ea* "o ( :i* w hold z mu* z #ae tons ( /eel4 ,! conv]t] is built ( /eel & l9$ ) silica4 ,x is m\nt$ on trunnions ,t1 s t x c be tipp$ ov] on its side = fill+ & empty+4 ,"o ( ! trunnions is holl[ & a pipe ,p connects x ) an air *amb] ,a1 :i* =ms a false bottom to ! conv]t]4 ,! true bottom is p]=at$1 s t air c be =c$ 9 by an air bla/ admitt$ ?r\gh ! trunnion & ! air *amb]4 ,:ite-hot1 liquid ca/ iron f a bla/ furnace is run into ! conv]t] ?r\gh its op5 necklike top ,o1 ! conv]t] be+ tipp$ ov] to receive x2 ! air bla/ is !n turn$ on & ! conv]t] rotat$ to a ne>ly v]tical position4 ,! elem5ts 9 ! iron are rapidly oxidiz$1 ! silicon fir/ & !n ! c>bon4 ,! heat lib]at$ 9 ! oxidation1 l>gely due to ! combu/ion ( silicon1 keeps ! iron 9 a molt5 condition4 ,:5 ! c>bon is practically all burn$ out ca/ iron or spiegel iron1 conta9+ a kn[n p]c5tage ( c>bon1 is add$ & all[$ to mix ?or\ghly ) ! fluid4 ,! /eel is !n run into molds1 & ! +ots s =m$ are hamm]$ or roll$ into rails or o!r =ms4 ,by ?is process any desir$ p]c5tage ( c>bon c be add$ to ! /eel4 ,l[ c>bon /eel1 :i* does n diff] mu* f wr\ght iron 9 composition1 is n[ made 9 ?is way & is replac+ ! m exp5sive wr\ght iron = _m purposes4 ,! basic l9+ process4 ,:5 ! ca/ iron conta9s phosphorus & sulphur 9 appreciable quantities1 ! l9+ ( ! conv]t] is made ( dolomite4 ,! silicon & c>bon burn1 foll[$ by ! phosphorus & sulphur1 & ! anhydrides ( acids s =m$ comb9e ) ! basic oxides ( ! l9+1 =m+ a slag4 ,?is is kn[n z ! basic l9+ process4 #b4 ,op5-he>? process4 ,9 ?is process a furnace v simil> to a puddl+ furnace is us$1 b x is l9$ ) silica or dolomite in/ead ( iron oxide4 ,a *>ge consi/+ 9 "p ( old scrap iron ( any k9d & 9 "p ( ca/ iron is melt$ 9 ! furnace by a gas flame4 ,! silicon & c>bon are sl[ly burn$ away1 & :5 a te/ %[s t ! desir$ p]c5tage ( c>bon is pres5t ! /eel is run out ( ! furnace4 ,/eel may !re=e be def9$ z ! product ( ! ,bessem] or op5-he>? processes4 ,prop]ties ( /eel4 ,bessem] & op5-he>? /eel usually conta9 only a few t5?s ( a p] c5t ( c>bon1 less ?an #j4a silicon1 & a v mu* small] quantity ( phosphorus & sulphur4 ,any consid]able am\nt ( ! latt] elem5ts makes ! /eel brittle1 ! sulphur affect+ x :5 hot1 & ! phosphorus :5 cold4 ,?is k9d ( /eel is us$ = /ructural purposes1 = rails1 & = ne>ly all l>ge /eel articles4 ,x is h>d1 malleable1 ductile1 & melts at a l[] temp]ature ?an wr\ght iron4 ,x c be =g$ into %ape1 roll$ into %eets1 or ca/ 9 molds4 ,relation ( ! ?ree v>ieties ( iron4 ,x w be se5 t wr\ght iron is usually v ne>ly pure iron1 :ile /eel conta9s an appreciable am\nt ( alloy mat]ial1 *iefly c>bon1 & ca/ iron /ill m ( ! same sub/ances4 ,x is impossible1 h[ev]1 to assign a giv5 sample ( iron to "o ( ^! ?ree classes on ! basis ( its *emical composition alone4 ,a l[ c>bon /eel1 = example1 may conta9 less c>bon ?an a giv5 sample ( wr\ght iron4 ,! real di/9ction betwe5 ! ?ree is ! process by :i* !y are made4 ,! product ( ! bla/ furnace is ca/ iron2 t ( ! puddl+ furnace is wr\ght iron2 t ( ! ,bessem] & op5-he>? me?ods is /eel4 ,tool /eel4 ,/eel design$ = use 9 ! manufacture ( edg$ tools & simil> articles %\ld be relatively free f silicon & phosphorus1 b %\ld conta9 f #j4e to #a4e c>bon4 ,! p]c5tage ( c>bon %\ld be regulat$ by ! exact use to :i* ! /eel is to be put4 ,/eel ( ?is "* is usually made 9 small lots f ei!r ,bessem] or op5-he>? /eel 9 ! foll[+ way4 ,a *>ge ( melt$ /eel is plac$ 9 a l>ge crucible & ! calculat$ quantity ( pure c>bon is add$4 ,! c>bon dissolves 9 ! /eel1 & :5 ! solution is complete ! metal is p\r$ out ( ! crucible4 ,?is is sometimes call$ crucible /eel4 ,temp]+ ( /eel4 ,/eel conta9+ f #j4e to #a4e c>bon is *>act]iz$ by ! prop]ty ( tak+ temp]4 ,:5 ! hot /eel is sudd5ly cool$ by plung+ x into wat] or oil x becomes v h>d & brittle4 ,on c>efully reheat+ ?is h>d =m x gradually becomes less brittle & s(t]1 s t by regulat+ ! temp]ature to :i* /eel is reheat$ 9 temp]+ almo/ any condition ( temp] dem&$ = a giv5 purpose1 su* z = mak+ spr+s or cutt+ tools1 c be obta9$4 ,/eel alloys4 ,x has be5 f\nd t small quantities ( a numb] ( diff]5t elem5ts :5 alloy$ ) /eel v mu* improve its quality = c]ta9 purposes1 ea* elem5t hav+ a some:at diff]5t effect4 ,among ! elem5ts mo/ us$ 9 ?is connection are manganese1 silicon1 *romium1 nickel1 tung/51 & molybd5um4 ,! usual me?od = add+ ^! elem5ts to ! /eel is to fir/ prep>e a v ri* alloy ( iron ) ! elem5t to be add$1 & !n add en\gh ( ?is alloy to a l>ge quantity ( ! /eel to br+ x to ! desir$ composition4 ,a ri* alloy ( iron ) manganese or silicon c be prep>$ directly 9 a bla/ furnace1 & is call$ f]romanganese or f]rosilicon4 ,simil> alloys ( iron ) ! o!r elem5ts m5tion$ are made 9 an electric furnace by r$uc+ ! mix$ oxides ) c>bon4 ,pure iron4 ,p]fectly pure iron is r>ely prep>$ & is n adapt$ to comm]cial uses4 ,x c be made by r$uc+ pure oxide ( iron 9 a curr5t ( hydrog5 at a high temp]ature4 ,prep>$ 9 ?is way x =ms a black p[d]2 :5 melt$ x =ms a t9-:ite metal :i* is less fusible & m malleable ?an wr\ght iron4 ,x is easily act$ ^u by moi/ air4 ,comp\nds ( iron4 ,iron diff]s f ! metals s f> /udi$ 9 t x is able to =m two s]ies ( comp\nds 9 :i* ! iron has two diff]5t val5ces4 ,9 ! "o s]ies ! iron is dival5t & =ms comp\nds :i* 9 =mulas & _m *emical prop]ties are simil> to ! correspond+ z9c comp\nds4 ,x c also act z a trival5t metal1 & 9 ?is condition =ms salts simil> to ^? ( alum9ium4 ,^? comp\nds 9 :i* ! iron is dival5t are kn[n z f]r\s comp\nds1 :ile ^? 9 :i* x is trival5t are kn[n z f]ric4 ,oxides ( iron4 ,iron =ms sev]al oxides4 ,f]r\s oxide 7,fe,o7 is n f\nd 9 nature1 b c be prep>$ artificially 9 ! =m ( a black p[d] :i* easily takes up oxyg51 =m+ f]ric oxide3 #b;,fe,o ,o ,fe#b,o#c4 ,f]ric oxide is ! mo/ abundant ore ( iron & occurs 9 great deposits1 especially 9 ! ,lake ,sup]ior region4 ,x is f\nd 9 _m m9]al v>ieties :i* v>y 9 d5sity & color1 ! mo/ abundant be+ hematite1 :i* ranges 9 color f r$ to ne>ly black4 ,:5 prep>$ by *emical processes x =ms a r$ p[d] :i* is us$ z a pa9t pigm5t 7,v5etian r$7 & z a poli%+ p[d] 7r\ge74 ,magnetite has ! =mula ,fe#c,o#d & is a comb9ation ( ,fe,o & ,fe#b,o#c4 ,x is a v valuable ore1 b is less abundant ?an hematite4 ,x is sometimes call$ magnetic oxide ( iron1 or lode/one1 s9ce x is a natural magnet4 ,f]r\s salts4 ,^! salts are obta9$ by dissolv+ iron 9 ! appropriate acid1 or1 :5 insoluble1 by precipitation4 ,!y are usually light gre5 9 color & cry/allize well4 ,9 *emical reactions !y are q simil> to ! salts ( magnesium & z9c1 b diff] f !m 9 "o important respect1 namely1 t !y are easily *ang$ into comp\nds 9 :i* ! metal is trival5t4 ,?us f]r\s *loride treat$ ) *lor9e or aqua regia is *ang$ into f]ric *loride3 ,fe,cl#b ,cl ,fe,cl#c4 ,f]r\s hydroxide expos$ to moi/ air is rapidly *ang$ into f]ric hydroxide3 #b;,fe7,,oh7#b ,h#b,o ,o #b;,fe7,,oh7#c4 ,f]r\s sulphate 7copp]as1 gre5 vitriol7 7,fe,s,o#dg;,h#b,o74 ,f]r\s sulphate is ! mo/ famili> f]r\s comp\nd4 ,x is prep>$ comm]cially z a by-product 9 ! /eel-plate mills4 ,/eel plates are clean$ by ! action ( dilute sulphuric acid ^u !m1 & 9 ! process "s ( ! iron dissolves4 ,! liquors are conc5trat$ & ! gre5 vitriol sep>ates f !m4 ,f]r\s sulphide 7,fe,s74 ,f]r\s sulphide is sometimes f\nd 9 nature z a gold5-yell[ cry/all9e m9]al4 ,x is =m$ z a black precipitate :5 a soluble sulphide & an iron salt are br\ght toge!r 9 solution3 ,fe,s,o#d ,na#b,s ,fe,s ,na#b,,s#d4 ,x c also be made z a heavy d>k-br[n solid by fus+ toge!r ! requisite quantities ( sulphur & iron4 ,x is obta9$ z a by-product 9 ! metallurgy ( lead3 ,pb,s ,fe ,fe,s ,pb4 ,x is us$ 9 ! laboratory 9 ! prep>ation ( hydrosulphuric acid3 ,fe,s #b;,h,cl ,fe,cl#b ,h#b,s4 ,iron disulphide 7pyrites7 7,fe,s#b74 ,?is sub/ance be>s ! same relation to f]r\s sulphide t hydrog5 dioxide does to wat]4 ,x occurs abundantly 9 nature 9 ! =m ( brass-yell[ cubical cry/als & 9 compact masses4 ,sometimes ! "n fool's gold is appli$ to x f its sup]ficial resemblance to ! preci\s metal4 ,x is us$ 9 v l>ge quantities z a s\rce ( sulphur dioxide 9 ! manufacture ( sulphuric acid1 s9ce x burns readily 9 ! air1 =m+ f]ric oxide & sulphur dioxide3 #b;,fe,s#b #aa,o ,fe#b,o#c #d,,s#b4 ,f]r\s c>bonate 7,fe,c,o#c74 ,?is comp\nd occurs 9 nature z sid]ite1 & is a valuable ore4 ,x w dissolve to "s ext5t 9 wat] conta9+ c>bon dioxide1 j z w calcium c>bonate1 & wat]s conta9+ x are call$ *alybeate wat]s4 ,^! *alybeate wat]s are suppos$ to possess c]ta9 m$ic9al virtues & =m an important class ( m9]al wat]s4 ,f]ric salts4 ,f]ric salts are usually obta9$ by treat+ an acidifi$ solution ( a f]r\s salt ) an oxidiz+ ag5t3 #b;,fe,cl#b #b;,h,cl ,o #b;,fe,cl#c ,h#b,o1 #b;,fe,s,o#d ,h#b,,s#d ,o ,fe#b7,,s#d7c ,h#b,o4 ,!y are usually yell[ or violet 9 color1 are q soluble1 & z a rule d n cry/allize well4 ,heat$ ) wat] 9 ! abs5ce ( free acid1 !y hydrolyze ev5 m readily ?an ! salts ( alum9ium4 ,! mo/ famili> f]ric salts are ! *loride & ! sulphate4 ,f]ric *loride 7,fe,cl#c74 ,?is salt c be obta9$ mo/ conv5i5tly by dissolv+ iron 9 hydro*loric acid & !n pass+ *lor9e into ! solution3 ,fe #b;,h,cl ,fe,cl#b #b;,h1 ,fe,cl#b ,cl ,fe,cl#c4 ,:5 ! pure salt is heat$ ) wat] x is p>tly hydrolyz$3 ,fe,cl#c #c ,h#b,o -- ,fe7,,oh7#c #c;,h,cl4 ,?is is a rev]sible reaction1 h[ev]1 & hydrolysis c !re=e be prev5t$ by fir/ add+ a consid]able am\nt ( ! soluble product ( ! reaction1 namely1 hydro*loric acid4 ,f]ric sulphate 7,fe#b7,,s#d7c74 ,?is comp\nd c be made by treat+ an acid solution ( gre5 vitriol ) an oxidiz+ ag5t4 ,x is difficult to cry/allize & h>d to obta9 9 pure condition4 ,:5 an alkali sulphate 9 prop] quantity is add$ to f]ric sulphate 9 solution an iron alum is =m$1 & is easily obta9$ 9 l>ge cry/als4 ,! be/ kn[n iron alums h ! =mulas ,k,fe7,,s#d7bab;,h#b,o & ,,nh#d;,fe7,,s#d7bab;,h#b,o4 ,!y are commonly us$ :5 a pure f]ric salt is requir$4 ,f]ric hydroxide 7,fe7,,oh7#c74 ,:5 solutions ( f]ric salts are treat$ ) ammonium hydroxide1 f]ric hydroxide is =m$ z a ru/y-r$ precipitate1 insoluble 9 wat]4 ,iron cyanides4 ,a l>ge numb] ( complex cyanides conta9+ iron are kn[n1 ! mo/ important be+ potassium f]rocyanide1 or yell[ prussiate ( pota% 7,k#d;,fe,c#f,n#f71 & potassium f]ricyanide1 or r$ prussiate ( pota% 7,k#c;,fe,c#f,n#f74 ,^! comp\nds are ! potassium salts ( ! complex acids ( ! =mulas ,h#d;,fe,c#f,n#f & ,h#c;,fe,c#f,n#f4 ,oxidation ( f]r\s salts4 ,x has j be5 se5 t :5 a f]r\s salt is treat$ ) an oxidiz+ ag5t 9 ! pres5ce ( a free acid a f]ric salt is =m$3 #b;,fe,s,o#d ,h#b,,s#d ,o ,fe#b7,,s#d7c ,h#b,o4 ,9 ?is reaction oxyg5 is us$ up1 & ! val5ce ( ! iron is *ang$ f #b to #c4 ,! same equation may be writt5 #b;,fe1 #b,,s#d-- #b;,h1 ,,s#d-- ,o #b;,fe1 #c,,s#d-- ,h#b,o4 ,hydrog5 ions h be5 oxidiz$ to wat]1 :ile ! *>ge ( ea* iron ion has be5 increas$ f #b to #c4 ,9 a simil> way ! conv]sion ( f]r\s *loride into f]ric *loride may be writt5 ,fe1 #b;,cl- ,cl ,fe1 #c;,cl-4 ,"h aga9 ! val5ce ( ! iron & ! *>ge on ! iron ion has be5 increas$ f #b to #c1 ?\gh no oxyg5 has ent]$ into ! reaction4 ,z a rule1 h[ev]1 *anges ( ?is k9d are br\ght ab\t by ! use ( an oxidiz+ ag5t1 & are call$ oxidations4 ,! t]m oxidation is appli$ to all reactions 9 :i* ! val5ce ( ! metal ( a comp\nd is increas$1 or1 9 o!r words1 to all reactions 9 :i* ! *>ge ( a cation is increas$4 ,r$uction ( f]ric salts4 ,! *anges :i* take place :5 a f]ric salt is conv]t$ into a f]r\s salt are ! rev]se ( ! ones j describ$4 ,?is is se5 9 ! equation ,fe,cl#c ,h ,fe,cl#b ,h,cl ,9 ?is reaction ! val5ce ( ! iron has be5 *ang$ f #c to #b4 ,! same equation may be writt5 ,fe1 #c;,cl- ,h ,fe1 ,h #c;,cl- ,x w be se5 t ! *>ge ( ! iron ions has be5 dim9i%$ f #c to #b4 ,s9ce ^! *anges are ! rev]se ( ! oxidation *anges j consid]$1 !y are call$ r$uction reactions4 ,! t]m r$uction is appli$ to all processes 9 :i* ! val5ce ( ! metal ( a comp\nd is dim9i%$1 or1 9 o!r words1 to all processes 9 :i* ! *>ge on ! cations is dim9i%$4 ,,nickel ,,& ,,cobalt ,^! elem5ts occur sp>+ly 9 nature1 usually comb9$ ) ars5ic or ) ars5ic & sulphur4 ,bo? elem5ts h be5 f\nd 9 ! free /ate 9 meteorites4 ,l iron !y =m two s]ies ( comp\nds1 b ! salts correspond+ to ! f]r\s salts are ! mo/ common1 ! ones correspond+ to ! f]ric salts be+ difficult to obta94 ,?us we h ! *lorides ,ni,cl#bf;,h#b,o & ,co,cl#bf;,h#b,o2 ! sulphates ,ni,s,o#dg;,h#b,o & ,co,s,o#dg;,h#b,o2 ! nitrates ,ni7,,no#c7bf;,h#b,o & ,co7,,no#c7bf;,h#b,o4 ,nickel is l>gely us$ z an alloy ) o!r metals4 ,alloy$ ) copp] x =ms co9 metal f :i* five-c5t pieces are made1 ) copp] & z9c x =ms ,g]man silv]1 & :5 add$ to /eel 9 small quantities nickel /eel is =m$ :i* is mu* sup]ior to common /eel = c]ta9 purposes4 ,:5 deposit$ by electrolysis ^u ! surface ( o!r metals su* z iron1 x =ms a cov]+ :i* w take a high poli% & protects ! metal f ru/1 nickel n be+ act$ ^u by moi/ air4 ,salts ( nickel are usually gre54 ,comp\nds ( cobalt fus$ ) glass give x an int5sely blue color4 ,9 p[d]$ =m su* glass is sometimes us$ z a pigm5t call$ smalt4 ,cobalt salts1 :i* conta9 wat] ( cry/allization1 are usually *]ry r$ 9 color2 :5 dehydrat$ !y become blue4 ,,ex]cises #a4 ,9 ! manufacture ( ca/ iron1 :y is ! air heat$ be=e be+ =c$ into ! furnace8 #b4 ,write ! equations %[+ h[ ea* ( ! foll[+ comp\nds ( iron c\ld be obta9$ f ! metal itself3 f]r\s *loride1 f]r\s hydroxide1 f]r\s sulphate1 f]r\s sulphide1 f]r\s c>bonate1 f]ric *loride1 f]ric sulphate1 f]ric hydroxide4 #c4 ,acc\nt = ! fact t a solution ( sodium c>bonate1 :5 add$ to a solution ( a f]ric salt1 precipitates an hydroxide & n a c>bonate4 #d4 ,calculate ! p]c5tage ( iron 9 ea* ( ! common iron ores4 #e4 ,"o ton ( /eel prep>$ by ! ,bessem] process is f\nd by analysis to conta9 #j4b c>bon4 ,:at is ! m9imum weight ( c>bon :i* mu/ be add$ 9 ord] t ! /eel may be made to take a temp]8 ,,*apt] ,,xxviii ,,copp]1 ,,m]cury1 ,,& ,,silv] ,,=mulas ,,( ,,oxides ,,symbol ,,atomic ,,d5sity ,,melt+ ,,weight ,,po9t ous ic ,copp] ,cu #fc4f #h4hi #ajhd ,cu#b,o ,cu,o ,m]cury ,hg #bjj4jj #ac4eif -#ci4e ,hg#b,o ,hg,o ,silv] ,ag #ajg4ic #aj4e #ifj ,ag#b,o ,ag,o ,! family4 ,by ref]r+ to ! p]iodic arrangem5t ( ! elem5ts 7page #afh71 x w be se5 t m]cury is n includ$ 9 ! same family ) copp] & silv]4 ,s9ce ! metallurgy ( ! ?ree elem5ts is s simil>1 h[ev]1 & s9ce !y resemble ea* o!r s closely 9 *emical prop]ties1 x is conv5i5t to class !m toge!r = /udy4 #a4 ,occurr5ce4 ,! ?ree elem5ts occur 9 nature to "s ext5t 9 ! free /ate1 b are usually f\nd z sulphides4 ,_! ores are easy to r$uce4 #b4 ,prop]ties4 ,!y are heavy metals ( high lu/] & are especially good conductors ( heat & electricity4 ,!y are n v active *emically4 ,nei!r hydro*loric nor dilute sulphuric acid has any appreciable action ^u !m4 ,conc5trat$ sulphuric acid attacks all ?ree1 =m+ metallic sulphates & evolv+ sulphur dioxide1 :ile nitric acid1 bo? dilute & conc5trat$1 conv]ts !m into nitrates ) ! evolution ( oxides ( nitrog54 #c4 ,two s]ies ( salts4 ,copp] & m]cury =m oxides ( ! types ,m#b,o & ,,mo1 z well z two s]ies ( salts4 ,9 "o s]ies ! metals are unival5t & ! salts h =mulas l ^? ( ! sodium salts4 ,!y are call$ cupr\s & m]cur\s salts4 ,9 ! o!r s]ies ! metals are dival5t & resemble magnesium salts 9 =mulas4 ,^! are call$ cupric & m]curic salts4 ,silv] =ms only "o s]ies ( salts1 be+ always a unival5t metal4 ,,copp] ,occurr5ce4 ,! elem5t copp] has be5 us$ = v>i\s purposes s9ce ! e>lie/ days ( hi/ory4 ,x is (t5 f\nd 9 ! metallic /ate 9 nature1 l>ge masses ( x occurr+ pure 9 ! ,lake ,sup]ior region & 9 o!r places to a small] ext5t4 ,! mo/ valuable ores are ! foll[+3 ,cuprite ,cu#b,o4 ,*alcocite ,cu#b,s4 ,*alcopyrite ,cu,fe,s#b4 ,bornite ,cu#c;,fe,s#c4 ,mala*ite ,cu,c,o#c;,cu7,,oh7#b4 ,azurite #b;,cu,c,o#c;,cu7,,oh7#b4 ,metallurgy ( copp]4 ,ores conta9+ little or no sulphur are easy to r$uce4 ,!y are fir/ cru%$ & ! e>?y impurities wa%$ away4 ,! conc5trat$ ore is !n mix$ ) c>bon & heat$ 9 a furnace1 metallic copp] result+ f ! r$uction ( ! copp] oxide by ! hot c>bon4 ,metallurgy ( sulphide ores4 ,mu* ( ! copp] ( comm]ce is made f *alcopyrite & bornite1 & ^! ores are m difficult to "w4 ,!y are fir/ roa/$ 9 ! air1 by :i* treatm5t mu* ( ! sulphur is burn$ to sulphur dioxide4 ,! roa/$ ore is !n melt$ 9 a small bla/ furnace or 9 an op5 "o l a puddl+ furnace4 ,9 melt+1 "p ( ! iron comb9es ) silica to =m a slag ( iron silicate4 ,! product1 call$ crude matte1 conta9s ab\t #ej copp] toge!r ) sulphur & iron4 ,fur!r purification is commonly c>ri$ on by a process v simil> to ! ,bessem] process = /eel4 ,! conv]t] is l9$ ) silica1 & a *>ge ( matte f ! melt+ furnace1 toge!r ) s&1 is introduc$1 & air is bl[n into ! mass4 ,by ?is means ! sulphur is practically all burn$ out by ! air1 & ! rema9+ iron comb9es ) silica & goes (f z slag4 ,! copp] is p\r$ out ( ! conv]t] & mold$ into anode plates = ref9+4 ,ref9+ ( copp]4 ,impure copp] is purifi$ by electrolysis4 ,a l>ge plate ( x1 s]v+ z an anode1 is susp5d$ 9 a tank fac+ a ?9 plate ( pure copp]1 :i* is ! ca?ode4 ,! tank is fill$ ) a solution ( copp] sulphate & sulphuric acid to s]ve z ! electrolyte4 ,a curr5t f a dynamo passes f ! anode to ! ca?ode1 & ! copp]1 dissolv+ f ! anode1 is deposit$ ^u ! ca?ode 9 pure =m1 :ile ! impurities collect on ! bottom ( ! tank4 ,electrolytic copp] is "o ( ! pure/ ( comm]cial metals & is v ne>ly pure copp]4 ,recov]y ( gold & silv]4 ,gold & silv] are (t5 pres5t 9 small quantities 9 copp] ores1 & 9 electrolytic ref9+ ^! metals collect 9 ! muddy deposit on ! bottom ( ! tank4 ,! mud is c>efully work$ ov] f "t to "t & ! preci\s metals extract$ f x4 ,a surpris+ am\nt ( gold & silv] is obta9$ 9 ?is way4 ,prop]ties ( copp]4 ,copp] is a r heavy metal ( d5sity #h4i1 & has a *>act]i/ic r$di% color4 ,x is r s(t & is v malleable1 ductile1 & flexible1 yet t\gh & /rong2 x melts at #ajhd4 ,z a conductor ( heat & electrical en]gy x is second only to silv]4 ,hydro*loric acid1 dilute sulphuric acid1 & fus$ alkalis are almo/ )\t action ^u x2 nitric acid & hot1 conc5trat$ sulphuric acid1 h[ev]1 readily dissolve x4 ,9 moi/ air x sl[ly becomes cov]$ ) a ?9 lay] ( gre5 basic c>bonate2 heat$ 9 ! air x is easily oxidiz$ to black copp] oxide 7,cu,o74 ,uses4 ,copp] is ext5sively us$ = electrical purposes1 = ro(s & cornices1 = %ea?+ ! bottom ( %ips1 & = mak+ alloys4 ,9 ! foll[+ table ! composition ( "s ( ^! alloys is indicat$3 ,,composition ,,( ,,alloys ,,( ,,copp] ,,9 ,,p]c5tages ,alum9ium bronze copp] 7#ij to #ig71 alum9ium 7#c to #aj74 ,brass copp] 7#fc to #gc71 z9c 7#bg to #cg74 ,bronze copp] 7#gj to #ie71 z9c 7#a to #be71 t9 7#a to #ah74 ,g]man silv] copp] 7#ef to #fj71 z9c 7#bj71 nickel 7#bj to #be74 ,gold co9 copp] 7#aj71 gold 7#ij74 ,gun metal copp] 7#ij71 t9 7#aj74 ,nickel co9 copp] 7#ge71 nickel 7#be7 ,silv] co9 copp] 7#aj71 silv] 7#ij74 ,electrotyp+4 ,matt] is (t5 pr9t$ f electrotype plates :i* are prep>$ z foll[s4 ,! matt] is set up 9 type & wax is firmly press$ d[n ^u ! face ( x until a cle> impression is obta9$4 ,! impress$ side ( ! wax is coat$ ) graphite & ! impression is made ! ca?ode 9 an electrolytic cell conta9+ a copp] salt 9 solution4 ,:5 connect$ ) a curr5t ! copp] is deposit$ z a ?9 %eet ^u ! lett]s 9 wax1 & :5 deta*$ is a p]fect copy ( ! type1 ! "u "p ( ! lett]s be+ holl[4 ,! %eet is /r5g!n$ by p\r+ on ! "u surface a suitable am\nt ( molt5 metal 7comm]cial lead is us$74 ,! %eet s /r5g!n$ is !n us$ 9 pr9t+4 ,two s]ies ( copp] comp\nds4 ,copp]1 l iron1 =ms two s]ies ( comp\nds3 9 ! cupr\s comp\nds x is unival5t2 9 ! cupric x is dival5t4 ,! cupric salts are mu* ! m common ( ! two1 s9ce ! cupr\s salts pass readily into cupric by oxidation4 ,cupr\s comp\nds4 ,! mo/ important cupr\s comp\nd is ! oxide 7,cu#b,o71 :i* occurs 9 nature z ruby copp] or cuprite4 ,x is a bright r$ sub/ance & c easily be prep>$ by heat+ copp] to a high temp]ature 9 a limit$ supply ( air4 ,x is us$ = imp>t+ a ruby color to glass4 ,by treat+ cupr\s oxide ) diff]5t acids a numb] ( cupr\s salts c be made4 ,_m ( ^! are insoluble 9 wat]1 ! *loride 7,cu,cl7 be+ ! be/ kn[n4 ,:5 susp5d$ 9 dilute hydro*loric acid x is *ang$ into cupric *loride1 ! oxyg5 tak+ "p 9 ! reaction be+ absorb$ f ! air3 #b;,cu,cl #b;,h,cl ,o #b;,cu,cl#b ,h#b,o4 ,cupric comp\nds4 ,cupric salts are easily made by dissolv+ cupric oxide 9 acids1 or1 :5 insoluble1 by precipitation4 ,mo/ ( !m are blue or gre5 9 color1 & ! soluble ones cry/allize well4 ,s9ce !y are s mu* m famili> ?an ! cupr\s salts1 !y are frequ5tly call$ m]ely copp] salts4 ,cupric oxide 7,cu,o74 ,?is is a black insoluble sub/ance obta9$ by heat+ copp] 9 excess ( air1 or by ignit+ ! hydroxide or nitrate4 ,x is us$ z an oxidiz+ ag5t4 ,cupric hydroxide 7,cu7,,oh7#b74 ,! hydroxide prep>$ by treat+ a solution ( a copp] salt ) sodium hydroxide is a light blue insoluble sub/ance :i* easily loses wat] & *anges into ! oxide4 ,heat appli$ to ! liquid conta9+ ! hydroxide susp5d$ 9 x s]ves to br+ ab\t ! reaction repres5t$ by ! equation ,cu7,,oh7#b ,cu,o ,h#b,o4 ,cupric sulphate 7blue vitriol7 7,cu,s,o#de;,h#b,o74 ,?is sub/ance1 call$ blue vitriol or blue/one1 is obta9$ z a by-product 9 a numb] ( processes & is produc$ 9 v l>ge quantities4 ,x =ms l>ge blue cry/als1 :i* lose wat] :5 heat$ & crumble to a :ite p[d]4 ,! salt f9ds _m uses1 especially 9 electrotyp+ & 9 mak+ electrical batt]ies4 ,cupric sulphide 7,cu,s74 ,! insoluble black sulphide 7,cu,s7 is easily prep>$ by ! action ( hydrosulphuric acid ^u a solution ( a copp] salt3 ,cu,s,o#d ,h#b,s ,cu,s ,h#b,,s#d4 ,x is insoluble 9 wat] & dilute acids4 ,,m]cury ,occurr5ce4 ,m]cury occurs 9 nature *iefly z ! sulphide 7,hg,s7 call$ c9nab>1 & 9 globules ( metal inclos$ 9 ! c9nab>4 ,! m]cury m9es ( ,spa9 h long be5 fam\s1 ,cali=nia be+ ! next l>ge/ produc]4 ,metallurgy4 ,m]cury is a volatile metal :i* has b little aff9ity = oxyg54 ,sulphur1 on ! o!r h&1 readily comb9es ) oxyg54 ,^! facts make ! metallurgy ( m]cury v simple4 ,! cru%$ ore1 mix$ ) a small am\nt ( c>bon to r$uce any oxide or sulphate t might be =m$1 is roa/$ 9 a curr5t ( air4 ,! sulphur burns to sulphur dioxide1 :ile ! m]cury is conv]t$ into vapor & is cond5s$ 9 a s]ies ( cond5s+ vessels4 ,! metal is purifi$ by di/illation4 ,prop]ties4 ,m]cury is a heavy silv]y liquid ) a d5sity ( #ac4eif4 ,x boils at #ceg & solidifies at -#ci4e4 ,small quantities ( _m metals dissolve 9 x1 =m+ liquid alloys1 :ile ) l>g] quantities x =ms solid alloys4 ,! alloys ( m]cury are call$ amalgams4 ,t[>d acids m]cury conducts itself v mu* l copp]2 x is easily attack$ by nitric & hot1 conc5trat$ sulphuric acids1 :ile cold sulphuric & hydro*loric acids h no effect on x4 ,uses4 ,m]cury is ext5sively us$ 9 ! con/ruction ( sci5tific in/rum5ts1 su* z ! !rmomet] & b>omet]1 & z a liquid ov] :i* to collect gases :i* are soluble 9 wat]4 ,! read9ess ) :i* x alloys ) silv] & gold makes x v useful 9 ! extraction ( ^! elem5ts4 ,comp\nds ( m]cury4 ,l copp]1 m]cury =ms two s]ies ( comp\nds3 ! m]cur\s1 ( :i* m]cur\s *loride 7,hg,cl7 is an example2 & ! m]curic1 repres5t$ by m]curic *loride 7,hg,cl#b74 ,m]curic oxide 7,hg,o74 ,m]curic oxide c be obta9$ ei!r z a brick-r$ or z a yell[ sub/ance4 ,:5 m]curic nitrate is heat$ c>efully ! r$ modification is =m$ 9 accordance ) ! equation ,hg7,,no#c7b ,hg,o #b,,no#b ,o4 ,! yell[ modification is prep>$ by add+ a solution ( a m]curic salt to a solution ( sodium or potassium hydroxide3 ,hg7,,no#c7b #b,na,o,h #b,na,n,o#c ,hg7,,oh7#b1 ,hg7,,oh7#b ,hg,o ,h#b,o4 ,:5 heat$ ! oxide d>k5s until x becomes almo/ black2 at a high] temp]ature x decomposes into m]cury & oxyg54 ,x 0 by ?is reaction t oxyg5 0 discov]$4 ,m]cur\s *loride 7calomel7 7,hg,cl74 ,be+ insoluble1 m]cur\s *loride is precipitat$ z a :ite solid :5 a soluble *loride is add$ to a solution ( m]cur\s nitrate3 ,hg,n,o#c ,na,cl ,hg,cl ,na,n,o#c4 ,comm]cially x is manufactur$ by heat+ a mixture ( m]curic *loride & m]cury4 ,:5 expos$ to ! light x sl[ly *anges into m]curic *loride & m]cury3 #b;,hg,cl ,hg,cl#b ,hg4 ,x is !re=e protect$ f ! light by ! use ( color$ bottles4 ,x is us$ 9 m$ic9e4 ,mo/ m]cur\s salts are insoluble 9 wat]1 ! pr9cipal soluble "o be+ ! nitrate1 :i* is made by ! action ( cold1 dilute nitric acid on m]cury4 ,m]curic *loride 7corrosive sublimate7 7,hg,cl#b74 ,?is sub/ance c be made by dissolv+ m]curic oxide 9 hydro*loric acid4 ,on a comm]cial scale x is made by sublim+ a mixture ( common salt & m]curic sulphate3 #b,na,cl ,hg,s,o#d ,hg,cl#b ,na#b,,s#d4 ,! m]curic *loride1 be+ readily volatile1 vaporizes & is cond5s$ aga9 9 cool vessels4 ,l m]cur\s *loride x is a :ite solid1 b diff]s f x 9 t x is soluble 9 wat]4 ,x is extremely poison\s & 9 dilute solutions is us$ z an antiseptic 9 dress+ w\nds4 ,m]curic sulphide 7,hg,s74 ,z c9nab> ?is sub/ance =ms ! *ief native comp\nd ( m]cury1 occurr+ 9 r$ cry/all9e masses4 ,by pass+ hydrosulphuric acid into a solution ( a m]curic salt x is precipitat$ z a black p[d]1 insoluble 9 wat] & acids4 ,by o!r means x c be prep>$ z a brilliant r$ p[d] kn[n z v]milion1 :i* is us$ z a pigm5t 9 f9e pa9ts4 ,! iodides ( m]cury4 ,if a solution ( potassium iodide is add$ to solutions ( a m]cur\s & a m]curic salt respectively1 ! correspond+ iodides are precipitat$4 ,m]curic iodide is ! m important ( ! two1 & z prep>$ above is a r$ p[d] :i* *anges to yell[ on heat+ to #aej4 ,! yell[ =m on cool+ *anges back aga9 to ! r$ =m1 or may be made to d s by rubb+ x ) a knife blade or "s o!r h>d object4 ,,silv] ,occurr5ce4 ,silv] is f\nd 9 small quantities 9 ! uncomb9$ /ate2 usually1 h[ev]1 x occurs 9 comb9ation ) sulphur1 ei!r z ! sulphide 7,ag#b,s7 or z a small con/itu5t ( o!r sulphides1 especially ^? ( lead & copp]4 ,x is also f\nd alloy$ ) gold4 ,metallurgy4 ,p>kes's process4 ,silv] is usually smelt$ 9 connection ) lead4 ,! ores are work$ ov] toge!r1 z describ$ "u lead1 & ! lead & silv] obta9$ z an alloy1 ! silv] be+ pres5t 9 small quantity4 ,! alloy is melt$ & metallic z9c is /irr$ 94 ,z9c w alloy ) silv] b n ) lead1 & x is f\nd t ! silv] leaves ! lead &1 9 ! =m ( an alloy ) z9c1 =ms z a cru/ ^u ! lead & is skimm$ (f4 ,?is cru/1 :i*1 ( c\rse1 conta9s lead adh]+ to x1 is p>tially melt$ & ! mo/ ( ! lead dra9$ (f4 ,! z9c is remov$ by di/illation1 & ! residue is melt$ on an op5 he>? 9 a curr5t ( air2 by ?is means ! z9c & lead rema9+ ) ! silv] are *ang$ into oxides & ! silv] rema9s beh9d unalt]$4 ,amalgamation process4 ,9 "s localities ! old amalgamation process is us$4 ,! silv] ore is treat$ ) common salt & f]r\s comp\nds1 :i* process conv]ts ! silv] fir/ into *loride & !n into metallic silv]4 ,m]cury is !n add$ & ?or\ghly mix$ ) ! mass1 =m+ an amalgam ) ! silv]4 ,aft] "s days ! e>?y mat]ials are wa%$ away & ! heavi] amalgam is recov]$4 ,! m]cury is di/ill$ (f & ! silv] left 9 impure =m4 ,ref9+ silv]4 ,! silv] obta9$ by ei!r ( ! above processes may /ill conta9 copp]1 gold1 & iron1 & is ref9$ by p>t+ ) sulphuric acid4 ,! metal is heat$ ) /rong sulphuric acid :i* dissolves ! silv]1 copp]1 & iron pres5t1 b n ! gold4 ,9 ! solution ( silv] sulphate s obta9$ copp] plates are susp5d$1 ^u :i* ! pure silv] precipitates1 ! copp] go+ into solution z sulphate1 z %[n 9 ! equation ,ag#b,,s#d ,cu #b;,ag ,cu,s,o#d4 ,! solution obta9$ z a by-product 9 ?is process furni%es mo/ ( ! blue vitriol ( comm]ce4 ,silv] is also ref9$ by electrolytic me?ods simil> to ^? us$ 9 ref9+ copp]4 ,prop]ties ( silv]4 ,silv] is a heavy1 r s(t1 :ite metal1 v ductile & malleable & capable ( tak+ a high poli%4 ,x surpasses all o!r metals z a conductor ( heat & electricity1 b is too co/ly to f9d ext5sive use = su* purposes4 ,x melts at a little l[] temp]ature ?an copp] 7#ifa74 ,x alloys readily ) o!r heavy metals1 & :5 x is to be us$ = co9age a small am\nt ( copp]--f #h to #aj--;is ne>ly always melt$ ) x to give x h>dness4 ,x is n act$ ^u by wat] or air1 b is quickly t>ni%$ :5 9 contact ) sulphur comp\nds1 turn+ q black 9 "t4 ,hydro*loric acid & fus$ alkalis d n act ^u x1 b nitric acid & hot1 conc5trat$ sulphuric acid dissolve x ) ease4 ,illu/ration3 ,fig4 #hh ,electroplat+4 ,s9ce silv] is n act$ ^u by wat] or air1 & has a pleas+ appe>ance1 x is us$ to coat v>i\s articles made ( *eap] metals4 ,su* articles are said to be silv] plat$4 ,! process by :i* ?is is done is call$ electroplat+4 ,x is c>ri$ on z foll[s3 ,! object to be plat$ 7su* z a spoon7 is atta*$ to a wire & dipp$ into a solution ( a silv] salt4 ,electrical connection is made 9 su* a way t ! article to be plat$ s]ves z ! ca?ode1 :ile ! anode is made up ( "o or m plates ( silv] 7,fig4 #hh1 ,a74 ,:5 a curr5t is pass$ ?r\gh ! electrolyte silv] dissolves f ! anode plate & deposits on ! ca?ode 9 ! =m ( a closely adh]+ lay]4 ,by mak+ ! prop] *ange 9 ! electrolyte & anode plate objects may be plat$ ) gold & o!r metals4 ,comp\nds ( silv]4 ,silv] =ms two oxides b only "o s]ies ( salts1 namely1 ! "o :i* corresponds to ! m]cur\s & cupr\s s]ies4 ,silv] nitrate 7lun> cau/ic7 7,ag,n,o#c74 ,?is salt is easily prep>$ by dissolv+ silv] 9 nitric acid & evaporat+ ! result+ solution4 ,x cry/allizes 9 flat plates1 & :5 heat$ c>efully c be melt$ )\t decomposition4 ,:5 ca/ into /icks x is call$ lun> cau/ic1 = x has a v corrosive action on fle%1 & is sometimes us$ 9 surg]y to burn away abnormal gr[?s4 ,! al*emi/s designat$ ! metals by ! names ( ! heav5ly bodies4 ,! moon 7luna7 0 ! symbol = silv]2 h5ce ! "n lun> cau/ic4 ,silv] sulphide 7,ag#b,s74 ,?is occurs 9 nature & con/itutes "o ( ! pr9cipal ores ( silv]4 ,x c be obta9$ 9 ! =m ( a black solid by pass+ hydrosulphuric acid ?r\gh a solution ( silv] nitrate4 ,comp\nds ( silv] ) ! halog5s4 ,! *loride1 bromide1 & iodide ( silv] are insoluble 9 wat] & acids1 & are !re=e precipitat$ by br++ toge!r a soluble halog5 salt ) silv] nitrate3 ,ag,n,o#c ,k,cl ,ag,cl ,,kno#c4 ,!y are rem>kable = ! fact t !y are v s5sitive to ! action ( light1 und]go+ a *ange ( color & *emical composition :5 expos$ to sunlight1 especially if 9 contact ) organic matt] su* z gelat94 ,photography4 ,! art ( photography is bas$ on ! fact t ! halog5 comp\nds ( silv] are affect$ by ! light1 p>ticul>ly 9 ! pres5ce ( organic matt]4 ,f a *emical /&po9t ! processes involv$ may be describ$ "u two heads3 7#a7 ! prep>ation ( ! negative2 7#b7 ! prep>ation ( ! pr9t4 #a4 ,prep>ation ( ! negative4 ,! plate us$ 9 ! prep>ation ( ! negative is made by spread+ a ?9 lay] ( gelat91 9 :i* silv] bromide is susp5d$ 7silv] iodide is sometimes add$ also71 ov] a glass plate or celluloid film & all[+ x to dry4 ,:5 ! plate s prep>$ is plac$ 9 a cam]a & ! image ( "s object is focus$ ^u x1 ! silv] salt und]goes a *ange :i* is proportional at ea* po9t to ! int5sity ( ! light fall+ ^u x4 ,9 ?is way an image ( ! object photograph$ is produc$ ^u ! plate1 :i* is1 h[ev]1 invisible & is !re=e call$ lat5t4 ,x c be made visible by ! process ( develop+4 ,to develop ! image ! expos$ plate is imm]s$ 9 a solution ( "s r$uc+ ag5t call$ ! develop]4 ,! develop] r$uces t portion ( ! silv] salt :i* has be5 affect$ by ! light1 deposit+ x 9 ! =m ( black metallic silv] :i* closely adh]es to ! plate4 ,! unaffect$ silv] salt1 ^u :i* ! develop] has no action1 mu/ n[ be remov$ f ! plate4 ,?is is done by imm]s+ ! plate 9 a solution ( sodium ?iosulphate 7hypo74 ,aft] ! silv] salt has be5 dissolv$ (f1 ! plate is wa%$ ) wat] & dri$4 ,! plate s prep>$ is call$ ! negative because x is a picture ( ! object photograph$1 ) ! lights