4th and 5th Form Qualitative Analysis

Qualitative Analysis Page 1 of 5 Tests involving the reagent aqueous NaOH solution ONLY

TABLE 1. COLOURED SOLUTIONS Ion First addition of reagent Pale geen !"e Dity geen &&t #$ % "e#$ !a'% $ #O( ) !a'%  "e!O(%# !s%

2ello- !"e3

%$Blue !Cu#

%$Big*t geen !C 3

%$Pin7  !Co#

%$Pale &in7 0ut usually +olouless !8n#

%$Rusty 0o-n &&t "e3$ !a'% $ 3O( ) !a'%  "e!O(%3 !s% Pale 0lue &&t Cu#$ !a'% $ #O( ) !a'%  Cu!O(%# !s% Blue o 0lue geen &&t C 3$ !a'% $ 3O( ) !a'%  C!O(%3 !s% Blue &&t -*i+* tuns &in7 on staning Co#$ !a'% $ #O( ) !a'%  Co!O(%# !s% 9*ite o +ea &&t 8n#$ !a'% $#O( ) !a'%  8n!O(%# !s%

TABLE #. COLOURLESS SOLUTIONS Ion First addition of reagent #$ Ca  No &&t $  N(:  No &&t On warming, a colourless pungent pungent  gas is evolved which turns turns red litmus to blue  N !"(a#) " O $ (a#)  N % (g) "   &O(l) #$ 8g 9*ite &&t 8g#$ !a'% $ #O( ) !a'%  8g!O(% # !s% #$ Ba Little o no &&t Al3$

9*ite &&t Al3$ !a'% $ 3O( ) !a'%  Al!O(% 3 !s%


9*ite &&t
P0#$

9*ite &&t P0#$ !a'% $ #O( ) !a'%  P0!O(%# !s%

Reagent in excess  No fut*e +*ange, *o-eve *o-eve at t*e to& of t*e i/tue it ay tun  0o-n on staning staning This is due to oxidation of iron(II) hydroxide to iron(III) hydroxide  No fut*e +*ange

 No fut*e +*ange

P&t issolves foing a 0ig*t geen solution C!O(%3 !s% $ 3O() !a'% 3) 4C!O(%56  !a'%  No fut*e +*ange

Coents Basi+ *yo/ie -*i+* eans it oes not ea+t -it* e/+ess NaO( solution

Basi+ *yo/ie -*i+* eans it oes not ea+t -it* e/+ess NaO( solution Basi+ *yo/ie -*i+* eans it oes not ea+t -it* e/+ess NaO( solution

These ions are not on the C!"C s#lla$us and thus can $e ignored $# %th and 5th for students

 No fut*e +*ange, *o-eve *o-eve &&t ay tun 0o-n on staning This is due to oxidation of Mn(II) hydroxide to Mn(III)oxide

Reagent in excess No &&t  No &&t

Coents

Aonia gas is t*e ONL2 ONL2 al7aline gas you -ill eet at t*is level;

 No fut*e +*ange

No fut*e +*ange Dissolves to fo a +olouless solution Al!O(% 3 !s% $ 3O() !a'% 3) 4Al!O(%56  !a'% Dissolves to fo a +olouless solution
Baiu *yo/ie is vey solu0le *en+e no &&t All t*ee *yo/ies of in+ate, aluinate an &lu0ate es&e+tively.

Qualitative Analysis Page & of 5

Tests involving the reagent aqueous aonia solution

TABLE 3. COLOURED SOLUTIONS Ion First addition of reagent #$ Pale geen !"e % Dity geen &&t "e#$ !a'% $ #O( ) !a'%  "e!O(%# !s%

2ello- !"e3$% Blue !Cu#$% Big*t geen !C 3$% Pin7  !Co#

%$Pale &in7 0ut usually +olouless !8n#

%$Rusty 0o-n &&t "e3$ !a'% $ 3O( ) !a'%  "e!O(%3 !s% Pale 0lue &&t Cu#$ !a'% $ #O( ) !a'%  Cu!O(%# !s% Blue o 0lue geen &&t C 3$ !a'% $ 3O( ) !a'%  C!O(%3 !s% Blue &&t -*i+* tuns &in7 on staning Co#$ !a'% $ #O( ) !a'%  Co!O(%# !s%

9*ite o +ea &&t 8n#$ !a'% $#O() !a'%  8n!O(%# !s%

TABLE :. COLOURLESS SOLUTIONS Ion First addition of reagent #$ Ca  No &&t $  N(:  No &&t #$ 8g 9*ite &&t 8g#$ !a'% $ #O( ) !a'%  8g!O(%# !s% Ba#$ Little o no &&t 3$ Al 9*ite &&t Al3$ !a'% $ 3O() !a'%  Al!O(% 3 !s%
P0#$

9*ite &&t P0#$ !a'% $ #O() !a'%  P0!O(%# !s%

Reagent in excess  No fut*e +*ange, *o-eve at t*e to& of t*e i/tue it ay tun 0o-n on staning This is due to oxidation of iron(II) hydroxide to iron(III) hydroxide  No fut*e +*ange

P&t issolves to give a ee& 0lue solution Cu!O(% # !s% $ :N( 3 !a'%  4Cu!N(3%:6#$ !a'% P&t issolves foing a oyal 0lue solution C!O(% 3 !s% $ 5N(3 !a'% 4C!N(3%563$ !a'% P&t issolves to fo a 0o-n solution -*i+* t*en a7ens on staning Co!O(% # !s% $ 5N(3 !a'% 4Co!N(3%56#$ !a'% The dar'ening is due to the oxidation of o(II) to o(III)  No fut*e +*ange, *o-eve &&t ay tun 0o-n on staning This is due to oxidation of Mn(II) hydroxide to  Mn(III)oxide

Reagent in excess No &&t No &&t  No fut*e +*ange

Coenets

No fut*e +*ange  No fut*e +*ange Dissolves to fo a +olouless solution
A +o&le/ ion o++us in e/+ess aonia solution +alle iaine >in+!II% ion. This reaction distinguishes 'inc ions fro (l)* and +$&* ions

Qualitative Analysis Page ) of 5

T(,L" 5- Tests .ith various reagents other than sodiu h#droxide and aqueous aonia Test O$servation Inference Coents ) Silve nitate solution in 9*ite &&t eans Cl  &esent ilver chloride ppt $ ) t*e &esen+e of ilute  &&t issolves to give a turns from white togrey Ag  !a'% $ Cl  !a'%  AgCl !s% (Cl o (NO 3 +olouless solution in sunlight as the silver T*en follo-e 0y ions are reduced to AgCl !s% $#N( 3 !a'% 4Ag!N(3%#6$ a'ueous aonia  silver which gives the Cea &&t  ppt a grey or even )  &&t &atially issolves  purple colour  B  &esent $ ) Ag  !a'% $ B  !a'%  AgB !s% 2ello- &&t  &&t eains I) &esent

Ag$ !a'% $ I) !a'%  AgI !s% Baiu +*loie o  0aiu nitate solution T*en follo-e 0y ilute (Cl o (NO 3

9*ite &&t

 &&t issolves to give a +olouless solution

 &&t eains Aition of (Cl o any sou+e of +*loie ions  sometimes an additional test may be to warm the mixture if a ppt is  formed and then allow to cool 

Aition of a'ueous  &otassiu ioie solution o aition of P0#$ ions  sometimes an additional test may be to warm the mixture if a ppt is  formed and then allow to cool 

9*ite &&t

SO3#) o SO:#) &esent SO3#) &esent SO3#) !a'% $ #($ !a'%

SO#!g% $

(#O !l%

SO:#) &esent Ba#$!a'% $ SO:#)!a'%  BaSO:%s% P0#$ P0#$ !a'% $ #Cl ) !a'%  P0Cl# !s%

 &&t issolves fully -*en i/tue is -ae an e+ystallises to fo neele s*a&e +ystals -*en +ool

Big*t yello- &&t

P0#$ P0#$ !a'% $ #I ) !a'%  P0I# !s%

Re)0o-n solution -*i+* ay *ave 0la+7 &ati+les.

Potassiu ioie is a eu+ing agent an if a +olou +*ange is seen, t*en a eo/ ea+tion *as o++ue an t*e sa&le *as o/ii>ing &o&eties.