exactly rev]s$4 ,?is is call$ fix+ ! negative4 #b4 ,prep>ation ( ! pr9t4 ,! pr9t is made f pap] :i* is prep>$ 9 ! same way z ! negative plate4 ,! negative is plac$ ^u ?is pap] & expos$ to ! light 9 su* a way t ! light mu/ pass ?r\gh ! negative be=e /rik+ ! pap]4 ,if ! pap] is coat$ ) silv] *loride1 a visible image is produc$1 9 :i* case a develop] is n ne$$4 ,! pro(s are made 9 ?is way4 ,9 ord] to make !m p]man5t ! un*ang$ silv] *loride mu/ be dissolv$ (f ) sodium ?iosulphate4 ,! pr9t is !n ton$ by dipp+ x into a solution ( gold or plat9um salts4 ,! silv] on ! pr9t passes into solution1 :ile ! gold or plat9um takes its place4 ,^! metals give a *>act]i/ic color or tone to ! pr9t1 ! gold mak+ x r$di% br[n1 :ile ! plat9um gives x a /eel-gray tone4 ,if a silv] bromide pap] is us$ 9 mak+ ! pr9t1 a lat5t image is produc$ :i* mu/ be develop$ z 9 ! case ( ! negative itself4 ,! silv] bromide is mu* m s5sitive ?an ! *loride1 s t ! pr9t+ c be done 9 artificial light4 ,s9ce ! d>ke/ places on ! negative cut (f ! mo/ light1 x is evid5t t ! lights ( ! pr9t w be ! rev]se ( ^? ( ! negative1 & w !re=e correspond to ^? ( ! object photograph$4 ,! pr9t is !re=e call$ ! positive4 ,,ex]cises #a4 ,acc\nt = ! fact t copp] has be5 us$ = s long a "t4 #b4 ,write equations = ! action ( conc5trat$ sulphuric & nitric acids ^u ! metals ( ?is family4 #c4 ,h[ w\ld y acc\nt = ! fact t normal copp] sulphate is slightly acid to litmus8 #d4 ,contra/ ! action ( heat on cupric nitrate & m]curic nitrate4 #e4 ,/ate reasons :y m]cury is adapt$ = use 9 !rmomet]s & b>omet]s4 #f4 ,h[ c\ld y di/+ui% betwe5 m]cur\s *loride & m]curic *loride8 #g4 ,write equations = ! prep>ation ( m]curic & m]cur\s iodides4 #h4 ,h[ w\ld y acc\nt = ! fact t solutions ( ! diff]5t salts ( a metal usually h ! same color8 #i4 ,crude silv] usually conta9s iron & lead4 ,:at w\ld become ( ^! metals 9 ref9+ by p>t+ ) sulphuric acid8 #aj4 ,9 ! amalgamation process = extract+ silv]1 h[ does f]r\s *loride conv]t silv] *loride into silv]8 ,write equation4 ,:y is ! silv] sulphide fir/ *ang$ into silv] *loride8 #aa4 ,:at impurities w\ld y expect to f9d 9 ! copp] sulphate prep>$ f ! ref9+ ( silv]8 #ab4 ,h[ c\ld y prep>e pure silv] *loride f a silv] co98 #ac4 ,m]curic nitrate & silv] nitrate are bo? :ite solids soluble 9 wat]4 ,h[ c\ld y di/+ui% betwe5 !m8 #ad4 ,acc\nt = ! fact t sulphur wat]s turn a silv] co9 black2 also = ! fact t a silv] spoon is black5$ by foods 7eggs1 = example7 conta9+ sulphur4 #ae4 ,:5 a solution ( silv] nitrate is add$ to a solution ( potassium *lorate no precipitate =ms4 ,h[ d y acc\nt = ! fact t a precipitate ( silv] *loride is n =m$8 ,,*apt] ,,xxix ,,t9 ,,& ,,lead ,,symbol ,,atomic ,,d5sity ,,melt+ ,,common ,,oxides ,,weight ,,po9t ,t9 ,sn #aai4j #g4ce #bce ,sn,o ,sn,o#b ,lead ,pb #bjf4i #aa4ch #cbg ,pb,o ,pb#c,o#d ,pb,o#b ,! family4 ,t9 & lead1 toge!r ) silicon & g]manium1 =m a family 9 ,gr\p ,,iv ( ! p]iodic table4 ,silicon has be5 discuss$ along ) ! non-metals1 :ile g]manium1 on acc\nt ( its r>ity1 ne$s only to be m5tion$4 ,! o!r family ( ,gr\p ,,iv includes c>bon1 already describ$1 & a numb] ( r>e elem5ts4 ,,t9 ,occurr5ce4 ,t9 is f\nd 9 nature *iefly z ! oxide 7,sn,o#b71 call$ cassit]ite or t9/one4 ,! mo/ fam\s m9es are ^? ( ,cornwall 9 ,engl&1 & ( ! ,malay ,p59sula & ,ea/ ,india ,isl&s2 9 small am\nts t9/one is f\nd 9 _m o!r localities4 ,metallurgy4 ,! metallurgy ( t9 is v simple4 ,! ore1 sep>at$ z f> z possible f e>?y mat]ials1 is mix$ ) c>bon & heat$ 9 a furnace1 ! r$uction tak+ place readily4 ,! equation is ,sn,o#b ,c ,sn ,,co#b4 ,! metal is (t5 purifi$ by c>efully heat+ x until x is p>tly melt$2 ! pure t9 melts fir/ & c be dra9$ away f ! impurities4 ,prop]ties4 ,pure t91 call$ block t91 is a s(t :ite metal ) a silv]-l appe>ance & lu/]2 x melts readily 7#bce7 & is some:at light] ?an copp]1 hav+ a d5sity ( #g4c4 ,x is q malleable & c be roll$ out into v ?9 %eets1 =m+ t9 foil2 mo/ t9 foil1 h[ev]1 conta9s a good deal ( lead4 ,"u ord9>y conditions x is q un*ang$ by air or moi/ure1 b at a high temp]ature x burns 9 air1 =m+ ! oxide ,sn,o#b4 ,dilute acids h no effect ^u x1 b conc5trat$ acids attack x readily4 ,conc5trat$ hydro*loric acid *anges x into ! *loride ,sn #b;,h,cl ,sn,cl#b #b;,h4 ,) sulphuric acid t9 sulphate & sulphur dioxide are =m$3 ,sn #b;,h#b,,s#d ,sn,s,o#d ,,s#b #b;,h#b,o ,conc5trat$ nitric acid oxidizes x1 =m+ a :ite insoluble comp\nd ( ! =mula ,h#b,sn,o#c1 call$ meta/annic acid3 #c,sn #d;,,hno#c ,h#b,o #c;,h#b,sn,o#c #d,,no4 ,uses ( t94 ,a great deal ( t9 is made into t9 plate by dipp+ ?9 /eel %eets into ! melt$ metal4 ,ow+ to ! way 9 :i* t9 resi/s ! action ( air & dilute acids1 t9 plate is us$ 9 _m ways1 su* z 9 ro(+1 & 9 ! manufacture ( t9 cans1 cook+ vessels1 & simil> articles4 ,_m useful alloys conta9 t91 "s ( :i* h be5 m5tion$ 9 connection ) copp]4 ,:5 t9 is alloy$ ) o!r metals ( l[ melt+ po9t1 s(t1 easily melt$ alloys are =m$ :i* are us$ = friction be>+s 9 ma*9]y2 t91 antimony1 lead1 & bismu? are ! *ief con/itu5ts ( ^! alloys4 ,pewt] & s(t sold] are alloys ( t9 & lead4 ,comp\nds ( t94 ,t9 =ms two s]ies ( comp\nds3 ! /ann\s1 9 :i* ! t9 is dival5t1 illu/rat$ 9 ! comp\nds ,sn,o1 ,sn,s1 ,sn,cl#b2 ! /annic1 9 :i* x is tetraval5t z %[n 9 ! comp\nds ,sn,o#b1 ,sn,s#b4 ,!re is also an acid1 ,h#b,sn,o#c1 call$ /annic acid1 :i* =ms a s]ies ( salts call$ /annates4 ,:ile ?is acid has ! same composition z meta/annic acid1 ! two are q diff]5t 9 _! *emical prop]ties4 ,?is diff]5ce is probably due to ! diff]5t arrangem5t ( ! atoms 9 ! molecules ( ! two sub/ances4 ,only a few comp\nds ( t9 ne$ be m5tion$4 ,/annic oxide 7,sn,o#b74 ,/annic oxide is ( int]e/1 s9ce x is ! *ief comp\nd ( t9 f\nd 9 nature4 ,x is sometimes f\nd 9 good-siz$ cry/als1 b z prep>$ 9 ! laboratory is a :ite p[d]4 ,:5 fus$ ) potassium hydroxide x =ms potassium /annate1 act+ v mu* l silicon dioxide3 ,sn,o#b #b,,koh ,k#b,sn,o#c ,h#b,o4 ,*lorides ( t94 ,/ann\s *loride is prep>$ by dissolv+ t9 9 conc5trat$ hydro*loric acid & evaporat+ ! solution to cry/allization4 ,! cry/als :i* are obta9$ h ! composition ,sn,cl#bb;,h#b,o1 & are kn[n z t9 cry/als4 ,by treat+ a solution ( /ann\s *loride ) aqua regia1 /annic *loride is =m$3 ,sn,cl#b #b;,cl ,sn,cl#d4 ,! salt :i* cry/allizes f su* a solution has ! composition ,sn,cl#de;,h#b,o1 & is kn[n comm]cially z oxymuriate ( t94 ,if metallic t9 is heat$ 9 a curr5t ( dry *lor9e1 ! anhydr\s *loride 7,sn,cl#d7 is obta9$ z a heavy colorless liquid :i* fumes /rongly on exposure to air4 ,! ease ) :i* /ann\s *loride takes up *lor9e to =m /annic *loride makes x a good r$uc+ ag5t 9 _m reactions1 *ang+ ! high] *lorides ( metals to l[] ones4 ,?us m]curic *loride is *ang$ into m]cur\s *loride3 ,sn,cl#b #b;,hg,cl#b ,sn,cl#d #b;,hg,cl4 ,if ! /ann\s *loride is 9 excess1 ! reaction may g fur!r1 produc+ metallic m]cury3 ,sn,cl#b #b;,hg,cl ,sn,cl#d #b;,hg4 ,f]ric *loride is 9 l mann] r$uc$ to f]r\s *loride3 ,sn,cl#c #b;,fe,cl#c ,sn,cl#d #b;,fe,cl#b4 ,! *lorides ( t91 z well z ! alkali /annates1 are mu* us$ z mordants 9 dye+ processes4 ,! hydroxides ( t9 & free /annic acid1 :i* are easily lib]at$ f ^! comp\nds1 possess 9 v m>k$ degree ! p[] ( fix+ dyes ^u fib]s1 z expla9$ "u alum9ium4 ,,lead ,occurr5ce4 ,lead is f\nd 9 nature *iefly z ! sulphide 7,pb,s71 call$ gal5a2 to a mu* small] ext5t x occurs z c>bonate1 sulphate1 *romate1 & 9 a few o!r =ms4 ,practically all ! lead ( comm]ce is made f gal5a1 two g5]al me?ods ( metallurgy be+ 9 use4 ,metallurgy4 #a4 ,! sulphide is melt$ ) scrap iron1 :5 iron sulphide & metallic lead are =m$2 ! liquid lead1 be+ ! heavi]1 s9ks to ! bottom ( ! vessel & c be drawn (f3 ,pb,s ,fe ,pb ,fe,s4 #b4 ,! sulphide is roa/$ 9 ! air until a "p ( x has be5 *ang$ into oxide & sulphate4 ,! air is !n %ut (f & ! heat+ cont9u$1 ! reactions indicat$ 9 ! foll[+ equations tak+ place3 #b,pb,o ,pb,s #c,pb ,,s#b1 ,pb,s,o#d ,pb,s #b,pb #b,,s#b4 ,! lead s prep>$ usually conta9s small am\nts ( silv]1 ars5ic1 antimony1 copp]1 & o!r metals4 ,! silv] is remov$ by ,p>kes's me?od1 z describ$ "u silv]1 & ! o!r metals 9 v>i\s ways4 ,! lead ( comm]ce is "o ( ! pure/ comm]cial metals1 conta9+ z a rule only a few t5?s p] c5t ( impurities4 ,prop]ties4 ,lead is a heavy metal 7d54 #aa4cc7 :i* has a brilliant silv]y lu/] on a fre%ly cut surface1 b :i* soon t>ni%es to a dull blue-gray color4 ,x is s(t1 easily fus$ 7melt+ at #cbg71 & q malleable1 b has little t\ghness or /r5g?4 ,x is n act$ ^u to any great ext5t by ! oxyg5 ( ! air "u ord9>y conditions1 b is *ang$ into oxide at a high temp]ature4 ,) ! exception ( hydro*loric & sulphuric acids1 mo/ acids1 ev5 v weak ones1 act ^u x1 =m+ soluble lead salts4 ,hot1 conc5trat$ hydro*loric & sulphuric acids also attack x to a slight ext5t4 ,uses4 ,lead is employ$ 9 ! manufacture ( lead pipes & 9 l>ge /orage batt]ies4 ,9 ! =m ( %eet lead x is us$ 9 l9+ ! *amb]s ( sulphuric acid works & 9 ! prep>ation ( pa9t pigm5ts4 ,"s alloys ( lead1 su* z sold] & pewt] 7lead & t971 %ot 7lead & ars5ic71 & s(t be>+ metals1 are widely us$4 ,type metal consi/s ( lead1 antimony1 & sometimes t94 ,comp\nds ( lead =m sev]al important pigm5ts4 ,comp\nds ( lead4 ,9 ne>ly all its comp\nds lead has a val5ce ( #b1 b a few correspond+ to /annic comp\nds h a val5ce ( #d4 ,lead oxides4 ,lead =ms a numb] ( oxides1 ! mo/ important ( :i* are li?>ge1 r$ lead or m9ium1 & lead p]oxide4 #a4 ,li?>ge 7,pb,o74 ,?is oxide =ms :5 lead is oxidiz$ at a r l[ temp]ature1 & is obta9$ z a by-product 9 silv] ref9+4 ,x is a pale yell[ p[d]1 & has a numb] ( comm]cial uses4 ,x is easily soluble 9 nitric acid3 ,pb,o #b;,,hno#c ,pb7,,no#c7b ,h#b,o4 #b4 ,r$ lead1 or m9ium 7,pb#c,o#d74 ,m9ium is prep>$ by heat+ lead 7or li?>ge7 to a high temp]ature 9 ! air4 ,x is a heavy p[d] ( a beautiful r$ color1 & is mu* us$ z a pigm5t4 #c4 ,lead p]oxide 7,pb,o#b74 ,?is is left z a residue :5 m9ium is heat$ ) nitric acid3 ,pb#c,o#d #d;,,hno#c #b,pb7,,no#c7b ,pb,o#b #b;,h#b,o4 ,x is a br[n p[d] :i* easily gives up a "p ( its oxyg5 &1 l manganese dioxide & b>ium dioxide1 is a good oxidiz+ ag5t4 ,soluble salts ( lead4 ,! soluble salts ( lead c be made by dissolv+ 7,pb7,c#b;,h#c,o#b7bc;,h#b,o71 li?>ge 9 acids4 ,lead acetate call$ sug> ( lead1 & lead nitrate 7,pb7,,no#c7b7 are ! mo/ famili> examples4 ,!y are :ile cry/all9e solids & are poison\s 9 "*4 ,insoluble salts ( lead2 lead c>bonate4 ,:ile ! normal c>bonate ( lead 7,pb,c,o#c7 is f\nd to "s ext5t1 9 nature & c be prep>$ 9 ! laboratory1 basic c>bonates ( v>y+ composition are mu* m easy to obta94 ,"o ( ! simple/ ( ^! has ! composition #b,pb,c,o#c,pb7,,oh7#b4 ,a mixture ( su* c>bonates is call$ :ite lead4 ,?is is prep>$ on a l>ge scale z a pa9t pigm5t & z a body = pa9ts :i* are to be color$ ) o!r sub/ances4 ,:ite lead4 ,:ite lead is an amorph\s :ite sub/ance :i*1 :5 mix$ ) oil1 has great cov]+ p[]1 t is1 x spreads out 9 an ev5 waxy film1 free f /reaks & lumps1 & cov]s ! entire surface ^u :i* x is spread4 ,its disadvantage z a pigm5t lies 9 ! fact t x gradually black5s :5 expos$ to sulphur comp\nds1 :i* are (t5 pres5t 9 ! air1 =m+ black lead sulphide 7,pb,s74 ,te*nical prep>ation ( :ite lead4 ,diff]5t me?ods are us$ 9 ! prep>ation ( :ite lead1 b ! old "o kn[n z ! ,dut* process is /ill ! pr9cipal "o employ$4 ,9 ?is process1 e>!nw>e pots ab\t t5 in*es high & ( ! %ape %[n 9 ,fig4 #hi are us$4 ,9 ! bottom ,a is plac$ a #c solution ( acetic acid 7v9eg> answ]s ! purpose v well74 ,! space above ?is is fill$ ) ?91 p]=at$1 circul> pieces ( lead1 support$ by ! flange ,b ( ! pot4 ,^! pots are plac$ close toge!r on a b$ ( tan b>k on ! floor ( a room kn[n z ! corrod+ room4 ,!y are cov]$ ov] ) bo>ds1 ^u :i* tan b>k is plac$1 & ano!r r[ ( pots is plac$ on ?is4 ,9 ?is way ! room is fill$4 ,! :ite lead is =m$ by ! fumes ( ! acetic acid1 toge!r ) ! c>bon dioxide set free 9 ! f]m5tation ( ! tan b>k act+ on ! lead4 ,ab\t ?ree mon?s are requir$ to complete ! process4 ,illu/ration #a3 ,fig4 #hi ,lead sulphide 7,pb,s74 ,9 nature ?is comp\nd occurs 9 highly cry/all9e condition1 ! cry/als hav+ mu* ! same lu/] z pure lead4 ,x is readily prep>$ 9 ! laboratory z a black precipitate1 by ! action ( hydrosulphuric acid ^u soluble lead salts3 ,pb7,,no#c7b ,h#b,s ,pb,s #b;,,hno#c4 ,x is insoluble bo? 9 wat] & 9 dilute acids4 ,o!r insoluble salts4 ,lead *romate 7,pb,cr,o#d7 is a yell[ sub/ance produc$ by ! action ( a soluble lead salt ^u a soluble *romate1 ?us3 ,k#b;,cr,o#d ,pb7,,no#c7b ,pb,cr,o#d #b ,,kno#c4 ,x is us$ z a yell[ pigm5t4 ,lead sulphate 7,pb,s,o#d7 is a :ite sub/ance sometimes f\nd 9 nature & easily prep>$ by precipitation4 ,lead *loride 7,pb,cl#b7 is likewise a :ite sub/ance ne>ly insoluble 9 cold wat]1 b readily soluble 9 boil+ wat]4 ,?orium & c]ium4 ,^! elem5ts are f\nd 9 a few r>e m9]als1 especially 9 ! monazite s& ( ! ,c>ol9as & ,brazil4 ,! oxides ( ^! elem5ts are us$ 9 ! prep>ation ( ! ,welsba* mantles = gas lights1 because ( ! int5se light giv5 out :5 a mixture ( ! oxides is heat$4 ,^! mantles conta9 ! oxides ( c]ium & ?orium 9 ! ratio ( ab\t #a ( ! =m] to #ii ( ! latt]4 ,comp\nds ( ?orium1 l ^? ( radium1 are f\nd to possess radio-activity1 b 9 a less degree4 ,,ex]cises #a4 ,h[ c\ld y detect lead if pres5t 9 t9 foil8 #b4 ,/ann\s *loride r$uces gold *loride 7,au,cl#c7 to gold4 ,give equation4 #c4 ,:at are ! products ( hydrolysis :5 /annic *loride is us$ z a mordant8 #d4 ,h[ c\ld y detect ars5ic1 antimony1 or copp] 9 lead8 #e4 ,:y is lead s ext5sively us$ = mak+ wat] pipes8 #f4 ,:at sulphates o!r ?an lead are insoluble8 #g4 ,c\ld lead nitrate be us$ 9 place ( b>ium *loride 9 te/+ = sulphates8 #h4 ,h[ mu* lead p]oxide c\ld be obta9$ f #a kg4 ( m9ium8 #i4 ,! purity ( :ite lead is usually det]m9$ by obs]v+ ! volume ( c>bon dioxide giv5 (f :5 x is treat$ ) an acid4 ,:at acid %\ld be us$8 ,on ! supposition t x has ! =mula #b,pb,c,o#c,pb7,,oh7#b1 h[ ne>ly pure 0 a sample if #a g4 gave #cj cc4 ( c>bon dioxide at #bj & #gej mm48 #aj4 ,silicon belongs 9 ! same family ) t9 & lead4 ,9 :at respects are ^! elem5ts simil>8 #aa4 ,:at weight ( t9 c\ld be obta9$ by ! r$uction ( #a ton ( cassit]ite8 #ab4 ,:at reaction w\ld y expect to take place :5 lead p]oxide is treat$ ) hydro*loric acid8 #ac4 ,:ite lead is (t5 adult]at$ ) b>ytes4 ,sugge/ a me?od = detect+ x1 if pres5t1 9 a giv5 example ( :ite lead4 ,,*apt] ,,xxx ,,manganese ,,& ,,*romium ,,symbol ,,atomic ,,d5sity ,,melt+ ,,=mulas ,,( ,,acids ,,weight ,,po9t ,manganese ,mn #ee4j #h4ja #aijj ,h#b,mn,o#d & ,h,mn,o#d ,*romium ,cr #eb4a #g4c #cjjj ,h#b;,cr,o#d & ,h#b;,cr#b,o#g ,g5]al4 ,manganese & *romium1 :ile belong+ to diff]5t families1 h s _m features 9 common 9 _! *emical conduct t !y may be /udi$ toge!r ) advantage4 ,!y diff] f mo/ ( ! elem5ts s f> /udi$ 9 t !y c act ei!r z acid-=m+ or base-=m+ elem5ts4 ,z base-=m+ elem5ts ea* ( ! metals =ms two s]ies ( salts4 ,9 ! "o s]ies1 designat$ by ! suffix ous1 ! metal is dival5t2 9 ! o!r s]ies1 designat$ by ! suffix ic1 ! metal is trival5t4 ,only ! mangan\s & ! *romic salts1 h[ev]1 are ( importance4 ,! acids 9 :i* ^! elem5ts play ! "p ( a non-metal are un/able1 b _! salts are usually /able1 & "s ( !m are important comp\nds4 ,,manganese ,occurr5ce4 ,manganese is f\nd 9 nature *iefly z ! dioxide ,mn,o#b1 call$ pyrolusite4 ,9 small] am\nts x occurs z ! oxides ,mn#b,o#c & ,mn#c,o#d1 & z ! c>bonate ,mn,c,o#c4 ,"s iron ores also conta9 manganese4 ,prep>ation & prop]ties4 ,! elem5t is difficult to prep>e 9 pure condition & has no comm]cial applications4 ,x c be prep>$1 h[ev]1 by r$uc+ ! oxide ) alum9ium p[d] or by ! use ( ! electric furnace1 ) c>bon z ! r$uc+ ag5t4 ,! metal some:at resembles iron 9 appe>ance1 b is h>d]1 less fusible1 & m readily act$ ^u by air & moi/ure4 ,acids readily dissolve x1 =m+ mangan\s salts4 ,oxides ( manganese4 ,! foll[+ oxides ( manganese are kn[n3 ,mn,o1 ,mn#b,o#c1 ,mn#c,o#d1 ,mn,o#b1 & ,mn#b,o#g4 ,only "o ( ^!1 ! dioxide1 ne$s special m5tion4 ,manganese dioxide 7pyrolusite7 7,mn,o#b74 ,?is sub/ance is ! mo/ abundant manganese comp\nd f\nd 9 nature1 & is ! ore f :i* all o!r comp\nds ( manganese are made4 ,x is a h>d1 brittle1 black sub/ance :i* is valuable z an oxidiz+ ag5t4 ,x w be recall$ t x is us$ 9 ! prep>ation ( *lor9e & oxyg51 9 decoloriz+ glass :i* conta9s iron1 & 9 ! manufacture ( f]romanganese4 ,comp\nds conta9+ manganese z a base-=m+ elem5t4 ,z has be5 /at$ previ\sly1 manganese =ms two s]ies ( salts4 ,! mo/ important ( ^! salts1 all ( :i* belong to ! mangan\s s]ies1 are ! foll[+3 ,mangan\s *loride ,mn,cl#bd;,h#b,o4 ,mangan\s sulphide ,mn,s4 ,mangan\s sulphate ,mn,s,o#dd;,h#b,o4 ,mangan\s c>bonate ,mn,c,o#c4 ,mangan\s hydroxide ,mn7,,oh7#b4 ,! *loride & sulphate may be prep>$ by heat+ ! dioxide ) hydro*loric & sulphuric acids respectively3 ,mn,o#b #d;,h,cl ,mn,cl#b #b;,h#b,o #b;,cl1 ,mn,o#b ,h#b,,s#d ,mn,s,o#d ,h#b,o ,o4 ,! sulphide1 c>bonate1 & hydroxide1 be+ insoluble1 may be prep>$ f a solution ( ! *loride or sulphate by precipitation ) ! appropriate reag5ts4 ,mo/ ( ! mangan\s salts are rose color$4 ,!y n only h =mulas simil> to ! f]r\s salts1 b resemble !m 9 _m ( _! *emical prop]ties4 ,comp\nds conta9+ manganese z an acid-=m+ elem5t4 ,manganese =ms two un/able acids1 namely1 manganic acid & p]manganic acid4 ,:ile ^! acids are ( little int]e/1 "s ( _! salts1 especially ! p]manganates1 are important comp\nds4 ,manganic acid & manganates4 ,:5 manganese dioxide is fus$ ) an alkali & an oxidiz+ ag5t a gre5 comp\nd is =m$4 ,! equation1 :5 cau/ic pota% is us$1 is z foll[s3 ,mn,o#b #b,,koh ,o ,k#b,mn,o#d ,h#b,o4 ,! gre5 comp\nd 7,k#b,mn,o#d7 is call$ potassium manganate1 & is a salt ( ! un/able manganic acid 7,h#b,mn,o#d74 ,! manganates are all v un/able4 ,p]manganic acid & ! p]manganates4 ,:5 c>bon dioxide is pass$ ?r\gh a solution ( a manganate a "p ( ! manganese is *ang$ into manganese dioxide1 :ile ! rema9d] =ms a salt ( ! un/able acid ,h,mn,o#d1 call$ p]manganic acid4 ,! equation is #c,k#b,mn,o#d #b;,,co#b ,mn,o#b #b,k,mn,o#d #b,k#b;,,co#c4 ,potassium p]manganate 7,k,mn,o#d7 cry/allizes 9 purple-black ne$les & is v soluble 9 wat]1 =m+ an int5sely purple solution4 ,all o!r p]manganates1 z well z p]manganic acid itself1 give solutions ( ! same color4 ,oxidiz+ prop]ties ( ! p]manganates4 ,! p]manganates are rem>kable = _! /rong oxidiz+ prop]ties4 ,:5 us$ z an oxidiz+ ag5t ! p]manganate is itself r$uc$1 ! exact "* ( ! products =m$ f x dep5d+ ^u :e!r ! oxidation takes place 7#a7 9 an alkal9e or neutral solution1 or 7#b7 9 an acid solution4 #a4 ,oxidation 9 alkal9e or neutral solution4 ,:5 ! solution is ei!r alkal9e or neutral ! potassium & ! manganese ( ! p]manganate are bo? conv]t$ into hydroxides1 z %[n 9 ! equation #b,k,mn,o#d #e;,h#b,o #b,mn7,,oh7#d #b,,koh #c,o4 #b4 ,oxidation 9 acid solution4 ,:5 free acid su* z sulphuric is pres5t1 ! potassium & ! manganese are bo? *ang$ into salts ( ! acid3 #b,k,mn,o#d #c;,h#b,,s#d ,k#b,,s#d #b,mn,s,o#d #c;,h#b,o #e,o4 ,"u ord9>y conditions1 h[ev]1 nei!r "o ( ^! reactions takes place except 9 ! pres5ce ( a ?ird sub/ance :i* is capable ( oxidation4 ,! oxyg5 is n giv5 (f 9 ! free /ate1 z ! equations %[1 b is us$ up 9 effect+ oxidation4 ,potassium p]manganate is p>ticul>ly valuable z an oxidiz+ ag5t n only because x acts readily ei!r 9 acid or 9 alkal9e solution1 b also because ! reaction takes place s easily t (t5 x is n ev5 necess>y to heat ! solution to secure action4 ,! sub/ance f9ds _m uses 9 ! laboratory1 especially 9 analytical "w4 ,x is also us$ z an antiseptic z well z a dis9fectant4 ,,*romium ,occurr5ce4 ,! ore f :i* all *romium comp\nds are made is *romite1 or *rome iron ore 7,fe,cr#b,o#d74 ,?is is f\nd mo/ abundantly 9 ,new ,cal$onia & ,turkey4 ,! elem5t also occurs 9 small quantities 9 _m o!r m9]als1 especially 9 crocoisite 7,pb,cr,o#d71 9 :i* m9]al x 0 fir/ discov]$4 ,prep>ation4 ,*romium1 l manganese1 is v h>d to r$uce f its ores1 ow+ to its great aff9ity = oxyg54 ,x c1 h[ev]1 be made by ! same me?ods :i* h prov$ successful ) manganese4 ,consid]able quantities ( an alloy ( *romium ) iron1 call$ f]ro*romium1 are n[ produc$ = ! /eel indu/ry4 ,prop]ties4 ,*romium is a v h>d metal ( ab\t ! same d5sity z iron4 ,x is "o ( ! mo/ infusible ( ! metals1 requir+ a temp]ature little %ort ( #cjjj = fusion4 ,at ord9>y temp]atures air has little action on x2 at high] temp]atures1 h[ev]1 x burns brilliantly4 ,nitric acid has no action on x1 b hydro*loric & dilute sulphuric acids dissolve x1 lib]at+ hydrog54 ,comp\nds conta9+ *romium z a base-=m+ elem5t4 ,:ile *romium =ms two s]ies ( salts1 *rom\s salts are difficult to prep>e & are ( little importance4 ,! mo/ important ( ! *romic s]ies are ! foll[+3 ,*romic hydroxide ,cr7,,oh7#c4 ,*romic *loride ,cr,cl#cf;,h#b,o4 ,*romic sulphate ,cr#b7,,s#d7c4 ,*rome alums ,*romic hydroxide 7,cr7,,oh7#c74 ,?is sub/ance1 be+ insoluble1 c be obta9$ by precipitat+ a solution ( ! *loride or sulphate ) a soluble hydroxide4 ,x is a gre5i% sub/ance :i*1 l alum9ium hydroxide1 dissolves 9 alkalis1 =m+ soluble salts4 ,dehydration ( *romium hydroxide4 ,:5 heat$ g5tly *romic hydroxide loses a "p ( its oxyg5 & hydrog51 =m+ ! sub/ance ,cr,o,,oh1 :i*1 l ! correspond+ alum9ium comp\nd1 has m pron\nc$ acid prop]ties ?an ! hydroxide4 ,x =ms a s]ies ( salts v simil> to ! sp9els2 *romite is ! f]r\s salt ( ?is acid1 hav+ ! =mula ,fe7,cr,o#b7b4 ,:5 heat$ to a high] temp]ature *romic hydroxide is completely dehydrat$1 =m+ ! trioxide ,cr#b,o#c4 ,?is resembles ! correspond+ oxides ( alum9ium & iron 9 _m respects4 ,x is a bright gre5 p[d]1 & :5 ignit$ /rongly becomes almo/ insoluble 9 acids1 z is also ! case ) alum9ium oxide4 ,*romic sulphate 7,cr#b7,,s#d7c74 ,?is comp\nd is a violet-color$ solid :i* dissolves 9 wat]1 =m+ a solution ( ! same color4 ,?is solution1 h[ev]1 turns gre5 on heat+1 ow+ to ! =mation ( basic salts4 ,*romic sulphate1 l f]ric & alum9ium sulphates1 unites ) ! sulphates ( ! alkali metals to =m alums1 ( :i* ! be/ kn[n are potassium *rome alum 7,k,cr7,,s#d7bab;,h#b,o7 & ammonium *rome alum 7,,nh#d;,cr7,,s#d7bab;,h#b,o74 ,^! =m beautiful d>k purple cry/als & h "s practical uses 9 ! tann+ indu/ry & 9 photography4 ,a numb] ( ! salts ( *romium are also us$ 9 ! dye+ indu/ry1 = !y hydrolyze l alum9ium salts & ! hydroxide =ms a good mordant4 ,hydrolysis ( *romium salts4 ,:5 ammonium sulphide is add$ to a solution ( a *romium salt1 su* z ! sulphate1 *romium hydroxide precipitates in/ead ( ! sulphide4 ,?is is due to ! fact t *romic sulphide1 l alum9ium sulphide1 hydrolyzes 9 ! pres5ce ( wat]1 =m+ *romic hydroxide & hydrosulphuric acid4 ,simil>ly1 a soluble c>bonate precipitates a basic c>bonate ( *romium4 ,comp\nds conta9+ *romium z an acid-=m+ elem5t4 ,l manganese1 *romium =ms two un/able acids1 namely1 *romic acid & di*romic acid4 ,_! salts1 ! *romates & di*romates1 are important comp\nds4 ,*romates4 ,:5 a *romium comp\nd is fus$ ) an alkali & an oxidiz+ ag5t a *romate is produc$4 ,:5 potassium hydroxide is us$ z ! alkali ! equation is #b;,cr7,,oh7#c #d,,koh #c,o #b,k#b;,cr,o#d #e;,h#b,o4 ,?is reaction recalls ! =mation ( a manganate "u simil> conditions4 ,prop]ties ( *romates4 ,! *romates are salts ( ! un/able *romic acid 7,h#b;,cr,o#d71 & z a rule are yell[ 9 color4 ,lead *romate 7,pb,cr,o#d7 is ! well-kn[n pigm5t *rome yell[4 ,mo/ ( ! *romates are insoluble & c !re=e be prep>$ by precipitation4 ,?us1 :5 a solution ( potassium *romate is add$ to solutions ( lead nitrate & b>ium nitrate respectively1 ! reactions express$ by ! foll[+ equations occur3 ,pb7,,no#c7b ,k#b;,cr,o#d ,pb,cr,o#d #b,,kno#c1 ,ba7,,no#c7b ,k#b;,cr,o#d ,ba,cr,o#d #b,,kno#c4 ,! *romates ( lead & b>ium sep>ate z yell[ precipitates4 ,! pres5ce ( ei!r ( ^! two metals c be detect$ by tak+ advantage ( ^! reactions4 ,di*romates4 ,:5 potassium *romate is treat$ ) an acid ! potassium salt ( ! un/able di*romic acid 7,h#b;,cr#b,o#g7 is =m$3 #b,k#b;,cr,o#d ,h#b,,s#d ,k#b;,cr#b,o#g ,k#b,,s#d ,h#b,o4 ,! relation betwe5 ! *romates & di*romates is ! same z t betwe5 ! phosphates & ! pyrophosphates4 ,potassium di*romate might !re=e be call$ potassium pyro*romate4 ,potassium di*romate 7,k#b;,cr#b,o#g74 ,?is is ! be/ kn[n di*romate1 & is ! mo/ famili> *romium comp\nd4 ,x =ms l>ge cry/als ( a brilliant r$ color1 & is r sp>+ly soluble 9 wat]4 ,:5 treat$ ) potassium hydroxide x is conv]t$ into ! *romate ,k#b;,cr#b,o#g #b,,koh #b,k#b;,cr,o#d ,h#b,o4 ,:5 add$ to a solution ( lead or b>ium salt ! correspond+ *romates 7n di*romates7 are precipitat$4 ,) b>ium nitrate ! equation is #b;,ba7,,no#c7b ,k#b;,cr#b,o#g ,h#b,o #b;,ba,cr,o#d #b,,kno#c #b;,,hno#c4 ,potassium di*romate f9ds use 9 _m indu/ries z an oxidiz+ ag5t1 especially 9 ! prep>ation ( organic sub/ances1 su* z ! dye aliz>91 & 9 ! con/ruction ( sev]al v>ieties ( electric batt]ies4 ,sodium *romates4 ,! reason :y ! potassium salt r ?an ! sodium comp\nd is us$ is t sodium *romate & di*romate are s soluble t x is h>d to prep>e !m pure4 ,?is difficulty is be+ ov]come n[1 & ! sodium comp\nds are replac+ ! correspond+ potassium salts4 ,?is is ( advantage1 s9ce a sodium salt is *eap] ?an a potassium salt1 s f> z raw mat]ials g4 ,oxidiz+ action ( *romates & di*romates4 ,:5 a dilute solution ( a *romate or di*romate is acidifi$ ) an acid1 su* z sulphuric acid1 no reaction app>5tly takes place4 ,h[ev]1 if !re is pres5t a ?ird sub/ance capable ( oxidation1 ! *romium comp\nd gives up a portion ( its oxyg5 to ?is sub/ance4 ,s9ce ! *romate *anges into a di*romate 9 ! pres5ce ( an acid1 x w be suffici5t to /udy ! action ( ! di*romates alone4 ,! reaction takes place 9 two /eps4 ,?us1 :5 a solution ( f]r\s sulphate is add$ to a solution ( potassium di*romate acidifi$ ) sulphuric acid1 ! reaction is express$ by ! foll[+ equations3 7#a7 ,k#b;,cr#b,o#g #d;,h#b,,s#d ,k#b,,s#d ,cr#b7,,s#d7c #d;,h#b,o #c,o1 7#b7 #f;,fe,s,o#d #c;,h#b,,s#d #c,o #c;,fe#b7,,s#d7c #c;,h#b,o4 ,! di*romate decomposes 9 v mu* ! same way z a p]manganate does1 ! potassium & *romium be+ bo? *ang$ into salts 9 :i* !y play ! "p ( metals1 :ile "p ( ! oxyg5 ( ! di*romate is lib]at$4 ,by comb9+ equations 7#a7 & 7#b71 ! foll[+ is obta9$3 ,k#b;,cr#b,o#g #g;,h#b,,s#d #f;,fe,s,o#d ,k#b,,s#d ,cr#b7,,s#d7c #c;,fe#b7,,s#d7c #g;,h#bj4 ,?is reaction is (t5 employ$ 9 ! e/imation ( iron 9 iron ores4 ,potassium *rome alum4 ,x w be notic$ t ! oxidiz+ action ( potassium di*romate leaves potassium sulphate & *romium sulphate z ! products ( ! reaction4 ,on evaporat+ ! solution ^! sub/ances cry/allize out z potassium *rome alum1 :i* sub/ance is produc$ z a by-product 9 ! indu/ries us+ potassium di*romate = oxidiz+ purposes4 ,*romic anhydride 7,cr,o#c74 ,:5 conc5trat$ sulphuric acid is add$ to a /rong solution ( potassium di*romate1 & ! liquid all[$ to /&1 deep r$ ne$le-%ap$ cry/als appe> :i* h ! =mula ,cr,o#c4,?is oxide ( *romium is call$ *romic anhydride1 s9ce x comb9es readily ) wat] to =m *romic acid3 ,cr,o#c ,h#b,o ,h#b;,cr,o#d4 ,x is !re=e analog\s to sulphur trioxide :i* =ms sulphuric acid 9 a simil> way3 ,,s#c ,h#b,o ,h#b,,s#d4 ,*romic anhydride is a v /rong oxidiz+ ag5t1 giv+ up oxyg5 & =m+ *romic oxide3 #b;,cr,o#c ,cr#b,o#c #c,o4 ,r>e elem5ts ( ! family4 ,molybd5um1 tung/51 & uranium are ?ree r r>e elem5ts belong+ 9 ! same family ) *romium1 & =m _m comp\nds :i* are simil> 9 =mulas to ! correspond+ comp\nds ( *romium4 ,!y c play ! "p ( metals & also =m acids resembl+ *romic acid 9 =mula4 ,?us we h molybdic acid 7,h#b,mo,o#d71 ! ammonium salt ( :i* is 7,,nh#d7b,mo,o#d4 ,?is salt has ! prop]ty ( comb9+ ) phosphoric acid to =m a v complex sub/ance :i* is insoluble 9 nitric acid4 ,on ?is acc\nt molybdic acid is (t5 us$ 9 ! e/imation ( ! phosphoric acid pres5t 9 a sub/ance4 ,l *romium1 ! metals are difficult to prep>e 9 pure condition4 ,alloys ) iron c be prep>$ by r$uc+ ! mix$ oxides ) c>bon 9 an electric furnace2 ^! alloys are us$ to "s ext5t 9 prep>+ special k9ds ( /eel4 ,,ex]cises #a4 ,h[ does pyrolusite effect ! decoloriz+ ( glass conta9+ iron8 #b4 ,write ! equations = ! prep>ation ( mangan\s *loride1 c>bonate1 & hydroxide4 #c4 ,write ! equations repres5t+ ! reactions :i* take place :5 f]r\s sulphate is oxidiz$ to f]ric sulphate by potassium p]manganate 9 ! pres5ce ( sulphuric acid4 #d4 ,9 ! pres5ce ( sulphuric acid1 oxalic acid is oxidiz$ by potassium p]manganate accord+ to ! equation ,c#b;,h#b,o#d ,o #b;,,co#b ,h#b,o4 ,write ! complete equation4 #e4 #aj g4 ( iron 7 dissolv$ 9 sulphuric acid & oxidiz$ to f]ric sulphate by potassium p]manganate4 ,:at weight ( ! p]manganate 0 requir$8 #f4 ,:at weight ( f]ro*romium conta9+ #dj *romium mu/ be add$ to a ton ( /eel to produce an alloy conta9+ #a ( *romium8 #g4 ,write ! equation repres5t+ ! action ( ammonium sulphide ^u *romium sulphate4 #h4 ,potassium *romate oxidizes hydro*loric acid1 =m+ *lor9e4 ,write ! complete equation4 #i4 ,give ! action ( sulphuric acid on potassium di*romate 7a7 9 ! pres5ce ( a l>ge am\nt ( wat]2 7b7 9 ! pres5ce ( a small am\nt ( wat]4 ,,*apt] ,,xxxi ,,gold ,,& ,,! ,,plat9um ,,family ,,atomic ,,highe/ ,,highe/ ,,melt+ ,,symbol ,,weight ,,d5sity ,,oxide ,,*loride ,,po9t ,ru!nium ,ru #aja4g #ab4bf ,ru,o#d ,ru,cl#d ,electric arc ,rhodium ,rh #ajc4 #ab4a ,rh,o#b ,rh,cl#b ,electric arc ,palladium ,pd #ajf4e #aa4h ,pd,o#b ,pd,cl#d #aejj ,iridium ,ir #aic4 #bb4db ,ir,o#b ,ir,cl#d #aiej ,osmium ,os #aia4 #bb4dg ,os,o#d ,os,cl#d ,electric arc ,plat9um ,pt #aid4h #ba4ej ,pt,o#b ,pt,cl#d #aggi ,gold ,au #aig4b #ai4cj ,au#b,o#c ,au,cl#c #ajfd ,! family4 ,foll[+ iron1 nickel1 & cobalt 9 ! eigh? column ( ! p]iodic table are two gr\ps ( ?ree elem5ts ea*4 ,! metals ( ! fir/ ( ^! gr\ps--ru!nium1 rhodium1 & palladium--h atomic weights ne> #ajj & d5sities ne> #ab4 ,! metals ( ! o!r gr\p--iridium1 osmium1 & plat9um--h atomic weights ne> #bjj & d5sities ne> #ba4 ,^! six r>e elem5ts h v simil> physical prop]ties & resemble ea* o!r *emically n only 9 ! type ( comp\nds :i* !y =m b also 9 ! great v>iety ( !m4 ,!y occur closely associat$ 9 nature1 usually z alloys ( plat9um 9 ! =m ( irregul> metallic gra9s 9 s& & gravel4 ,plat9um is by f> ! mo/ abundant ( ! six4 ,al?