Dilute niti+ o *yo+*loi+ a+i ust  0e &esent to &event t*e &e+i&itation of +a0onates.

lea!II% +*loie is oe solu0le in *ot -ate t*an +ol -ate. T*eefoe one -oul see a total eu+tion in t*e aount of &&t  &esent -*en i/tue is -ae. As it +ools, +ystalli>ation o++us an t*e tue s*a&e of t*e +ystals ae seen. N, lead/II0 $roide gives a siilar o$servation $ut it is onl# artiall# solu$le in hot .ater .hile lead/II0 chloride is coletel# solu$le in hot .ater lea!II% ioie is oe solu0le in *ot -ate t*an +ol -ate. A  &atial eu+tion in t*e aount of &&t &esent -*en i/tue is -ae -oul 0e seen. As it +ools, +ystalli>ation o++us an t*e tue s*a&e of t*e +ystals ae seen. Often t*e +ystals

Qualitative Analysis Page % of 5 e/*i0it a ?glittey@ effe+t. Con+. sul&*ui+ a+i to a soli *alie e.g. soiu +*loie, soiu 0oie, soiu ioie

igouous effeves+en+e -*ite i/tue Colouless, &ungent gas Tuns 0lue litus e

Cl) &esent as is a+ii+ as is *yogen +*loie is&la+eent of *yogen +*loie 0y sul&*ui+ a+i  NaCl $ (#SO:  (Cl $ Na(SO :

igouous effeves+en+e oangee i/tue  0o-n, &ungent gas Tuns 0lue litus e t*en -*ite

B ) &esent Boie ions ae stong eu+ing agents an a eo/ ea+tion o++us an 0oine is &ou+e gas is a+ii+ an it also 0lea+*es -*i+* i&lies t*e *alogen is 0eing &ou+e (#SO: $ #($ $ #B )  B # $ SO# $ #(#O

igouous effeves+en+e ee& &u&le0la+7 i/tue  &u&le, &ungent gas Tuns 0lue litus e t*en -*ite

Aition of a+iifie  &otassiu anganate solution Aition of a+iifie  &otassiu i+*oate solution Aition of ilute a+i to a soli sa&le eit*e ilute (Cl o (NO 3

De+olouisation i.e. fo  &u&le to +olouless oes fo oange to geen

Effeves+en+e Soli issolves  No effeves+en+e Soli issolves

Aition of Devaas alloy to sa&le in &esen+e of NaO( solution an -a

Effeves+en+e Colouless, &ungent gas evolve tuns e litus 0lue

Aition of +on+ ( #SO: -it* +o&&e tunings  &esent an -a

Effeves+en+e Blue)geen solution Bo-n, &ungent gas evolve Tuns 0lue litus e

Aition of fes*ly  &e&ae ion!II% sul&*ate solution o +ystals an t*en a +on+ (#SO: slo-ly

Bo-n ing is foe

Con+entate sul&*ui+ a+i is a  &o-eful o/ii>ing agent

I) &esent Ioie ions ae stong eu+ing agents an a eo/ ea+tion o++us an ioine is  &ou+e gas is a+ii+ an it also 0lea+*es -*i+* i&lies t*e *alogen is 0eing &ou+e  (#SO: $ ($ $ I)  :I# $ (#S $ :( #O Sin+e a+iifie &otassiu anganate is an o/ii>ing agent, t*e sa&le teste ust *ave eu+ing &o&eties Sin+e a+iifie &otassiu i+*oate is an o/ii>ing agent, t*e sa&le teste ust *ave eu+ing &o&eties as &ou+e sa&le ust 0e eit*e a +a0onate o a sul&*ite Sa&le ust 0e eit*e an o/ie o *yo/ie as is 0asi+ as is aonia  NO3) ion &esent 3NO3) $ Al $ FO( G $ 1(#O H 3N(3 $ 4Al!O(% :6G as is a+ii+  NO# gas &ou+e !0o-n gas%  NO3) ion &esent 3Cu!s% $ (NO3!a'% )) 3Cu!NO3%#!a'% $ #NO!g% $ :(#O!l%

NO3) &esent  NO3) $ 3"e#$ $ :($ H 3"e3$ $ NO $ #(#O 4"e!(#O%56#$ $ NO H 4"e!(#O%F!NO%6#$ !0o-n ing%