\gh ! p]iodic classification assigns gold to ! silv]-copp] gr\p1 its physical z well z _m ( its *emical prop]ties mu* m closely resemble ^? ( ! plat9um metals1 & x c he conv5i5tly consid]$ along ) !m4 ,! f\r elem5ts gold1 plat9um1 osmium1 & iridium are ! heavie/ sub/ances kn[n1 be+ ab\t twice z heavy z lead4 ,,plat9um ,occurr5ce4 ,ab\t #ij ( ! plat9um ( comm]ce comes f ,russia1 small am\nts be+ produc$ 9 ,cali=nia1 ,brazil1 & ,au/ralia4 ,prep>ation4 ,native plat9um is usually alloy$ ) gold & ! plat9um metals4 ,to sep>ate ! plat9um ! alloy is dissolv$ 9 aqua regia1 :i* conv]ts ! plat9um into *loroplat9ic acid 7,h#b,pt,cl#f74 ,ammonium *loride is !n add$1 :i* precipitates ! plat9um z insoluble ammonium *loroplat9ate3 ,h#b,pt,cl#f #b,,nh#d;,cl 7,,nh#d7b,pt,cl#f #b;,h,cl4 ,"s iridium is also precipitat$ z a simil> comp\nd4 ,on ignition ! d\ble *loride is decompos$1 leav+ ! plat9um z a spongy metallic mass1 :i* is melt$ 9 an electric furnace & roll$ or hamm]$ into ! desir$ %ape4 ,physical prop]ties4 ,plat9um is a grayi%-:ite metal ( high lu/]1 & is v malleable & ductile4 ,x melts 9 ! oxyhydrog5 bl[pipe & 9 ! electric furnace2 x is h>d] ?an gold & is a good conductor ( electricity4 ,9 f9ely divid$ =m x has ! ability to absorb or occlude gases1 especially oxyg5 & hydrog54 ,^! gases1 :5 occlud$1 are 9 a v active condition resembl+ ! nasc5t /ate1 & c comb9e ) ea* o!r at ord9>y temp]atures4 ,a jet ( hydrog5 or coal gas direct$ ^u spongy plat9um is at once ignit$4 ,plat9um z a catalytic ag5t4 ,plat9um is rem>kable = its prop]ty ( act+ z a catalytic ag5t 9 a l>ge numb] ( *emical reactions1 & m5tion has be5 made ( ?is use ( ! metal 9 connection ) ! manufacture ( sulphuric acid4 ,:5 desir$ = ?is purpose "s por\s or fibr\s sub/ance1 su* z asbe/os1 is soak$ 9 a solution ( plat9ic *loride & !n ignit$4 ,! plat9um comp\nd is decompos$ & ! plat9um deposit$ 9 v f9ely divid$ =m4 ,asbe/os prep>$ 9 ?is way is call$ plat9iz$ asbe/os4 ,! catalytic action seems to be 9 "p connect$ ) ! prop]ty ( absorb+ gases & r5d]+ !m nasc5t4 ,"s o!r metals possess ?is same p[]1 notably palladium1 :i* is rem>kable = its ability to absorb hydrog54 ,*emical prop]ties4 ,plat9um is a v inactive elem5t *emically1 & is n attack$ by any ( ! common acids4 ,aqua regia sl[ly dissolves x1 =m+ plat9ic *loride 7,pt,cl#d71 :i* 9 turn unites ) ! hydro*loric acid pres5t 9 ! aqua regia1 =m+ ! comp\nd *loroplat9ic acid 7,h#b,pt,cl#f74 ,plat9um is attack$ by fus$ alkalis4 ,x comb9es at high] temp]atures ) c>bon & phosphorus & alloys ) _m metals4 ,x is readily attack$ by *lor9e b n by oxidiz+ ag5ts4 ,applications4 ,plat9um is v valuable z a mat]ial = ! manufacture ( *emical ut5sils :i* are requir$ to /& a high temp]ature or ! action ( /rong reag5ts4 ,plat9um crucibles1 di%es1 =ceps1 electrodes1 & simil> articles are indisp5sable 9 ! *emical laboratory4 ,9 ! indu/ries x is us$ = su* purposes z ! manufacture ( pans = evaporat+ sulphuric acid1 wires = seal+ ?r\gh inc&esc5t light bulbs1 & = mak+ a great v>iety ( in/rum5ts4 ,un=tunately ! supply ( ! metal is v limit$1 & ! co/ is /eadily advanc+1 s t x is n[ m valuable ?an gold4 ,comp\nds4 ,plat9um =ms two s]ies ( salts ( :i* plat9\s *loride 7,pt,cl#b7 & plat9ic *loride 7,pt,cl#d7 are examples4 ,plat9ates are also kn[n4 ,:ile a great v>iety ( comp\nds ( plat9um h be5 made1 ! sub/ance is *iefly employ$ 9 ! metallic /ate4 ,plat9ic *loride 7,pt,cl#d74 ,plat9ic *loride is an orange-color$1 soluble comp\nd made by heat+ *loroplat9ic acid 9 a curr5t ( *lor9e4 ,if hydro*loric acid is add$ to a solution ( ! sub/ance1 ! two comb9e1 =m+ *loroplat9ic acid 7,h#b,pt,cl#f73 #b;,h,cl ,pt,cl#d ,h#b,pt,cl#f4 ,! potassium & ammonium salts ( ?is acid are ne>ly insoluble 9 wat] & alcohol4 ,! acid is !re=e us$ z a reag5t to precipitate potassium 9 analytical "w4 ,) potassium *loride ! equation is #b,k,cl ,h#b,pt,cl#f ,k#b,pt,cl#f #b;,h,cl4 ,o!r metals ( ! family4 ,! o!r memb]s ( ! family h few applications4 ,iridium is us$ 9 ! =m ( a plat9um alloy1 s9ce ! alloy is mu* h>d] ?an pure plat9um & is ev5 less fusible4 ,?is alloy is sometimes us$ to po9t gold p5s4 ,osmium tetroxide 7,os,o#d7 is a v volatile liquid & is us$ "u ! "n ( osmic acid z a /a9 = sections 9 microscopy4 ,,gold ,occurr5ce4 ,gold has be5 f\nd 9 _m localities1 ! mo/ fam\s be+ ,s\? ,africa1 ,au/ralia1 ,russia1 & ! ,unit$ ,/ates4 ,9 ?is c\ntry x is f\nd 9 ,alaska & 9 ne>ly half ( ! /ates ( ! union1 notably 9 ,cali=nia1 ,colorado1 & ,nevada4 ,x is usually f\nd 9 ! native condition1 frequ5tly alloy$ ) silv]2 9 comb9ation x is sometimes f\nd z telluride 7,au,te#b71 & 9 a few o!r comp\nds4 ,m9+4 ,native gold occurs 9 ! =m ( small gra9s or l>g] nuggets 9 ! s&s ( old riv]s1 or imb$d$ 9 qu>tz ve9s 9 rocks4 ,9 ! fir/ case x is obta9$ 9 crude =m by plac] m9+4 ,! s& conta9+ ! gold is %ak5 or /irr$ 9 tr\ghs ( runn+ wat]s call$ sluices4 ,?is sweeps away ! s& b all[s ! heavi] gold to s9k to ! bottom ( ! sluice4 ,sometimes ! s& conta9+ ! gold is wa%$ away f its natural location into ! sluices by p[]ful /reams ( wat] deliv]$ "u pressure f pipes4 ,?is is call$ hydraulic m9+4 ,9 ve9 m9+ ! gold-be>+ qu>tz is m9$ f ! ve9s1 /amp$ into f9e p[d] 9 /amp+ mills1 & ! gold extract$ by "o ( ! processes to be describ$4 ,extraction4 #a4 ,amalgamation process4 ,9 ! amalgamation process ! p[d] conta9+ ! gold is wa%$ ov] a s]ies ( copp] plates ^: surfaces h be5 amalgamat$ ) m]cury4 ,! gold /icks to ! m]cury or alloys ) x1 & aft] a "t ! gold & m]cury are scrap$ (f & ! mixture is di/ill$4 ,! m]cury di/ills (f & ! gold is left 9 ! retort ready = ref9+4 #b4 ,*lor9ation process4 ,:5 gold occurs along ) metallic sulphides x is (t5 extract$ by *lor9ation4 ,! ore is fir/ roa/$1 & is !n moi/5$ & treat$ ) *lor9e4 ,?is dissolves ! gold b n ! metallic oxides3 ,au #c;,cl ,au,cl#c4 ,! gold *loride1 be+ soluble1 is extract$ f ! mixture ) wat]1 & ! gold is precipitat$ f ! solution1 usually by add+ f]r\s sulphate3 ,au,cl#c #c;,fe,s,o#d ,au ,fe,cl#c ,fe#b7,,s#d7c4 #c4 ,cyanide process4 ,?is process dep5ds ^u ! fact t gold is soluble 9 a solution ( potassium cyanide 9 ! pres5ce ( ! oxyg5 ( ! air4 ,! p[d] f ! /amp+ mills is treat$ ) a v dilute potassium cyanide solution :i* extracts ! gold3 #b;,au #d,,kcn ,h#b,o ,o #b,,koh #b,k,au7,,cn7#b4 ,f ?is solution ! gold c be obta9$ by electrolysis or by precipitation ) metallic z9c3 #b,k,au7,,cn7#b ,zn ,k#b,zn7,,cn7#d #b;,au4 ,ref9+ ( gold4 ,gold is ref9$ by ?ree g5]al me?ods3 #a4 ,electrolysis4 ,:5 gold is dissolv$ 9 a solution ( potassium cyanide1 & ! solution electrolyz$1 ! gold is deposit$ 9 v pure condition on ! ca?ode4 #b4 ,cupellation4 ,:5 ! gold is alloy$ ) easily oxidizable metals1 su* z copp] or lead1 x may be ref9$ by cupellation4 ,! alloy is fus$ ) an oxidiz+ flame on a %all[ he>? made ( bone a%1 :i* sub/ance has ! prop]ty ( absorb+ metallic oxides b n ! gold4 ,any silv] :i* may be pres5t rema9s alloy$ ) ! gold4 #c4 ,p>t+ ) sulphuric acid4 ,gold may be sep>at$ f silv]1 z well z f _m o!r metals1 by heat+ ! alloy ) conc5trat$ sulphuric acid4 ,?is dissolves ! silv]1 :ile ! gold is n attack$4 ,physical prop]ties4 ,gold is a v heavy bright yell[ metal1 exce$+ly malleable & ductile1 & a good conductor ( electricity4 ,x is q s(t & is usually alloy$ ) copp] or silv] to give x ! h>dness requir$ = mo/ practical uses4 ,! degree ( f95ess is express$ 9 t]ms ( c>ats1 pure gold be+ tw5ty-f\r c>ats2 ! gold us$ = jewelry is usually eighte5 c>ats1 eighte5 p>ts be+ gold & six p>ts copp] or silv]4 ,gold co9age is #ij gold & #aj copp]4 ,*emical prop]ties4 ,gold is n attack$ by any "o ( ! common acids2 aqua regia easily dissolves x1 =m+ gold *loride 7,au,cl#c71 :i* 9 turn comb9es ) hydro*loric acid to =m *lorauric acid 7,h,au,cl#d74 ,fus$ alkalis also attack x4 ,mo/ oxidiz+ ag5ts are )\t action ^u x1 & 9 g5]al x is n an active elem5t4 ,comp\nds4 ,! comp\nds ( gold1 ?\gh num]\s & v>i$ 9 "*1 are ( comp>atively little importance & ne$ n be describ$ 9 detail4 ,! elem5t =ms two s]ies ( salts 9 :i* x acts z a metal3 9 ! aur\s s]ies ! gold is unival5t1 ! *loride hav+ ! =mula ,au,cl2 9 ! auric s]ies x is trival5t1 auric *loride hav+ ! =mula ,au,cl#c4 ,gold also acts z an acid-=m+ elem5t1 =m+ su* comp\nds z potassium aurate 7,k,au,o#b74 ,its comp\nds are v easily decompos$1 h[ev]1 metallic gold sep>at+ f !m4 ,,ex]cises #a4 ,f ! me?od ( prep>ation ( plat9um1 :at metal is likely to be alloy$ ) x8 #b4 ,! plat9um *loride ( ! laboratory is made by dissolv+ plat9um 9 aqua regia4 ,:at is ! comp\nd8 #c4 ,h[ w\ld y expect potassium aurate & plat9ate to be =m$8 ,:at precautions w\ld ?is sugge/ 9 ! use ( plat9um vessels8 #d4 ,:y mu/ gold ores be roa/$ 9 ! *lor9ation process8 ,,*apt] ,,xxxii ,,"s ,,simple ,,organic ,,comp\nds ,division ( *emi/ry into organic & inorganic4 ,*emi/ry is usually divid$ into two great divisions1--organic & inorganic4 ,! orig9al significance ( ^! t]ms 0 entirely diff]5t f ! mean+ :i* !y h at ! pres5t "t4 #a4 ,orig9al significance4 ,! division into organic & inorganic 0 orig9ally made because x 0 believ$ t ^? sub/ances :i* con/itute ! ess5tial p>ts ( liv+ organisms 7 built up "u ! influ5ce ( ! life =ce ( ! organism4 ,su* sub/ances1 !re=e1 %\ld be reg>d$ z diff]5t f ^? comp\nds prep>$ 9 ! laboratory or =m$ f ! inorganic or m9]al con/itu5ts ( ! e>?4 ,9 accordance ) ?is view organic *emi/ry includ$ ^? sub/ances =m$ by liv+ organisms4 ,inorganic *emi/ry1 on ! o!r h&1 includ$ all sub/ances =m$ f ! m9]al portions ( ! e>?4 ,9 #ahbh ! ,g]man *emi/ ,whl] prep>$ urea1 a typical organic comp\nd1 f inorganic mat]ials4 ,! syn!sis ( o!r s-call$ organic comp\nds foll[$1 & at pres5t x is kn[n t ! same *emical laws apply to all sub/ances :e!r =m$ 9 ! liv+ organism or prep>$ 9 ! laboratory f inorganic con/itu5ts4 ,! t]ms organic & inorganic h !re=e lo/ _! orig9al significance4 #b4 ,pres5t significance4 ,! great majority ( ! comp\nds f\nd 9 liv+ organisms conta9 c>bon1 & ! t]m organic *emi/ry1 z us$ at pres5t1 includes n only ^! comp\nds b all comp\nds ( c>bon4 ,organic *emi/ry has become1 !re=e1 ! *emi/ry ( ! comp\nds ( c>bon1 all o!r sub/ances be+ treat$ "u ! head ( inorganic *emi/ry4 ,?is sep>ation ( ! comp\nds ( c>bon into a gr\p by !mselves is made almo/ necess>y by _! great numb]1 ov] "o hundr$ ?\s& hav+ be5 record$4 ,= conv5i5ce "s ( ! simpl] c>bon comp\nds1 su* z ! oxides & ! c>bonates1 are usually discuss$ 9 inorganic *emi/ry4 ,! gr\p+ ( comp\nds 9 classes4 ,! /udy ( organic *emi/ry is mu* simplifi$ by ! fact t ! l>ge numb] ( bodies includ$ 9 ?is field may be gr\p$ 9 classes ( simil> comp\nds4 ,x ?us becomes possible to /udy ! prop]ties ( ea* class z a :ole1 9 mu* ! same way z we /udy a gr\p ( elem5ts4 ,! mo/ important ( ^! classes are ! hydroc>bons1 ! alcohols1 ! aldehydes1 ! acids1 ! e!real salts1 ! e!rs1 ! ketones1 ! organic bases1 & ! c>bohydrates4 ,a few memb]s ( ea* ( ^! classes w n[ be discuss$ briefly4 ,,! ,,hydroc>bons ,c>bon & hydrog5 comb9e to =m a l>ge numb] ( comp\nds4 ,^! comp\nds are kn[n collectively z ! hydroc>bons4 ,!y may be divid$ into a numb] ( gr\ps or s]ies1 ea* be+ nam$ f its fir/ memb]4 ,"s ( ! gr\ps are z foll[s3 ,,me?ane ,,s]ies ,,*#d me?ane ,c#b;,h#f e?ane ,c#c;,h#h propane ,c#d;,h#aj butane ,c#e;,h#ab p5tane ,c#f;,h#ad hexane ,c#g;,h#af heptane ,c#h;,h#ah octane ,,e?yl5e ,,s]ies ,c#b;,h#d e?yl5e ,c#c;,h#f propyl5e ,c#d;,h#h butyl5e ,,b5z5e ,,s]ies ,c#f;,h#f b5z5e ,c#g;,h#h tolu5e ,c#h;,h#aj xyl5e ,,acetyl5e ,,s]ies ,c#b;,h#b acetyl5e ,c#c;,h#d allyl5e ,only ! l[] memb]s 7t is1 ^? :i* conta9 a small numb] ( c>bon atoms7 ( ! above gr\ps are giv54 ,! me?ane s]ies is ! mo/ ext5sive1 all ( ! comp\nds up to ,c#bd;,h#ej be+ kn[n4 ,x w be notic$ t ! successive memb]s ( ea* ( ! above s]ies diff] by ! gr\p ( atoms 7,,*#b74 ,su* a s]ies is call$ an homolog\s s]ies4 ,9 g5]al1 x may be /at$ t ! memb]s ( an homolog\s s]ies %[ a regul> gradation 9 mo/ physical prop]ties & are simil> 9 *emical prop]ties4 ,?us 9 ! me?ane gr\p ! fir/ f\r memb]s are gases at ord9>y temp]atures2 ^? conta9+ f five to sixte5 c>bon atoms are liquids1 ! boil+ po9ts ( :i* increase ) ! numb] ( c>bon atoms pres5t4 ,^? conta9+ m ?an sixte5 c>bon atoms are solids4 ,s\rces ( ! hydroc>bons4 ,!re are two *ief s\rces ( ! hydroc>bons1 namely1 7#a7 crude petroleum & 7#b7 coal t>4 #a4 ,crude petroleum4 ,?is is a liquid pump$ f wells driv5 into ! e>? 9 c]ta9 localities4 ,p5nsylvania1 ,ohio1 ,kansas1 ,cali=nia1 & ,texas are ! *ief oil-produc+ regions 9 ! ,unit$ ,/ates4 ,! crude petroleum consi/s l>gely ( liquid hydroc>bons 9 :i* are dissolv$ bo? gase\s & solid hydroc>bons4 ,be=e be+ us$ x mu/ be ref9$4 ,9 ?is process ! petroleum is run into l>ge iron /ills & subject$ to fractional di/illation4 ,! v>i\s hydroc>bons di/ill ov] 9 ! g5]al ord] ( _! boil+ po9ts4 ,! di/illates :i* collect betwe5 c]ta9 limits ( temp]ature are kept sep>ate & s]ve = diff]5t uses2 !y are fur!r purifi$1 g5]ally by wa%+ ) sulphuric acid1 !n ) an alkali1 & f9ally ) wat]4 ,among ! products obta9$ f crude petroleum 9 ?is way are ! naph?as1 includ+ b5z9e & gasol9e1 k]os5e or coal oil1 lubricat+ oils1 vasel9e1 & p>aff94 ,none ( ^! products are def9ite *emical comp\nds1 b ea* consi/s ( a mixture ( hydroc>bons1 ! boil+ po9ts ( :i* lie )9 c]ta9 limits4 #b4 ,coal t>4 ,?is product is obta9$ 9 ! manufacture ( coal gas1 z already expla9$4 ,x is a complex mixture & is ref9$ by ! same g5]al me?od us$ 9 ref9+ crude petroleum4 ,! pr9cipal hydroc>bons obta9$ f ! coal t> are b5z5e1 tolu5e1 naph?al5e1 & an?rac5e4 ,9 addition to ! hydroc>bons1 coal t> conta9s _m o!r comp\nds1 su* z c>bolic acid & anil9e4 ,prop]ties ( ! hydroc>bons4 ,! l[] memb]s ( ! fir/ two s]ies ( hydroc>bons m5tion$ are all gases2 ! succe$+ memb]s are liquids4 ,9 "s s]ies1 z ! me?ane s]ies1 ! high] memb]s are solids4 ,! prep>ation & prop]ties ( me?ane & acetyl5e h be5 discuss$ 9 a previ\s *apt]4 ,e?yl5e is pres5t 9 small quantities 9 coal gas & may be obta9$ 9 ! laboratory by treat+ alcohol 7,c#b;,h#f,o7 ) sulphuric acid3 ,c#b;,h#f,o ,c#b;,h#d ,h#b,o4 ,b5z5e1 ! fir/ memb] ( ! b5z5e s]ies1 is a liquid boil+ at #hj4 ,! hydroc>bons s]ve z ! mat]ials f :i* a l>ge numb] ( comp\nds c be prep>$2 inde$1 x has be5 propos$ to call organic *emi/ry ! *emi/ry ( ! hydroc>bon d]ivatives4 ,sub/itution products ( ! hydroc>bons4 ,z a rule1 at lea/ a "p ( ! hydrog5 9 any hydroc>bon c be displac$ by an equival5t am\nt ( c]ta9 elem5ts or gr\ps ( elem5ts4 ,?us ! comp\nds ,,*#c;,cl1 ,,*#b;,cl#b1 ,c,h,cl#c1 ,c,cl#d c be obta9$ f me?ane by treatm5t ) *lor9e4 ,su* comp\nds are call$ sub/itution products4 ,*lor(orm 7,c,h,cl#c74 ,?is c be made by treat+ me?ane ) *lor9e1 z j indicat$1 al?\gh a mu* easi] me?od consi/s 9 treat+ alcohol or acetone 7:i* see7 ) blea*+ p[d]4 ,*lor(orm is a heavy liquid hav+ a pleasant odor & a sweeti% ta/e4 ,x is l>gely us$ z a solv5t & z an an/hetic 9 surg]y4 ,iod(orm 7,,*i#c74 ,?is is a yell[ cry/all9e solid obta9$ by treat+ alcohol ) iod9e & an alkali4 ,x has a *>act]i/ic odor & is us$ z an antiseptic4 ,,alcohols ,:5 su* a comp\nd z ,,*#c;,cl is treat$ ) silv] hydroxide ! reaction express$ by ! foll[+ equation takes place3 ,,*#c;,cl ,ag,o,h ,,*#c,,oh ,ag,cl4 ,simil>ly ,c#b;,h#e;,cl w give ,c#b;,h#e,,oh & ,ag,cl4 ,! comp\nds ,,*#c,,oh & ,c#b;,h#e,,oh s obta9$ belong to ! class ( sub/ances kn[n z alcohols4 ,f _! =mulas x w be se5 t !y may be reg>d$ z d]iv$ f hydroc>bons by sub/itut+ ! hydroxyl gr\p 7,,oh7 = hydrog54 ,?us ! alcohol ,,*#c,,oh may be reg>d$ z d]iv$ f me?ane 7,,*#d7 by sub/itut+ ! gr\p ,,oh = "o atom ( hydrog54 ,a great _m alcohols are kn[n1 &1 l ! hydroc>bons1 !y may be gr\p$ into s]ies4 ,! relation betwe5 ! fir/ ?ree memb]s ( ! me?ane s]ies & ! correspond+ alcohols is %[n 9 ! foll[+ table3 ,,*#d 7me?ane7 ,,*#c,,oh 7me?yl alcohol74 ,c#b;,h#f 7e?ane7 ,c#b;,h#e,,oh 7e?yl alcohol74 ,c#c;,h#h 7propane7 ,c#c;,h#g,,oh 7propyl alcohol74 ,me?yl alcohol 7wood alcohol7 7,,*#c,,oh74 ,:5 wood is plac$ 9 an air-tight retort & heat$1 a numb] ( comp\nds are evolv$1 ! mo/ important ( :i* are ! ?ree liquids1 me?yl alcohol1 acetic acid1 & acetone4 ,me?yl alcohol is obta9$ entirely f ?is s\rce1 & on ?is acc\nt is commonly call$ wood alcohol4 ,x is a colorless liquid :i* has a d5sity ( #j4gi & boils at #fg4 ,x burns ) an almo/ colorless flame & is sometimes us$ = heat+ purposes1 9 place ( ! m exp5sive e?yl alcohol4 ,x is a good solv5t = organic sub/ances & is us$ especially z a solv5t 9 ! manufacture ( v>ni%es4 ,x is v poison\s4 ,e?yl alcohol 7common alcohol7 7,c#b;,h#e,,oh74 #a4 ,prep>ation4 ,?is comp\nd may be prep>$ f glucose 7,c#f;,h#ab,o#f71 a sug> easily obta9$ f />*4 ,if "s bak]'s yea/ is add$ to a solution ( glucose & ! temp]ature is ma9ta9$ at ab\t #cj1 bubbles ( gas are soon evolv$1 %[+ t a *ange is tak+ place4 ,! yea/ conta9s a l>ge numb] ( m9ute organiz$ bodies1 :i* are really =ms ( plant life4 ,! plant gr[s 9 ! glucose solution1 & 9 s do+ secretes a sub/ance kn[n z zymase1 :i* breaks d[n ! glucose 9 accordance ) ! foll[+ equation3 ,c#f;,h#ab,o#f #b;,c#b;,h#e,,oh #b;,,co#b4 ,laboratory prep>ation ( alcohol4 ,! =mation ( alcohol & c>bon dioxide f glucose may be %[n z foll[s3 ,ab\t #ajj g4 ( glucose are dissolv$ 9 a lit] ( wat] 9 flask ,a 7,fig4 #ij74 ,?is flask is connect$ ) ! bottle ,b1 :i* is p>tially fill$ ) limewat]4 ,! tube ,c conta9s solid sodium hydroxide4 ,a little bak]'s yea/ is n[ add$ to ! solution 9 flask ,a1 & ! app>atus is connect$1 z %[n 9 ! figure4 ,if ! temp]ature is ma9ta9$ at ab\t #cj1 ! reaction soon beg9s4 ,! bubbles ( gas escape ?r\gh ! limewat] 9 ,b4 ,a precipitate ( calcium c>bonate soon =ms 9 ! limewat]1 %[+ ! pres5ce ( c>bon dioxide4 ,! sodium hydroxide 9 tube ,c prev5ts ! c>bon dioxide 9 ! air f act+ on ! limewat]4 ,! alcohol rema9s 9 ! flask ,a & may be sep>at$ by fractional di/illation4 ,illu/ration3 ,fig4 #ij #b4 ,prop]ties4 ,e?yl alcohol is a colorless liquid ) a pleasant odor4 ,x has a d5sity ( #j4gh & boils at #gh4 ,x resembles me?yl alcohol 9 its g5]al prop]ties4 ,x is sometimes us$ z a s\rce ( heat1 s9ce its flame is v hot & does n deposit c>bon1 z ! flame f oil does4 ,:5 tak5 into ! sy/em 9 small quantities x causes intoxication2 9 l>g] quantities x acts z a poison4 ,! intoxicat+ prop]ties ( su* liquors z be]1 w9e1 & :isky are due to ! alcohol pres5t4 ,be] conta9s f #b to #e ( alcohol1 w9e f #e to #bj1 & :isky ab\t #ej4 ,! ord9>y alcohol ( ! druggi/ conta9s #id ( alcohol & #f ( wat]4 ,:5 ?is is boil$ ) lime & !n di/ill$ ne>ly all ! wat] is remov$1 ! di/illate be+ call$ absolute alcohol4 ,comm]cial prep>ation ( alcohol4 ,alcohol is prep>$ comm]cially f />* obta9$ f corn or potatoes4 ,! />* is fir/ conv]t$ into a sug> kn[n z maltose1 by ! action ( malt1 a sub/ance prep>$ by moi/5+ b>ley ) wat]1 all[+ x to g]m9ate1 & !n dry+ x4 ,!re is pres5t 9 ! malt a sub/ance kn[n z dia/ase1 :i* has ! prop]ty ( *ang+ />* into maltose4 ,?is sug>1 l glucose1 breaks d[n into alcohol & c>bon dioxide 9 ! pres5ce ( yea/4 ,! result+ alcohol is sep>at$ by fractional di/illation4 ,d5atur$ alcohol4 ,! #id alcohol is prep>$ at pres5t at a co/ ( ab\t #ce c5ts p] gallon1 :i* is ab\t half ! co/ ( ! prep>ation ( me?yl alcohol4 ,! gov]nm5t1 h[ev]1 imposes a tax on all e?yl alcohol :i* am\nts to #b4jh p] gallon on ! #id product4 ,?is increases its co/ to su* an ext5t t x is n economical to use x = _m purposes = :i* x is adapt$1 su* z a solv5t 9 ! prep>ation ( pa9ts & v>ni%es & z a mat]ial = ! prep>ation ( _m important organic comp\nds4 ,by an act ( ,congress 9 #aijf1 ! tax 0 remov$ f d5atur$ alcohol1 t is alcohol mix$ ) "s sub/ance :i* r5d]s x unfit = ! purposes ( a bev]age b w n impair its use = manufactur+ purposes4 ,"s ( ! ,european c\ntries h simil> laws4 ,! sub/ances ord9>ily us$ to d5ature alcohol are wood alcohol & pyrid9e1 ! latt] comp\nd hav+ a v (f5sive odor4 ,f]m5tation4 ,! reaction :i* takes place 9 ! prep>ation ( e?yl alcohol belongs to ! class ( *anges kn[n "u ! g5]al "n ( f]m5tation4 ,?us we say t ! yea/ causes ! glucose to f]m5t1 & ! process is kn[n z alcoholic f]m5tation4 ,!re are _m k9ds ( f]m5tations1 & ea* is ?\ght to be due to ! pres5ce ( a def9ite sub/ance kn[n z an enzyme1 :i* acts by catalysis4 ,9 _m cases1 z 9 alcoholic f]m5tation1 ! *ange is br\ght ab\t by ! action ( m9ute =ms ( life4 ,^! probably secrete ! enzymes :i* cause ! f]m5tation to take place4 ,?us ! yea/ plant is suppos$ to br+ ab\t alcoholic f]m5tation by secret+ ! enzyme kn[n z zymase4 ,glyc]9 7,c#c;,h#e7,,oh7#c74 ,?is comp\nd may be reg>d$ z d]iv$ f propane 7,c#c;,h#h7 by displac+ ?ree atoms ( hydrog5 by ?ree hydroxyl gr\ps1 & mu/ !re=e be reg>d$ z an alcohol4 ,x is =m$ 9 ! manufacture ( soaps1 z w be expla9$ lat]4 ,x is an oily1 colorless liquid hav+ a sweeti% ta/e4 ,x is us$ 9 m$ic9e & 9 ! manufacture ( ! explosives nitroglyc]9 & dynamite4 ,,aldehydes ,:5 alcohols are treat$ ) c]ta9 oxidiz+ ag5ts two hydrog5 atoms are remov$ f ea* molecule ( ! alcohol4 ,! result+ comp\nds are kn[n z aldehydes4 ,! relation ( ! aldehydes d]iv$ f me?yl & e?yl alcohol to ! alcohols !mselves may be %[n z foll[s3 ,alcohols ,,*#c,,oh ,correspond+ aldehydes ,,*#b,o ,c#b;,h#e,,oh ,c#b;,h#d,o ,! fir/ ( ^! 7,,*#b,o7 is a gas kn[n z =maldehyde4 ,its aque\s solution is l>gely us$ z an antiseptic & dis9fectant "u ! "n ( =mal94 ,acetaldehyde 7,c#b;,h#d,o7 is a liquid boil+ at #ba4 ,,acids ,l ! o!r classes ( organic comp\nds1 ! organic acids may be arrang$ 9 homolog\s s]ies4 ,"o ( ! mo/ important ( ^! s]ies is ! fatty-acid s]ies1 ! "n hav+ be5 giv5 to x because ! d]ivatives ( c]ta9 ( its memb]s are con/itu5ts ( ! fats4 ,"s ( ! mo/ important memb]s ( ! s]ies are giv5 9 ! foll[+ table4 ,!y are all monobasic1 & ?is fact is express$ 9 ! =mulas by sep>at+ ! replaceable hydrog5 atom f ! re/ ( ! molecule3 ,h,,*o#b =mic acid1 a liquid boil+ at #ajj4 ,h,c#b;,h#c,o acetic acid1 a liquid boil+ at #aah4 ,h,c#c;,h#e,o#b propionic acid1 a liquid boil+ at #adj4 ,h,c#d;,h#g,o#b butyric acid1 a liquid boil+ at #afc4 ,h,c#af;,h#ca,o#b palmitic acid1 a solid melt+ at #fb4 ,h,c#ah;,h#ce,o#b /e>ic acid1 a solid melt+ at #fi4 ,=mic acid 7,h,,*o#b74 ,! "n =mic is d]iv$ f ! ,lat9 =mica1 signify+ ant4 ,?is "n 0 giv5 to ! acid because x 0 =m]ly obta9$ f a c]ta9 k9d ( ants4 ,x is a colorless liquid & occurs 9 _m plants su* z ! /++ nettles4 ,! inflammation caus$ by ! /+ ( ! bee is due to =mic acid4 ,acetic acid 7,h,c#b;,h#c,o#b74 ,acetic acid is ! acid pres5t 9 v9eg>1 ! s\r ta/e be+ due to x4 ,x c be prep>$ by ei!r ( ! foll[+ me?ods4 #a4 ,acetic f]m5tation4 ,?is consi/s 9 ! *ange ( alcohol into acetic acid ?r\gh ! ag5cy ( a m9ute organism commonly call$ "m ( v9eg>4 ,! *ange is repres5t$ by ! foll[+ equation3 ,c#b;,h#e,,oh #b,o ,,hc#b;,h#c,o#b ,h#b,o4 ,! v>i\s k9ds ( v9eg>s are all made by ?is process4 ,9 ! manufacture ( cid] v9eg> ! sug> pres5t 9 ! cid] fir/ und]goes alcoholic f]m5tation2 ! result+ alcohol !n und]goes acetic f]m5tation4 ,! am\nt ( acetic acid pres5t 9 v9eg>s v>ies f #c to #f4 #b4 ,f ! di/illation ( wood4 ,! liquid obta9$ by heat+ wood 9 ! abs5ce ( air conta9s a l>ge am\nt ( acetic acid1 & ?is c be sep>at$ readily 9 a pure /ate4 ,?is is ! mo/ economical me?od = ! prep>ation ( ! conc5trat$ acid4 ,acetic acid is a colorless liquid & has a /rong pung5t odor4 ,_m ( its salts are well-kn[n comp\nds4 ,lead acetate 7,pb7,c#b;,h#c,o#b7b7 is ! ord9>y sug> ( lead4 ,sodium acetate 7,na,c#b;,h#c,o#b7 is a :ite solid l>gely us$ 9 mak+ *emical analyses4 ,copp] acetate 7,cu7,c#b;,h#c,o#b7b7 is a blue solid4 ,:5 copp] is act$ ^u by acetic acid 9 ! pres5ce ( air a gre5 basic acetate ( copp] is =m$4 ,?is is commonly kn[n z v]digris4 ,all acetates are soluble 9 wat]4 ,butyric acid 7,h,c#d;,h#g,o#b74 ,d]ivatives ( butyric acid are pres5t 9 butt] & imp>t to x its *>act]i/ic flavor4 ,palmitic & /e>ic acids4 ,ord9>y fats consi/ pr9cipally ( d]ivatives ( palmitic & /e>ic acids4 ,:5 ! fats are heat$ ) sodium hydroxide ! sodium salts ( ^! acids are =m$4 ,if hydro*loric acid is add$ to a solution ( ! sodium salts1 ! free palmitic & /e>ic acids are precipitat$4 ,!y are :ite solids1 insoluble 9 wat]4 ,/e>ic acid is (t5 us$ 9 mak+ c&les4 ,acids belong+ to o!r s]ies4 ,9 addition to memb]s ( ! fatty-acid s]ies1 m5tion may be made ( ! foll[+ well-kn[n acids4 ,oxalic acid 7,h#b;,c#b,o#d74 ,?is is a :ite solid :i* occurs 9 nature 9 _m plants1 su* z ! sorrels4 ,its ammonium salt 77,,nh#d7b;,c#b,o#d7 is us$ z a reag5t = ! detection ( calcium4 ,:5 add$ to a solution ( a calcium comp\nd ! :ite1 insoluble calcium oxalate 7,ca,c#b,o#d7 precipitates4 ,t>t>ic acid 7,h#b;,c#d;,h#d,o#f74 ,?is comp\nd occurs ei!r 9 a free /ate or 9 ! =m ( its salts 9 _m fruits4 ,! potassium acid salt 7,,khc#d;,h#d,o#f7 occurs 9 ! juice ( grapes4 ,:5 ! juice f]m5ts 9 ! manufacture ( w9e1 ?is salt1 be+ insoluble 9 alcohol1 sep>ates out on ! sides ( ! cask & 9 ?is =m is kn[n z argol4 ,?is is m or less color$ by ! color+ matt] ( ! grape4 ,:5 purifi$ x =ms a :ite solid & is sold "u ! "n ( cream ( t>t>4 ,! foll[+ are also well-kn[n salts ( t>t>ic acid3 potassium sodium t>trate 7,ro*elle salt7 7,k,na,c#d;,h#d,o#f71 potassium antimonyl t>trate 7t>t> emetic7 7,k,sb,o,c#d;,h#d,o#f74 ,cream ( t>t> bak+ p[d]s4 ,! s-call$ cream ( t>t> bak+ p[d]s consi/ ( a mixture ( cream ( t>t>1 bic>bonate ( soda1 & "s />* or fl\r4 ,:5 wat] is add$ to ?is mixture ! cream ( t>t> sl[ly acts ^u ! soda pres5t lib]at+ c>bon dioxide 9 accordance ) ! foll[+ equation3 ,,khc#d;,h#d,o#f ,na,h,c,o#c ,k,na,c#d;,h#d,o#f ,h#b,o ,,co#b4 ,! c>bon dioxide evolv$ escapes ?r\gh ! d\gh1 ?us mak+ x light & por\s4 ,citric acid 7,h#c;,c#f;,h#e,o#g74 ,?is acid occurs 9 _m fruits1 especially 9 lemons4 ,x is a :ite solid1 soluble 9 wat]1 & is (t5 us$ z a sub/itute = lemons 9 mak+ lemonade4 ,lactic acid 7,h,c#c;,h#e,o#c74 ,?is is a liquid :i* is =m$ 9 ! s\r+ ( milk4 ,oleic acid 7,h,c#ah;,h#cc,o#b74 ,! d]ivatives ( ?is acid con/itute ! pr9cipal "p ( _m oils & liquid fats4 ,! acid itself is an oily liquid4 ,,e!real ,,salts ,:5 acids are br\ght 9 contact ) alcohols "u c]ta9 conditions a reaction takes place simil> to t :i* takes place betwe5 acids & bases4 ,! foll[+ equations w s]ve z illu/rations3 ,,koh ,,hno#c ,,kno#c ,h#b,o1 ,,*#c,,oh ,,hno#c ,,*#c,,no#c ,h#b,o4 ,! result+ comp\nds ( :i* me?yl nitrate 7,,*#c,,no#c7 may be tak5 z ! type belong to ! class kn[n z e!real salts1 ! "n hav+ be5 giv5 !m because "s ( !m possess pleasant e!real odors4 ,x w be se5 t ! e!real salts diff] f ord9>y salts 9 t !y conta9 a hydroc>bon radical1 su* z ,,*#c1 ,c#b;,h#e1 ,c#c;,h#e1 9 place ( a metal4 ,! nitrates ( glyc]9 7nitroglyc]974 ,nitric acid reacts ) glyc]9 9 ! same way t x reacts ) a base conta9+ ?ree hydroxyl gr\ps su* z ,fe7,,oh7#c3 ,fe7,,oh7#c #c;,,hno#c ,fe7,,no#c7c #c;,h#b,o1 ,c#c;,h#e7,,oh7#c #c;,,hno#c ,c#c;,h#e7,,no#c7c #c;,h#b,o4 ,! result+ nitrate 7,c#c;,h#e7,,no#c7c7 is ! ma9 con/itu5t ( nitroglyc]91 a slightly yell[i% oil *>act]iz$ by its explosive prop]ties4 ,dynamite consi/s ( por\s e>? :i* has absorb$ nitroglyc]91 & its /r5g? dep5ds on ! am\nt pres5t4 ,x is us$ mu* m l>gely ?an nitroglyc]9 itself1 s9ce x does n explode s readily by concussion & h5ce c be transport$ ) safety4 ,! fats4 ,^! are l>gely mixtures ( ! e!real salts kn[n respectively z ole91 palmit91 & /e>94 ,^! salts may be reg>d$ z d]iv$ f oleic1 palmitic1 & /e>ic acids respectively1 by replac+ ! hydrog5 ( ! acid ) ! glyc]9 radical ,c#c;,h#e4 ,s9ce ?is radical is trival5t & oleic1 palmitic1 & /e>ic acids conta9 only "o replaceable hydrog5 atom to ! molecule1 x is evid5t t ?ree molecules ( ea* acid mu/ ent] into ea* molecule ( ! e!real salt4 ,! =mulas = ! acids & ! e!real salts d]iv$ f ea* are z foll[s3 ,,hc#ah;,h#cc,o#b 7oleic acid7 ,c#h;,h#f7;,c#ah;,h#cc,o#b7c1 7ole97 ,,hc#af;,h#ca,o#b 7palmitic acid7 ,c#c;,h#e7;,c#af;,h#cajb7c 7palmit97 ,,hc#ah;,h#ce,o#b 7/e>ic acid7 ,c#c;,h#e7;,c#ah;,h#ce,o#b7c 7/e>97 ,ole9 is a liquid & is ! ma9 con/itu5t ( liquid fats4 ,palmit9 & /e>9 are solids4 ,butt] fat & oleom>g>9e4 ,butt] fat consi/s pr9cipally ( ole91 palmit91 & /e>94 ,! flavor ( ! fat is due to ! pres5ce ( a small am\nt ( butyr91 :i* is an e!real salt ( butyric acid4 ,oleom>g>9e diff]s f butt] ma9ly 9 ! fact t a small] am\nt ( butyr9 is pres5t4 ,x is made f ! fats obta9$ f cattle & hogs4 ,?is fat is *urn$ up ) milk1 or a small am\nt ( butt] is add$1 9 ord] to furni% suffici5t butyr9 to imp>t ! butt] flavor4 ,saponification4 ,:5 an e!real salt is heat$ ) an alkali a reaction express$ by ! foll[+ equation takes place3 ,c#b;,h#e,,no#c ,,koh ,c#b;,h#e,,oh ,,kno#c4 ,?is process is kn[n z saponification1 s9ce x is ! "o :i* takes place 9 ! manufacture ( soaps4 ,! ord9>y soaps are made by heat+ fats ) a solution ( sodium hydroxide4 ,! reactions involv$ may be illu/rat$ by ! foll[+ equation repres5t+ ! reaction betwe5 palmit9 & sodium hydroxide3 ,c#c;,h#e7;,c#af;,h#ca,o#b7c #c ,na,o,h #c ,na,c#af;,h#ca,o#b ,c#c;,h#e7,,oh7#c4 ,9 accordance ) ?is equation ! e!real salts 9 ! fats are conv]t$ into glyc]9 & ! sodium salts ( ! correspond+ acids4 ,! sodium salts are sep>at$ & con/itute ! soaps4 ,^! salts are soluble 9 wat]4 ,:5 add$ to wat] conta9+ calcium salts ! insoluble calcium palmitate & /e>ate are precipitat$4 ,magnesium salts act 9 a simil> way4 ,x is because ( ^! facts t soap is us$ up by h>d wat]s4 ,,e!rs ,:5 e?yl alcohol is heat$ to #adj ) sulphuric acid ! reaction express$ by ! foll[+ equation takes place3 #b;,c#b;,h#e,,oh 7,c#b;,h#e7b,o ,h#b,o4 ,! result+ comp\nd1 7,c#b;,h#e7b,o1 is ord9>y e!r & is ! mo/ important memb] ( ! class ( comp\nds call$ e!rs4 ,ord9>ily e!r is a light1 v inflammable liquid boil+ at #ce4 ,x is us$ z a solv5t = organic sub/ances & z an an/hetic 9 surgical op]ations4 ,,ketones ,! mo/ common memb] ( ?is gr\p is acetone 7,c#c;,h#f,o71 a colorless liquid obta9$ :5 wood is heat$ 9 ! abs5ce ( air4 ,x is us$ 9 ! prep>ation ( o!r organic comp\nds1 especially *lor(orm4 ,,organic ,,bases ,?is gr\p includes a numb] ( comp\nds1 all ( :i* conta9 nitrog5 z well z c>bon4 ,!y are *>act]iz$ by comb9+ directly ) acids to =m salts1 & 9 ?is respect !y resemble ammonia4 ,!y may1 inde$1 be reg>d$ z d]iv$ f ammonia by displac+ a "p or all ( ! hydrog5 pres5t 9 ammonia by hydroc>bon radicals4 ,among ! simple/ ( ^! comp\nds may be m5tion$ me?ylam9e 7,,*#c,,nh#b7 & e?ylam9e 7,c#b;,h#e,,nh#b74 ,^! two comp\nds are gases & are =m$ 9 ! di/illation ( wood & bones4 ,pyrid9e 7,c#e;,h#f,n7 & qu9ol9e 7,c#i;,h#g,n7 are liquids pres5t 9 small am\nts 9 coal t>1 & also 9 ! liquid obta9$ by ! di/illation ( bones4 ,mo/ ( ! comp\nds n[ classifi$ "u ! g5]al "n ( alkaloids 7:i* see7 also belong to ?is gr\p4 ,,c>bohydrates ,! t]m c>bohydrate is appli$ to a class ( comp\nds :i* includes ! sug>s1 />*1 & alli$ bodies ,^! comp\nds conta9 c>bon1 hydrog51 & oxyg5 ! la/ two elem5ts g5]ally be+ pres5t 9 ! proportion 9 :i* !y comb9e to =m wat]4 ,! mo/ important memb]s ( ?is class are ! foll[+3 ,cane sug> ,c#ab;,h#bb,o#aa4 ,milk sug> ,c#ab;,h#bb,o#aa4 ,dextrose ,c#f;,h#ab,o#f4 ,levulose ,c#f;,h#ab,o#f4 ,cellulose ,c#f;,h#aj,o#e4 ,/>* ,c#f;,h#ajje4 ,cane sug> 7,c#ab;,h#bb,o#aa74 ,?is is ! well-kn[n sub/ance commonly call$ sug>4 ,x occurs 9 _m plants especially 9 ! sug> cane & sug> beet4 ,x 0 =m]ly obta9$ almo/ entirely f ! sug> cane1 b at pres5t ! greate/ am\nt ( x comes f ! sug> beet4 ,! juice f ! cane or beet conta9s ! sug> 9 solution along ) _m impurities4 ,^! impurities are remov$1 & ! result+ solution is !n evaporat$ until ! sug> cry/allizes out4 ,! evaporation is conduct$ 9 clos$ vessels f :i* ! air is p>tially exhau/$4 ,9 ?is way ! boil+ po9t ( ! solution is l[]$ & ! *>r+ ( ! sug> is prev5t$4 ,x is impossible to remove all ! sug> f ! solution4 ,9 prep>+ sug> f sug> cane ! liquors left aft] sep>at+ z mu* ( x z possible f ! juice ( ! cane con/itute ord9>y molasses4 ,maple sug> is made by ! evaporation ( ! sap obta9$ f a species ( ! maple tree4 ,its sweetness is due to ! pres5ce ( cane sug>1 o!r products pres5t 9 ! maple sap imp>t+ ! di/9ctive flavor4 ,:5 a solution ( cane sug> is heat$ ) hydro*loric or o!r dilute m9]al acid1 two comp\nds1 dextrose & levulose1 are =m$ 9 accordance ) ! foll[+ equation3 ,c#ab;,h#bb,o#aa ,h#b,o ,c#f;,h#ab,o#f ,c#f;,h#ab,o#f4 ,?is same *ange is br\ght ab\t by ! action ( an enzyme pres5t 9 ! yea/ plant4 ,:5 yea/ is add$ to a solution ( cane sug> f]m5tation is set up4 ,! cane sug>1 h[ev]1 does n f]m5t directly3 ! enzyme 9 ! yea/ fir/ trans=ms ! sug> into dextrose & levulose1 & ^! sug>s !n und]go alcoholic f]m5tation4 ,:5 heat$ to #afj cane sug> melts2 if ! temp]ature is increas$ to ab\t #bae1 a p>tial decomposition