T*e +on+ sul&*ui+ a+i ea+ts -it* t*e nitate ion to fo niti+ a+i. T*e niti+ a+i t*en ea+ts -it* t*e +o&&e tuning to fo nitogen ono/ie -*i+* is o/ii>e to nitogen io/ie T*e 0o-n ing is not al-ays easily seen, it is a +onfiation test t*at t*e nitate ion is &esent

Qualitative Analysis Page 5 of 5 Aition of &otassiu 8usta !0o-n% li'ui ioie solution follo-e 0y 9*ite &&t !+olou as7e 0y a'ueous soiu  0o-n li'ui% t*iosul&*ate solution until no fut*e +*ange 9*en t*iosul&*ate solution ae t*e &&t issolves an solution tuns +olouless

Aition of &otassiu *e/a+yanofeate!II%

Dee& 0lue &&t !Pussian 0lue%

Aition of &otassiu t*io+yanate o aoniu t*io+yanate Aition of &otassiu *e/a+yanofeate!III%

Bloo e solution

Dee& 0lue &&t !Pussian 0lue%

Cu#$ ion &esent 9*ite &&t is +o&&e !I% ioie. T*e +o&&e!II% ion is eu+e to +o&&e!I% an soe ioie ions o/ii>e to ioine. #Cu#$!a'% $ :I)!a'%  #CuI!s% $ I#!a'% T*e t*iosul&*ate t*en ea+ts -it* t*e ioine ole+ules to fo +olouless ioie ions. #S#O3#)!a'% $ I# !a'% S:O5#)!a'% $ #I)!a'% "e3$ ions &esent :"e3$!a'% $ 3"e!CN% 5:)!a'% "e:4"e!CN% 563 !s% "e3$ ions &esent "e3$!a'% $ SCN)!a'%  "e!SCN% #$!a'% "e#$ ions &esent 3"e#$!a'% $ #"e!CN% 53)!a'% "e34"e!CN% 56# !s%

T(,L" 2- Tests involving gases 3as CO#

Test Bu00le gas into lie.ater test gas -it* oist e an 0lue litus

O$servation with inference in italics 9*ite &&t foe ! formation of insoluble calcium carbonate ) a(O) & " O&  aO% "  &O)

solution goes +olouless on e/+essive 0u00ling of gas (calcium carbonate reacts with more carbon dioxide to form soluble calcium hydrogencarbonate aO% " O& "  &O  a(O % )&

(#

Pla+e a lighted s&lint in t*e gas test gas -it* oist e an 0lue litus

O#

Pla+e a glo.ing s&lint in t*e gas test gas -it* oist e an 0lue litus test gas -it* oist e an 0lue litus  &la+e glass o i&&e in +on+. (Cl in t*e gas

 N(3

SO#

Bu00le gas into a+iifie &otassiu anganate o i+*oate

(Cl

&la+e glass o i&&e in +on+. aonia in t*e gas

Cl#

Test -it* oist litus

B #

Test -it* oist litus

I#

Test -it* oist litus

 NO#

Test -it* oist litus

a+ii+ gas ! forms carbonic acid O& "  &O   &O% ) E/tinguis*es a lig*te s&lint -it* a ?&o&@ soun ! hydrogen combusts with oxygen) Colouless gas -it* no effe+t on litus ! neutral gas) Re7inles a glo-ing s&lint (oxygen supports combustion) Colouless gas -it* no effe+t on litus ! neutral gas) Tuns e litus 0lue !basic gas) "os ense -*ite fues (reacts with hydrogen chloride gas to  form small particles of ammonium chloride  N %(g) " l (g)  N !l (s) Colouless gas -it* +*o+7ing sell Pu&le to +olouless !a+iifie &otassiu anganate% o oange to geen !a+iifie &otassiu i+*oate% ! gas has reducing properties) Dense -*ite fues (reacts with ammonia gas to form small  particles of ammonium chloride N %(g) " l (g)  N !l (s) &ale yello-)geen gas -it* +*o7ing sell  0lea+*es litus (forms hypochlorous acid which has bleaching  properties) Bo-n gas -*i+* 0lea+*es litus (forms hypobromous acid which has bleaching properties) Dee& &u&le gas -*i+* 0lea+*es litus (forms hypoiodous acid which has bleaching properties) Bo-n gas -it* +*o7ing sell Tuns 0lue litus e (forms nitric acid when in contact with water)