takes place & a br[n sub/ance kn[n z c>amel =ms4 ,?is is us$ l>gely z a color+ matt]4 ,milk sug> 7,c#ab;,h#bb,o#aa74 ,?is sug> is pres5t 9 ! milk ( all mammals4 ,! av]age composition ( c['s milk is z foll[s3 ,wat] #hg4ag ,case9 7nitrog5\s matt]7 #c4ef ,butt] fat #c4fd ,milk sug> #d4hh ,m9]al matt] #j4ge ,:5 r5n91 an enzyme obta9$ f ! /oma* ( calves1 is add$ to milk1 ! case9 sep>ates & is us$ 9 ! manufacture ( *eese4 ,! rema9+ liquid conta9s ! milk sug> :i* sep>ates on evaporation2 x resembles cane sug> 9 appe>ance b is n s sweet or soluble4 ,! s\r+ ( milk is due to ! fact t ! milk sug> pres5t und]goes lactic f]m5tation 9 accordance ) ! equation ,c#ab;,h#bb,o#aa ,h#b,o #d;,c#c;,h#f,o#c4 ,! lactic acid =m$ causes ! sep>ation ( ! case91 ?us giv+ ! well-kn[n appe>ance ( s\r milk4 ,isom]ic comp\nds4 ,x w be obs]v$ t cane sug> & milk sug> h ! same =mulas4 ,_! diff]5ce 9 prop]ties is due to ! diff]5t arrangem5t ( ! atoms 9 ! molecule4 ,su* comp\nds are said to be isom]ic4 ,dextrose & levulose are also isom]ic4 ,dextrose 7grape sug>1 glucose7 7,c#f;,h#ab,o#f74 ,?is sug> is pres5t 9 _m fruits & is commonly call$ grape sug> because ( its pres5ce 9 grape juice4 ,x c be obta9$ by heat+ cane sug> ) dilute acids1 z expla9$ above2 also by heat+ />* ) dilute acids1 ! *ange be+ z foll[s3 ,c#f;,h#ajfe ,h#b,o ,c#f;,h#ab,o#f4 ,pure dextrose is a :ite cry/all9e solid1 readily soluble 9 wat]1 & is n s sweet z cane sug>4 ,9 ! pres5ce ( yea/ x und]goes alcoholic f]m5tation4 ,x is prep>$ f />* 9 l>ge quantities1 & be+ less exp5sive ?an cane sug>1 is us$ z a sub/itute = x 9 ! manufacture ( jellies1 jams1 molasses1 c&y1 & o!r sweets4 ,! product commonly sold "u ! "n ( glucose conta9s ab\t #de ( dextrose4 ,levulose 7fruit sug>77,c#f;,h#ab,o#f74 ,?is sug> is a :ite solid :i* occurs along ) dextrose 9 fruits & honey4 ,x und]goes alcoholic f]m5tation 9 ! pres5ce ( yea/4 ,cellulose 7,c#f;,h#aj,o#e74 ,?is =ms ! basis ( all woody fib]s4 ,cotton & l95 are ne>ly pure cellulose4 ,x is insoluble 9 wat]1 alcohol1 & dilute acids4 ,sulphuric acid sl[ly conv]ts x into dextrose4 ,nitric acid =ms nitrates simil> to nitroglyc]9 9 composition & explosive prop]ties4 ,^! nitrates are v>i\sly kn[n z nitrocellulose1 pyroxyl91 & gun cotton4 ,:5 explod$ !y yield only colorless gases2 h5ce !y are us$ especially 9 ! manufacture ( smokeless gunp[d]4 ,collodion is a solution ( nitrocellulose 9 a mixture ( alcohol & e!r4 ,celluloid is a mixture ( nitrocellulose & camphor4 ,pap] consi/s ma9ly ( cellulose1 ! f9] grades be+ made f l95 & cotton rags1 & ! *eap] grades f /raw & wood4 ,/>* 7,c#f;,h#aj,o#e74 ,?is is by f> ! mo/ abundant c>bohydrate f\nd 9 nature1 be+ pres5t especially 9 se$s & tub]s4 ,9 ! ,unit$ ,/ates x is obta9$ *iefly f corn1 ne>ly #hj ( :i* is />*4 ,9 ,europe x is obta9$ pr9cipally f ! potato4 ,x consi/s ( m9ute granules & is practically insoluble 9 cold wat]4 ,^! granules diff] some:at 9 appe>ance1 accord+ to ! s\rce ( ! />*1 s t x is (t5 possible to det]m9e f :at plant ! />* 0 obta9$4 ,:5 heat$ ) wat] ! granules bur/ & ! />* p>tially dissolves4 ,dilute acids1 z well z c]ta9 enzymes1 conv]t x into dextrose or simil> sug>s4 ,:5 se$s g]m9ate ! />* pres5t is conv]t$ into soluble sug>s1 :i* are us$ z food = ! gr[+ plant4 ,*emical *anges 9 bread mak+4 ,! av]age composition ( :eat fl\r is z foll[s3 ,wat]4 #ac4h ,prote9 7nitrog5\s matt]7 #g4i ,fats #a4d ,/>* #gf4d ,m9]al matt] #j4e ,9 mak+ bread ! fl\r is mix$ ) wat] & yea/1 & ! result+ d\gh set aside 9 a w>m place = a few h\rs4 ,! yea/ fir/ conv]ts a portion ( ! />* into dextrose or a simil> sug>1 :i* !n und]goes alcoholic f]m5tation4 ,! c>bon dioxide =m$ escapes ?r\gh ! d\gh1 mak+ x light & por\s4 ,! yea/ plant ?rives be/ at ab\t #cj2 h5ce ! necessity = hav+ ! d\gh 9 a w>m place4 ,if ! temp]ature rises above #ej1 ! vitality ( ! yea/ is de/roy$ & f]m5tation ceases4 ,9 bak+ ! bread1 ! heat expels ! alcohol & also exp&s ! bubbles ( c>bon dioxide caught 9 ! d\gh1 ?us increas+ its lightness4 ,,"s ,,d]ivatives ,,( ,,b5z5e ,att5tion has be5 call$ to ! complex nature ( coal t>4 ,among ! comp\nds pres5t are ! hydroc>bons1 b5z5e1 tolu5e1 naph?al5e1 & an?rac5e4 ,^! comp\nds are n only useful 9 !mselves b s]ve = ! prep>ation ( _m o!r important comp\nds kn[n "u ! g5]al "n ( coal-t> products4 ,nitrob5z5e 7oil ( myrbane7 7,c#f;,h#e,,no#b74 ,:5 b5z5e is treat$ ) nitric acid a reaction takes place :i* is express$ by ! foll[+ equation3 ,c#f;,h#f ,,hno#c ,c#f;,h#e,,no#b ,h#b,o4 ,! product ,c#f;,h#e,,no#b is call$ nitrob5z5e4 ,x is a slightly yell[i% poison\s liquid1 ) a *>act]i/ic odor4 ,its ma9 use is 9 ! manufacture ( anil9e4 ,anil9e 7,c#f;,h#e,,nh#b74 ,:5 nitrob5z5e is heat$ ) iron & hydro*loric acid ! hydrog5 evolv$ by ! action ( ! iron ^u ! acid r$uces ! nitrob5z5e 9 accordance ) ! foll[+ equation3 ,c#f;,h#e,,no#b #f;,h ,c#f;,h#e,,nh#b #b;,h#b,o4 ,! result+ comp\nd is kn[n z anil9e1 a liquid boil+ at #ahb4 ,:5 fir/ prep>$ x is colorless1 b d>k5s on /&+4 ,l>ge quantities ( x are us$ 9 ! manufacture ( ! anil9e or coal-t> dyes1 :i* include _m important comp\nds4 ,c>bolic acid 7,c#f;,h#e,,oh74 ,?is comp\nd1 sometimes kn[n z ph5ol1 occurs 9 coal t>1 & is also prep>$ f b5z5e4 ,x =ms colorless cry/als :i* are v soluble 9 wat]4 ,x is /rongly corrosive & v poison\s4 ,naph?al5e & an?rac5e4 ,^! are hydroc>bons occurr+ along ) b5z5e 9 coal t>4 ,!y are :ite solids1 insoluble 9 wat]4 ,! well-kn[n mo? balls are made ( naph?al5e4 ,l>ge quantities ( naph?al5e are us$ 9 ! prep>ation ( indigo1 a dye =m]ly obta9$ f ! indigo plant1 b n[ l>gely prep>$ by laboratory me?ods4 ,simil>ly an?rac5e is us$ 9 ! prep>ation ( ! dye aliz>91 :i* 0 =m]ly obta9$ f ! madd] root4 ,,! ,,alkaloids ,?is t]m is appli$ to a gr\p ( comp\nds f\nd 9 _m plants & trees4 ,!y all conta9 nitrog51 & mo/ ( !m are *>act]iz$ by _! p[] to comb9e ) acids to =m salts4 ,?is prop]ty is indicat$ by ! "n alkaloids1 :i* signifies alkali-l4 ,! salts are soluble 9 wat]1 & on ?is acc\nt are m l>gely us$ ?an ! free alkaloids1 :i* are insoluble 9 wat]4 ,_m ( ! alkaloids are us$ 9 m$ic9e1 "s ( ! m important ones be+ giv5 bel[4 ,qu99e4 ,?is alkaloid occurs along ) a numb] ( o!rs 9 ! b>k ( c]ta9 trees :i* gr[ 9 di/ricts 9 ,s\? ,am]ica & also 9 ,java & o!r tropical isl&s4 ,x is a :ite solid1 & its sulphate is us$ 9 m$ic9e 9 ! treatm5t ( fev]s4 ,morph9e4 ,:5 incisions are made 9 ! unripe capsules ( "o ( ! v>ieties ( ! poppy plant1 a milky juice exudes :i* soon ?ick5s4 ,?is is remov$ & p>tially dri$4 ,! result+ sub/ance is ! ord9>y opium :i* conta9s a numb] ( alkaloids1 ! pr9cipal "o be+ morph9e4 ,?is alkaloid is a :ite solid & is ( great s]vice 9 m$ic9e4 ,among ! o!r alkaloids may be m5tion$ ! foll[+3 ,nicot9e1 a v poison\s liquid1 ! salts ( :i* occur 9 ! leaves ( ! tobacco plant2 coca9e1 a cry/all9e solid pres5t 9 coca leaves & us$ 9 m$ic9e z a local an/hetic2 atrop9e1 a solid pres5t 9 ! b]ry ( ! deadly night%ade1 & us$ 9 ! treatm5t ( diseases ( ! eye2 /ry*n9e1 a :ite1 int5sely poison\s solid pres5t 9 ! se$s ( ! memb]s ( ! ,/ry*nos family4 ,,index ,acetaldehyde #dje ,acetic acid #djf ,acetone #daa ,acetyl5e #bjc s]ies #cii ,acids #ajf b9>y #aac *>act]i/ics #ajf def9ition #ajg dibasic #aei famili> #ajf monobasic #aei nom5clature #aac organic #dje prep>ation #ada /r5g? #aaa t]n>y #aac undissociat$ #ajg ,ack] furnace1 #bgi ,agate #bfj ,air #hc a me*anical mixture #hi c>bon dioxide 9 #hg *anges 9 composition #hg liquid #ia nitrog5 9 #hg oxyg5 9 #he poison\s effects ( exhal$ #hh prop]ties #ij quantitative analysis ( #he reg>d$ z an elem5t #hc /&>d = d5sity #bbi wat] vapor 9 #hg ,alaba/] #cjh ,al*emi/s #i ,al*emy #i ,alcohol1 common #djb d5atur$ #djd e?yl #djb me?yl #djb wood #djb ,alcohols #dja ,aldehydes #dje ,aliz>9 #dah ,alkali #ajg1 #bgd family #bgd ,alkal9e-e>? family #cjj ,alkaloids #dah ,allotropic =ms #bb ,alloys #beb ,alum #ccc ammonium #ccd ammonium *rome #chd ammonium iron #ceb bak+ p[d]s #cce potassium #ccc potassium *rome #chd potassium iron #ceb ,alum9ates #ccb ,alum9ium #cbg bronze #ccj1 #cei *loride #ccc family #cbg hydroxide #ccb metallurgy #cbh occurr5ce #cbg oxide #cca prep>ation #cbh prop]ties #cbi silicates #cce uses #ccj ,amalgam #cfb ,ame?y/ #bfj1 #cca ,ammonia #abc composition #abg prep>ation #abc prop]ties #abd uses #abe ,ammonium #abf acid c>bonate #bie c>bonate #bie *loride #bid comp\nds #bid ,ammonium hydrosulphide #bif hydroxide #abf molybdate #chh oxalate #djg sulphate #bie sulphide #bie sulphide1 yell[ #bif ,analysis #dj ,anhydride #ace c>bonic #bjf *romic #chg nitric #ace nitr\s #ace phosphoric #bdc sulphuric #aec ,anhydrite #bhh ,anil9e #dag ,anion #ajf ,anode #ii ,an?rac5e #dah ,antimony #bej acids #bea alloys #bec *loride #beb metallic prop]ties #beb occurr5ce #bea oxides #bea prep>ation #bea prop]ties #bea sulphides #bea ,apatite #age1 #bci1 #caa ,aqua ammonia #abd ,aqua regia #ahe ,aque\s t5sion #be ,argon #hj ,ars5ic #bdf acids #bej antidote #bej ,m>%'s te/ #bdh occurr5ce #bdf oxides #bdi prep>ation #bdf prop]ties #bdg sulphides #bej :ite #bdi ,ars5opyrites #bdf ,ars9e #bdg ,asbe/os #cba1 #ccf ,atmosph]e #hc con/itu5ts #hc function ( con/itu5ts #hd ,atomic hypo!sis #fa !ory #ei & laws ( matt] #fc & radium #cad weights1 #fe accurate det]m9ation #bca & g5]al prop]ties #afg & specific heats #bcc calculation ( #bca ,dalton's me?od #bbc direct det]m9ation #bcc f molecul> weights #bcj relation to equival5t #bbd /&>d = #ff /eps 9 det]m9+ #bbd ,atoms #fb size #fe ,atrop9e #dai ,aurates #cif ,avogadro's hypo!sis #bbf & *emical calculations #bce & molecul> weights #bbg ,azote #gh ,azurite #ceg ,babbitt metal #bec ,bact]ia #he decomposition ( organic matt] by #abb nitrify+ #he ,bak+ p[d]s #bhe1 #djh alum #cce soda #bhe ,b>ium #cab *loride #cac nitrate #cac oxides #cab sulphate #cac ,b>ytes #cab ,bases #ajg *>act]i/ics #ajg def9ition #ajh famili> #ajg nom5clature #aac organic #dab /r5g? #aac undissociat$ #ajh ,basic l9+ process #cdf ,bauxite #ccb ,be] #djd ,b5z5e #dag d]ivatives #dag s]ies #cii ,b5z9e #djj ,bessem] process #cde ,bismu? #bec basic salts #bee *loride #bec nitrate #bec occurr5ce #bec oxides #bed prep>ation #bec salts1 hydrolysis ( #bed subnitrate #bef uses #bec ,bismu?yl *loride #bef ,bla/ furnace #cda lamp #ch ,blea*+ p[d] #cjf ,blea*+ by *lor9e #aha by sulphur\s acid #aeb ,boil] scale #cbj ,bone a% #caa ,bone black #bjj ,borax #bfe bead #bff ,bornite #ceg ,boron #beg1 #bfd acids #bfe fluoride #bfd hydride #bfd occurr5ce #bfd oxides #bfd prep>ation #bfd prop]ties #bfd ,brass #cbc ,bread mak+ #daf ,bromides #aij ,brom9e #ahg occurr5ce #ahg oxyg5 comp\nds #aij prep>ation #ahg prop]ties #ahh ,bronze #cei alum9ium #ccj1 #cei ,butt] fat #daj ,butyric acid #djg ,by-product #bhd ,cadmium #cbe comp\nds #cbf ,csium #bid ,calam9e #cba ,calcite #cje ,calcium #cja c>bide #bjc1 #caj c>bonate #cje *loride #cjf fluoride #cjh hydroxide #cjc occurr5ce #cja oxide #cjb phosphate #bdf1 #caa prep>ation #cjb sulphate #cjh ,calomel #cfc ,calorie #gf ,c>amel #dad ,c>bohydrates #dac ,c>bolic acid #dag ,c>bon #aif allotropic =ms #aif amorph\s #aih comp\nds #aif cry/all9e =ms #aig cycle 9 nature #hh dioxide #bjd & bases #bjf & plant life #hh 9 air #hg occurr5ce #bjd prep>ation #bjd prop]ties #bjd solid #bjd disulphide #afj1 #baj family #aif hydrog5 comp\nds #bja monoxide #bjh occurr5ce #aif oxides #bjc prop]ties #bjj pure #aih retort #aii uses #bjj ,c>bonates #bjg acid #bjg ,c>bonic acid #bjf ,c>borundum #bei ,c>nallite #bhh ,case9 #dad ,cassit]ite #cgj ,catalysis #aec ,catalyz]s #aec ,ca?ode #ii ,cation #ajf ,cau/ic pota% #bhh soda #bgh ,cele/ite #cab ,celluloid #dae ,cellulose #dae ,cem5t #cjd ,c]amic indu/ries #ccf ,c]ium #cgg ,*alc$ony #bfj ,*alcocite #ceg ,*alcopyrite #ceg ,*alk #cje ,*amb] acid #aeg ,*anges1 physical & *emical #b ,*>coal #aii ,*emical aff9ity #ab *anges #b comp\nds #g equilibrium #abh prop]ties #c ,*emi/ry1 def9ition #d ,*ili saltpet] #aia1 #bhe ,*9aw>e #ccf ,*loric acid #ahg ,*lorides #ahf ,*lor9e #agg blea*+ action #aha *emical prop]ties #ahj family #agd hi/orical #agg occurr5ce #agh oxides #ahg oxyg5 acids #ahg prep>ation #agh prop]ties #agi ,*lor(orm #dja ,*loroplat9ic acid #cic ,*lor\s acid #ahg ,*romates #che ,*rome alum #chd ,*romic acid #chh anhydride #chg *loride #chc hydroxide #chc sulphate #chd sulphide #chd ,*romite #chc ,*romium #chc a base-=m+ elem5t #chc an acid-=m+ elem5t #che occurr5ce #chc ,c9nab> #cfc ,citric acid #djh ,clay #ccf ,coal #aii gas #bag products #djj t> #bah ,cobalt #ced comp\nds #ced ,coca9e #dai ,coke #aii ,collodion #dae ,colemanite #bfe ,comb9+ weights #bbe ,combu/ion #ag broad s5se #bj 9 air #ai phlogi/on !ory #ai products #ah spontane\s #bj support]s #bac ,comp\nds1 *emical #g isom]ic #dad ( metals1 prep>ation #bfe /ructure ( #aah ,cons]vation ( en]gy #d ( matt] #e ,contact process #aed ,conv]t]1 ,bessem] #cde ,copp] #ceg acetate #djg alloys ( #cei family #cef hydroxide #cfj metallurgy #ceg occurr5ce #ceg ores #ceg oxide #cfj prop]ties #ceh ref9+ #ceh sulphate #cfa sulphide #cfa uses #cei ,copp]as #cej ,coral #cje ,corrosive sublimate #cfc ,corundum #cca ,cream ( t>t> #djh ,crocoisite #chc ,cryolite #age1 #cbh ,cry/allization #ih wat] ( #ed1 #ge ,cry/allography #afa ,cry/als #afa axes ( #afa sy/ems #afb ,cupric comp\nds #cfj ,cuprite #cfj ,cupr\s comp\nds #cfj *loride #cfj oxide #cfj ,cyanides #baj solutions are alkal9e #baj ,dalton's atomic hypo!sis #fa ,decay #ba ,decomposition ( organic matt] #abb ,decrepitation #ee ,deliquesc5ce #ee ,d5sity ( gases #bcj ,desiccat+ ag5ts #ee ,develop]s #cfg ,dew> bulb #ia ,dextrose #dad ,diamond #aig ,di*romates #che ,di*romic acid #che ,dimorph\s sub/ances #afc ,dissociation #ii & boil+ po9t #aja & freez+ po9t #aja equations ( #aab ext5t ( #aac ,di/illation #ej ,dogtoo? sp> #cjf ,dolomite #cai ,d\ble decomposition #ga ,drummond light #ch ,dye+ #ccc ,dynamite #dji ,e>? metals #cbg ,effloresc5ce #ed ,electric furnace #bba ,electro-*emical indu/ries #bfi ,electrode #ii ,electrolysis #ii ( sodium *loride #ajb ( sodium sulphate #ajc ( wat] #da1 #ajb ,electrolytes #ii ,electrolytic dissociation #ii ,electroplat+ #cff ,electrotyp+ #cei ,elem5ts1 def9ition #h atomic weights #bcb e>li] classification #afe names #aa natural gr\ps #afe numb] ( #i occurr5ce #aj p]iodic division #aff physical /ate #aj symbols ( #aa ,em]y #cca ,en]gy #d & plant life #hi *emical #e cons]vation ( #d trans=mation ( #e ,enzyme #dje ,epsom salts #cbj ,equations #fh are quantitative #gb k requisite = #fi n algebraic #gd read+ ( #fi ,equilibrium #ach *emical #ach 9 solution #aci po9t ( #ach ,equival5t #bbd det]m9ation ( #bbd elem5ts ) m ?an "o #bbe relation to atomic weight #bbd ,et*+ #agg ,e!r #daa ,e!real salts #dji ,e!rs #daa ,e?ylam9e #dab ,e?yl5e s]ies #cii ,eudiomet] #dc ,evaporation #aa ,families 9 p]iodic gr\ps #agj triads #afe ,family resemblances #agj ,fats #dji ,fatty acid s]ies #dje ,feldsp> #bfa1 #cce ,f]m5tation #djd acetic #djf alcoholic #djd1 #dje lactic #dad ,f]ric *loride #ceb hydroxide #ceb salts #cea r$uction #cec sulphate #ceb ,f]ro*romium1 #chc ,f]romanganese #cdc ,f]rosilicon #bei ,f]r\s c>bonate #cea salts #cej oxidation ( #cec sulphate #cej sulphide #cej ,f]tiliz]s #bde ,filtration #f1 #ea b$s #eb ,fire damp #bjb ,flames #bac appe>ance #bad bl[pipe #baf ,buns5 #bad conditions = #bac hydrog5 #cd lum9osity #baf oxidiz+ #bad oxyhydrog5 #cg reactions #bif r$uc+ #bad /ructure #bad ,fla% lights #cag ,fl9t #bfj ,fluorides #agg ,fluor9e #age ,fluorsp> #age1 #cjh ,fluosilicic acid #bei ,flux #cdj ,fool's gold #cea ,=maldehyde #dje ,=mal9 #dje ,=mic acid #djf ,=mulas #fh h[ det]m9$ #bcd /ructural #aai ,fractional di/illation #ea ,frankl9ite #cba ,fuels #bbj ,furnace1 arc #bba electric #bba resi/ance #bba ,fusion me?ods #bga ,gal5a #cgc ,gallium #cbg ,galvaniz$ iron #cbc ,gas1 collection ( #ae coal #bag fuel #bag illum9at+ #bag measurem5t ( #bc natural #bai purification ( #bah wat] #bai ,gases1 table #bbj ,gasol9e #djj ,g]man silv] #cbc1 #cei ,g]manium #cgj ,g]ms1 effect ( cold on #ec 9 air #hd 9 wat] #eb ,glass #bfb color+ ( #bfc et*+ ( #agg mold+ ( #bfc nature ( #bfc v>ieties #bfc ,glaub]'s salt #bha ,glaz+ #ccf ,glucose #dad ,glyc]9 #dje nitrates ( #dji ,gold #cic alloys #cif *loride #cif co9 #cei extraction ( #cid 9 copp] #ceh m9+ #cid occurr5ce #cic prop]ties #cif ref9+ ( #cie telluride #cid ,golds*midt me?od #bfi1 #ccj ,gram-molecul> weight #bcf ,granite #ccf ,graphite #aih ,gun cotton #dae metal #cei p[d] #bib ,gypsite #cjh ,gypsum #cjh ,halog5s #agd ,h>d wat] #cji ,heat ( reaction #ge ,helium #hj1 #cad ,hematite #cci1 #cdi ,homolog\s s]ies #cih ,hydriodic acid #aic ,hydrobromic acid #ahi ,hydroc>bons #bja1 #cih prop]ties #djj s]ies #cih sub/itution products #dja ,hydro*loric acid #ahb composition #ahc oxidation ( #ahe prep>ation #ahb prop]ties #ahd salts #ahf ,hydrocyanic acid #baj ,hydr(luoric acid #agf et*+ by #agg salts ( #agg ,hydrog5 #bh dioxide #ef explosive ) oxyg5 #ce occurr5ce #bh prep>ation f acids #cj prep>ation f wat] #bh prop]ties #cb /&>d = atomic weights #ff /&>d = molecul> weights #bbg sulphide #adf uses #ch ,hydrolysis #bed conditions affect+ #bee p>tial #bee ,hydrosulphuric acid #adf ,hydroxyl radical #aab ,hypo*lor\s acid #ahg ,hypo!sis #fa ,avogadro's #bbf ,dalton's #fa ,ice manufacture #abe ,icel& sp> #cje ,indigo #dah ,indium #cbg ,insoluble comp\nds #bgb ,iodic acid #aid ,iodides #aic ,iod9e #aij oxyg5 comp\nds #aic prep>ation #aia prop]ties #aib t9cture #aib ,iod(orm #aib1 #dja ,ions #ajj & electrolytes #ajd ,iridium #cic ,iron #cci alum #ceb ca/ #cdc comp\nds #cdi cyanides #ceb disulphide #cea family #cch metallurgy #cci occurr5ce #cci ores #cci oxides #cdi pure #cdh v>ieties #cdb1 #cdg wr\ght #cdc ,jasp] #bfj ,ka9ite #bhh ,kaol9 #bfa1 #cce ,k]os5e #djj ,ketones #daa ,kies]ite #bhh ,k9dl+ temp]ature #ag ,krypton #hj ,lactic acid #djh ,lampblack #bjj ,laugh+ gas #acb ,law1 def9ition #fa ( ,boyle #bd ( ,*>les #bc ( comb9+ volumes #aid ( cons]vation ( en]gy #d ( cons]vation ( matt] #e1 #ei ( def9ite composition #ei ( ,dulong & ,petit #bcc ( ,gay-,lussac #aid ( multiple proportion #fj ( ,ra\lt #bcc p]iodic #afi ,lead #cgc acetate #cge1 #djg alloys #cge basic c>bonate #cgf c>bonate #cgf *loride #cgg *romate #cgg insoluble comp\nds #cgf metallurgy #cgc nitrate #cge occurr5ce #cgc oxides #cge p]oxide #cge prop]ties #cgd r$ #cge soluble salts #cge sug> ( #cge sulphate #cgg sulphide #cgg :ite #cgf ,le ,blanc soda process #bhb ,levulose #dae ,lime #cjb air-slak$ #cjc hypo*lorite #cjg kilns #cjc slak$ #cjc ,lime light #ch ,lime/one #cje ,limewat] #cjc ,limonite #cci ,li?>ge #cge ,li?ium #bid ,lum9osity ( flames #baf ,lun> cau/ic #cff ,magnesia #cah alba #cai u/a #cah ,magnesite #cah ,magnesium #cag basic c>bonate #cai c>bonate #cah cem5t #cah *loride #cai family #caf hydroxide #cah oxide #cah silicates #cba sulphate #cbj ,magnetite #cci1 #cdi ,mala*ite #ceg ,manganates #cha ,manganese #cgi a base-=m+ elem5t #chj an acid-=m+ elem5t #cha 9 glass #bfc occurr5ce #cgi oxides #chj ,manganic acid #cha ,mangan\s salts #chj ,m>ble #cje ,m>l #cje ,m>% gas #bjb ,mat*es #bdb ,matte #ceh ,matt]1 classification #f cons]vation #e def9ition #e k9ds #i ,measurem5t ( gases #bc ,me*anical mixtures #f ,me]s*aum #cba1 #ccf ,m]curic *loride #cfc iodide #cfd oxide #ad1 #cfb sulphide #cfc ,m]cur\s *loride #cfc ,m]cury #cfa iodides #cfd metallurgy #cfa occurr5ce #cfa oxides #cfb uses #cfb ,metaboric acid #bfe ,metallurgy #bfh ,metals #afe1 #bfg action on salts #bga def9ition #bfg extraction #bfh occurr5ce #bfg prep>ation ( comp\nds #bfi r$uction f ores #bfh ,metaphosphoric acid #bde ,met>s5ic acid #bej ,metasilicic acid #bfa ,meta/annic acid #cga ,me?ane #bjb1 #cii ,me?ylam9e #dab ,mexican onyx #cje ,mica #bfa1 #ccf ,microcosmic salt #bdd ,milk #dad ,m9]als #bfg ,m9ium #cge ,mix$ salts #bdd ,molasses #dac ,molecul> weights #bbf boil+-po9t me?od #bcc comp>$ ) oxyg5 #bbh det]m9ation #bbf freez+-po9t me?od #bcc oxyg5 /&>d #bbg ( elem5ts #bcb vapor-d5sity me?od #bbi ,molecule #fb ,molybd5um #chh ,molybdic acid #chh ,monazite s& #cgg ,mordants #ccc ,morph9e #dah ,mort> #cjd ,mo? balls #dah ,muriatic acid #ahb ,naph?al5e #dah ,naph?as #djj ,nasc5t /ate #ahb ,natural gas #bai sci5ces #a ,neon #hj ,neutralization #ajh a def9ite act #aji def9ition #aji heat ( #aji p>tial #aaa ,niag>a ,falls #bfi1 #cbi ,nickel #ced co9 #cei comp\nds #ced plat+ #ced ,nicot9e #dai ,nitrates #aca ,nitric acid1 #abh action on metals #acj decomposition #abi oxidiz+ action #acj prep>ation #abh1 #adj prop]ties #abi salts #aca ,nitric oxide #acc ,nitrites #acb ,nitrob5z5e #dag ,nitrocellulose #dae ,nitrog5 #gh comp\nds #abb 9 air #hg occurr5ce #gh1 #abb oxides #acb prep>ation #gh prop]ties #hj ,nitroglyc]9 #dji ,nitrosulphuric acid #aee ,nitr\s acid #acb oxide #acb ,non-metals #afe ,oil ( myrbane #dag ( vitriol #aed ,oleic acid #djh ,ole9 #dji ,oleom>g>9e #daj ,onyx #bfj ,opal #bfj ,op5-he>? process #cdf ,opium #dah ,ores #bfg ,organic bases #dab *emi/ry #bja1 #cig matt]1 decomposition #abb ,orpim5t #bdf ,or?o>s5ic acid #bej ,or?ophosphates #bdd ,or?ophosphoric acid #bdd ,or?osilicic acid #bfa ,osmic acid #cic ,osmium #cic tetroxide #cic ,oxalic acid #djg ,oxidation #ag1 #cec def9ition #ah ,oxidiz+ ag5t #cg ,oxyg5 #ac & ozone #bb comm]cial prep>ation #af hi/ory #ac importance #ba 9 air e/imation1 #he 9 air function1 #hd occurr5ce #ac prep>ation #ac prop]ties #af /&>d = atomic weights #ff two atoms 9 molecule #bbg ,oxyhydrog5 bl[pipe #cg ,ozone #ba1 #acg ,palladium #cij ,palmitic acid #djg ,palmit9 #dji ,p>aff9 #djj ,p>is gre5 #bej ,p>kes's me?od = silv] #cfd ,pe>ls #cje ,p]*loric acid #ahg ,p]iodic acid #aid ,p]iodic division #aff gr\ps #afg law #afi law1 imp]fections #agb law1 value #aga table #afh table1 arrangem5t #aff ,p]man5t h>dness #caj ,p]manganates #cha ,p]manganic acid #cha ,p]oxides #bgh ,petroleum #cii ,pewt] #cgb ,ph5ol #dag ,philosoph]'s /one #i ,phlogi/on #ai ,phosphates #bde ,phosph9e #bdb ,phosphonium comp\nds #bdc ,phosphoric acid #bdd ,phosphorite #bci ,phosphor\s acid #bdd ,phosphorus #bci acids #bdc family #bch hydrog5 comp\nds #bdb occurr5ce #bci oxides #bdc prep>ation #bci prop]ties #bdj r$ #bda yell[ #bdj ,photography #cfg ,physical *anges #b prop]ties #c prop]ties & p]iodic gr\ps #aga /ate #c ,physics #a1 #d ,pit*bl5de #cad ,pla/] ( ,p>is #cjh ,plat9ic *loride #cic ,plat9iz$ asbe/os #cia ,plat9\s *loride #cic ,plat9um #cia a catalytic ag5t #aeb1 #cib ,pneumatic tr\gh #af ,polyboric acid #bfe ,polyhalite #bhh ,polysilicic acids #bfa ,porcela9 #ccf ,portl& cem5t #cjd ,pota% #bic ,potassium #bhg acid c>bonate #bid acid sulphate #bid acid sulphite #bid alum1 alum9ium #ccd alum1 *rome #chd alum1 iron #ceb & plant life #bhg aurate #cif bromide #bij c>bonate #bic *lorate #bia *loride #bij *romate #che cyanide #bic di*romate #chf f]ricyanide #ceb f]rocyanide #ceb hydroxide #bhh hydroxide1 action ( halog5s #bhi hypo*lorite #bhi iodide #bij manganate #cha nitrate #bia occurr5ce #bhg p]manganate #cha prep>ation #bhh sulphate #bid ,precipitat$ *alk #cjf ,precipitation #adj ,prop]ties1 *emical #c physical #c ,prussic acid #baj ,puddl+ #cdc furnace #cdd ,pyrid9e #dab ,pyrites #cea ,pyrolusite #chj ,pyrophosphoric acid #bde ,quantitative equations #gb ,qu>tz #bfj ,quicklime #cjb ,qu99e #dah ,qu9ol9e #dab ,radical #aab ,radium #cac ,reaction1 classes #gj addition #gj complet$ #aci heat ( #ge ( decomposition #gj ( d\ble decomposition #ga ( sub/itution #gj rev]sible #acg /eps 9 #aca ,realg> #bdf ,r$ lead #cge phosphorus #bda ,r$uc+ ag5t #cg ,r$uction #cf1 #ced ,r5n9 #dad ,resemblances1 family #agj ,respiration #hg ,rhodium #cij ,ro*elle salts #djh ,r\ge #cdi ,rubidium #bid ,ruby #cca ,ru!nium #cij ,rutile #bfd ,safety lamp #bjb ,sal ammoniac #bid soda #bhb ,salt #bhj ,saltpet] #bia ,*ili #bhe ,salts1 #aji acid1 #aab ,salts basic #aaa b9>y #aad *>act]i/ics #aji def9ition #aji insoluble #bgb mix$ #bdd nom5clature #aac normal #aab prep>ation by precipitation #bgj ,s& #bfj ,s&/one #bfj ,saponification #daj ,sapphire #cca ,sat9sp> #cjh ,scale #cbj ,s*nite #bhh ,sel5ite #cjh ,sel5ium #afa ,s]p5t9e #cbj1 #ccf ,%ot #bdg1 #cge ,sid]ite #cci ,silica #bfj ,silicates #bfa ,silicic acids #bfa ,silicides #bei ,silicon #beh acids #bfa dioxide #bfj fluoride #beh hydride #beh ,silv] #cfd amalgamation process #cfd bromide #cfg *loride #cfg co9 #cei ,g]man #cei 9 copp] ores #ceh iodide #cfg metallurgy #cfd nitrate #cff oxide #cff p>t+ ( #cfe ref9+ #cfe sulphide #cff ,slag #cdj ,smalt #cee ,smi?sonite #cba ,smokeless p[d] #bic ,soaps #daj ,soda a% #bhd ,soda lime #bjb ,sodium #bgf acetate #djg bic>bonate #bhe c>bonate #bhb c>bonate1 hi/orical #bhd *loride #bhj *romates #chf hydrog5 c>bonate #bhe hydroxide #bgh hyposulphite #bhb iodate #aia nitrate #bhe occurr5ce #bgf p]oxide #bgg phosphates #bhf prep>ation #bgf prop]ties #bgg sulphate #bha sulphite #bha tetraborate #bhg ?iosulphate #bhb ,sold] #cgb1 #cge ,solubility ( gases #ie ( solids #if ,solution #id & *emical action #ec boil+ po9t #ih classes #id di/ribution ( solids 9 #ih electrolysis ( #ii freez+ po9t #ii ( gases 9 liquids #id ( solids 9 liquids #if prop]ties #ih saturat$ #ig sup]saturat$ #ih ,solvay soda process #bhc ,sombr]ite #bci ,spectroscope #bif ,sphal]ite #cbe ,spiegel iron #cdc ,sp9el #ccb ,spontane\s combu/ion #bj ,/alactites #cje ,/alagmites #cje ,/&>d conditions #bc ,/annates #cgb ,/annic acid #cgb *loride #cgb oxide #cgb ,/ann\s *loride #cgb ,/>* #dae ,/assfurt salts #bhg ,/e>ic acid #djg ,/e>9 #dji ,/eel #cde alloys #cdh prop]ties #cdg temp]+ ( #cdh tool #cdg ,/ib9e #bea ,/ibnite #bej ,/onew>e #ccf ,/rontianite #cab ,/rontium #cab hydroxide #cab nitrate #cab ,/ructural =mulas #aai ,/ructure ( comp\nds #aai ,/ry*n9e #dai ,sub/itution #gj ,sug>s #dab cane #dab fruit #dae grape #dad milk #dad ,sulphates #aei ,sulphides #adh ,sulphites #aeb action ( acids on #aej ,sulphur #adc allotropic =ms #add *emical prop]ties #ade comp>ison ) oxyg5 #afa dioxide #adi prep>ation #adi prop]ties #aej extraction #adc fl[]s ( #adc occurr5ce #adc oxides #adi physical prop]ties #add trioxide #aeb uses #adf v>ieties #add ,sulphuric acid #aed action z an acid #aeg action on metals #aeg action on organic matt] #aeh action on salts #aeh action on wat] #aeh fum+ #aee manufacture #aed oxidiz+ action #aeg plant #aef prop]ties #aeg salts #aei ,sulphuric anhydride #aec ,sulphur\s acid #aea ,sup]phosphate ( lime #bdf ,sylv9e #bhh ,symbols #aa ,syn!sis #dj ,table1 alkali metals #bgd alkal9e-e>? metals #cjj alloys ( copp] #cei aque\s t5sion ,app5dix ,b atomic weights ,app5dix ,a *lor9e family #agd composition ( e>?'s cru/ #aj composition ( fuel gases #bbj con/ants ( elem5ts ,app5dix ,b copp] family #cef elem5ts ,app5dix ,a gold & plat9um metals #cij hydroc>bons #cii magnesium family #caf manganese & *romium #cgi p]iodic arrangem5t #afh phosphorus family #bch silicon family #beg solubility ( gases 9 wat] #ie solubility ( salts #if solubility ( salts at diff]5t temp]atures #ig t9 & lead #cgj weights ( gases ,app5dix ,b ,talc #cba1 #ccf ,t>t> emetic #djh ,t>t>ic acid #djh ,tellurium #afa ,tempor>y h>dness #cji ,t]n>y acids #aac salts #aad ,tetraboric acid #bfe ,?allium #cbg ,!ory1 atomic #fa def9ition #fd value ( #fd ,!rmite #cca ,?io comp\nds #bhb ,?iosulphates #aei ,?iosulphuric acid #aei ,?orium #cgg ,t9 #cgj block #cga comp\nds #cgb cry/als #cgb family #cgj foil #cga metallurgy #cgj plate #cga prop]ties #cga uses #cga ,titanium #beg1 #bfd ,topaz #cca ,triad families #aff ,tung/5 #chh ,type metal #bec1 #cge ,uranium #chh ,val5ce #aaf a num]ical prop]ty #aaf & comb9+ ratios #aah & equations #abj & =mulas #abj & p]iodic gr\ps #afb & /ructure #aah def9ition #aaf indirectly det]m9$ #aag measure ( #aag v>iable #aag ,vasel9e #djj ,v5etian r$ #cdi ,v]digris #djg ,v]milion #cfc ,v9eg> #djf ,vitriol1 blue #cfa gre5 #cej oil ( #aed :ite #cbd ,volume & aque\s t5sion #be & pressure #bd & temp]ature #bc ( comb9+ gases #aid ,wat] #dj a comp\nd #dj & disease #di catalytic 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"w h be5 c>efully *os5 ) ref]5ce to _! usefulness z effective classroom demon/rations4 ,,g9n ,,& ,,company ,,publi%]s ,,app5dix ,a ,,li/ ,,( ,,! ,,elem5ts1 ,,_! ,,symbols1 ,,& ,,atomic ,,weights ,! m important elem5ts are m>k$ ) an a/]isk ,o #af 99,antimony ,sb #abj4b 99,argon ,a #ci4i 99,ars5ic ,z #ge4j 99,b>ium ,ba #acg4d ,b]yllium ,be #i4a 99,bismu? ,bi #bjh4e 99,boron ,b #aa4j 99,brom9e ,br #gi4if 99,cadmium ,cd #aab4d ,csium ,cs #acb4i 99,calcium ,ca #dj4a 99,c>bon ,c #ab4jj ,c]ium ,ce #adj4be 99,*lor9e ,cl #ce4de 99,*romium ,cr #eb4a 99,cobalt ,co #ei4j ,columbium ,cb #id4j 99,copp] ,cu #fc4f ,erbium ,er #aff4j 99,fluor9e ,f #ai4j ,gadol9ium ,gd #aef4j ,gallium ,ga #gj4j ,g]manium ,ge #gb4e 99,gold ,au #aig4b ,helium ,he #d4j 99,hydrog5 ,h #a4jjh ,indium ,9 #aae4j 99,iod9e ,i #abf4ig ,iridium ,ir #aic4j 99,iron ,fe #ee4i ,krypton ,kr #ha4h ,lan?anum ,la #ach4i 99,lead ,pb #bjf4i ,li?ium ,li #g4jc 99,magnesium ,mg #bd4cf 99,manganese ,mn #ee4j 99,m]cury ,hg #bjj4j ,molybd5um ,mo #if4j ,neodymium ,nd #adc4f ,neon ,ne #bj4j 99,nickel ,ni #eh4g 99,nitrog5 ,n #ad4jd ,osmium ,os #aia4j 99,oxyg5 ,o #af4jj ,palladium ,pd #ajf4e 99,phosphorus ,p #ca4j 99,plat9um ,pt #aid4h 99,potassium ,k #ci4ae ,praseodymium ,pr #adj4e ,radium ,ra #bbe4j ,rhodium ,rh #ajc4j ,rubidium ,rb #he4e ,ru!nium ,ru #aja4g ,sam>ium ,sm #aej4c ,sc&ium ,sc #dd4a ,sel5ium ,se #gi4b 99,silicon ,si #bh4d 99,silv] ,ag #ajg4ic 99,sodium ,na #bc4je 99,/rontium ,sr #hg4f 99,sulphur ,s #cb4jf ,tantalum ,ta #ahc4j ,tellurium ,te #abg4f ,t]bium ,tb #afj4j ,?allium ,tl #bjd4a ,?orium ,? #bcb4e ,?ulium ,tm #aga4j 99,t9 ,sn #aai4j ,titanium ,ti #dh4a ,tung/5 ,w #ahd4j ,uranium ,u #bch4e ,vanadium ,v #ea4b ,x5on ,xe #abh4j ,ytt]bium ,yb #agc4j ,yttrium ,yt #hi4j 99,z9c ,zn #fe4d ,zirconium ,zr #ij4f ,,app5dix ,b ,t5sion ( ,aque\s ,vapor express$ 9 ,millimet]s ( ,m]cury ,,temp]ature ,,pressure #af #ac4e #ag #ad4d #ah #ae4c #ai #af4c #bj #ag4d #ba #ah4e #bb #ai4f #bc #bj4i #bd #bb4b #be #bc4e ,weight ( #a ,lit] ( ,v>i\s ,gases measur$ "u ,/&>d ,conditions ,acetyl5e #a4afad ,air #a4bibc ,ammonia #j4gfag ,c>bon dioxide #a4ifda ,c>bon monoxide #a4bdii ,*lor9e #c4afej ,hydrocyanic acid #a4bjcf ,hydro*loric acid #a4fbge ,hydrog5 #j4jhihd ,hydrosulphuric acid #a4ebaa ,me?ane #j4gaeg ,nitric oxide #a4cdaj ,nitrog5 #a4beja ,nitr\s oxide #a4ifgg ,oxyg5 #a4dbhe ,sulphur dioxide #b4heif ,d5sities & ,melt+ ,po9ts ( ,"s ,common ,elem5ts ,,d5sity ,,melt+ ,,po9t ,alum9ium #b4fh #fdj ,antimony #f4gj #dcb ,ars5ic #e4gc -- ,b>ium #c4ge -- ,bismu? #i4hj #bgj ,boron #b4de -- ,cadmium #h4fg #cbj ,csium #a4hh #bf4e ,calcium #a4ed -- ,c>bon1 ,diamond #c4ej -- ,graphite #b4ae -- ,*>coal #a4hj -- ,*romium #g4cj #cjjj ,cobalt #h4ee #ahjj ,copp] #h4hi #ajhd ,gold #ai4cj #ajfd ,iridium #bb4db #aiej ,iron #g4ic #ahjj ,lead #aa4ch #cbg ,li?ium #j4ei #ahf ,magnesium #a4ge #gej ,manganese #h4ja #aijj ,m]cury #ac4eif -#ci4e ,nickel #h4i #afjj ,osmium #bb4dg -- ,palladium #aa4hj #aejj ,phosphorus #a4hj #de ,plat9um #ba4ej #aggi ,potassium #j4hg #fb4e ,rhodium #ab4aj -- ,rubidium #a4eb #ch4e ,ru!nium #ab4bf -- ,silicon #b4ce -- ,silv] #aj4e #ifj ,sodium #j4ig #ig4f ,/rontium #b4ej -- ,sulphur #b4jj #aad4h ,t9 #g4ce #bce ,titanium #c4ej -- ,z9c #g4jj #dbj