CHEMI STRY

EXERCISE-I
Q.1 Asolution ofwhite solid (A) gave white precipitate (B) with water. On treatment with HCl, the ppt.B
producedA. The solution ofAgives black precipitate (C) on reacting with sodiumstanite and NaOH.
The compoundAgives a colourless gas (D) with concentrated H2SO4. Thegas is soluble inwater and
its aqueous solution produce with it precipitate with Hg2(NO3)2 but no precipitate with Hg(NO3)2.
Identify(A) to (D) and write thechemicalreactions involved.
Q.2 A solution ofwhite solid (A) insoluble in water and soluble in conc. HClon exposure to air gradually
turns green. The compound(A) also dissolvesinNH3 to give a colourlesssolution. But onkeepinginair
the solutionturns dark blue. Theammonicalsolutionofcompound(A) forms a redexplosive compound
withacetylene. Identify, (A) and explainthe reactions.
Q.3 Anaqueous solutionofa gas (X) gives the following reactions.
(i) It decolourises an acidified K2Cr2O7 solution.
(ii) Onboiling withH2O2, coolingit and thenadding anaqueous solutionofBaCl2, aprecipitate insoluble in
dil. HClis obtained.
(iii) OnpassingH2Sinthesolutionswhiteturbidityisobtained.IdenfityXandgiveequationsforsteps(i),(ii)&(iii).
Q.4 Awellknownorange crystalline compound(A). Whenburnt impartsviolet colour to flamewhenheated
with compound (B) in presence of concentrated H2SO4 it evolves a red gas C which when passed
through alkaline solutionoflead acetate gives yellow precipitate of(D). Compound (B) sublimes on
heating when Bis heated with NaOH, it evolves gas E whichfumes with HCl. IdentifyAto E.
Q.5 Awhitecoloured inorganic salt givesfollowing reactions.
(i) When exposed to H2S becomes black
(ii) It isdecomposed bydilHClevolving a gas witheffervescence, the gas turnslime water milky
(iii) When heated strongly to about 450° it decomposes to give three gases and leaves a red coloured
residue used byhousewives. Identifycompound Xand the four gases evolved during reactions.
Q.6 Acompound Xdoes not give N2 onheating. Its aqueous solutionwhenheated withcausticsoda liberate
a gasYwhich turns red litmus blue. Heating ofalkaline solution ofX is continued to expellthe gasY
completely. However residualsolutionagainliberates thegasYwhenheatedwithZinc powder. Identify
X andY.
Q.7 Identifythe inorganicsaltAWhose aqueous solutiongives following reactions.
(i) PaleYellow precipitate withAgNO3 solution, insoluble indilHNO3
(ii) Whiteprecipitate withNH4OH andalso withNaOHsolution. Howeverthe precipitate doesnot dissolve
in excess ofNH4OH but soluble inexcess of NaOH.
Q.8 A certain compound (X) is used in laboratory for analysis. Its aqueous solution gives the following
reactions.
(i) Onadditionto a copper sulphatesolution, a brownprecipitateis obtained whichturns white onaddition
of excess of Na2S2O3.
(ii) On additionofAg+ ionsolutionaYellowcurdyprecipitate is obtained whichis insolubleinNH4OH.
(iii) Identify(X) and give reactions at step (i) and (ii).
Q.9 Anaqueous solutionofaninorganiccompound (X) gives thefollowing reactions.
(i) Withan aqueous solution ofbariumchloride a precipitate insoluble indilute HClis obtained.
(ii) Addition ofKI gives a brownppt. which turns white, on addition ofexcess ofhypo.
(iii) Withan aqueoussolutionofK4 [Fe(CN)6];a chocolatecoloured precipitate is obtained. IdentifyX and
give equationfor (i), (ii) and(iii) observations.

Q.10 Ablackcolouredcompound(A)onreactionwithdilH2SO4 givesagas(B)whichonpassing inasolution
ofanacid(C)gives awhite turbidity(D). Gas(B) whenpassed inanacidifiedsolutionofa compound (E)
givesa precipitate(F)soluble indilHNO3.After boilingthis solutionwhenanexcessofNH4OHisadded,
a blue colouredcompound (G) is formed.To this solutiononadditionofacetic acidand aq K4[Fe(CN)6]
a chocolate coloured precipitate (H) is obtained. On addition ofanaqueoussolution ofBaCl2 to anaq.
solutionofE awhite precipitateinsoluble inHNO3 isobtained. Identify(A)to (H).
Q.11 Ametalchloride (X) shows thefollowing reactions:
(i) When H2S is passed in acidified aqueous solutionof (X) a black ppt. is obtained.
(ii) The ppt. obtained in step (i)is not soluble inyellow ammoniumsulphide.
(iii) When a solution of stannous chloride is added to an aqueous solution of X, a white ppt. is obtained
whichturns greyonadditionofmore stannous chloride.
(iv) When anaqueous solution of KI is added to an aqueous solution of (X) a red ppt. is obtained which
dissolved on additionofexcess ofKI. IdentifyX and write downequations for the reactions at step(i),
(ii), (iii)&(iv).
Q.12 Anunknowninorganiccompound(X)losesits waterofcrystallisationonheating anditsaqueoussolution
gives thefollowing tests.
(i) It gives whiteturbiditywithdilHCl
(ii) It decolourises a solution ofiodine in KI
(iii) It givesawhite ppt withAgNO3 solutionwhichturns black onstanding. Identifycompound (X)and give
chemicalequationforthe reactionat step (i), (ii) & (iii).
Q.13 Aninorganic sodiumsalt (A) gives two colourless gases (B) and (C)leaving a residue (D). B turns white
copper sulphate blue, while C turns lime water milkyand then colourless. The residualsolid (D) when
heated stronglygives substance (E) and (F). E gives whiteprecipitate with BaCl2. Fwhen treated with
dil. HClgives agas (G), which when passed througha solutionofSO2 givesa yellow precipitatedue to
(H). IdentifyAto H withproper reasoning.
Q.14 Awhite compound(A) whenheated withdil. HClgave onoffensivesmelling gas (B) anda solution(C).
The residualsolution (C) did not give any precipitate with NH4OH but a definite precipitate (D) was
obtained withNaOH which however dissolves in excess ofreagent. (A) When heated stronglyin air
gave another offensive smelling gas (E) and a solid (F). Fdissolved completelyin HCland gave white
precipitate withBaCl2. Identify(A) to (F) andexplain the reaction.
Q.15 An aqueoussolutionofsalt (A)gives a white crystalline precipitate (B) with NaClsolution. The filtrate
gives a black precipitate (C) when H2S is passed into it. Compound (B) dissolves in hot water and the
solution gives yellow precipitate (D) on treatment withsodiumiodide and cooling. The compound (A)
doesnot giveanygaswithdiluteHClbut liberatesareddishbrowngasonheating.Identifythecompounds
(A) to (D)and give an equationfor the liberationofthe reddishbrown gas.
Q.16 A mixture oftwo salts weretreated as follows
(i) The mixture was heated with MnO2 &conc H2SO4.Ayellowish green gas was liberated.
(ii) The mixture onheating with NaOH solutiongave a gas, whichturnedred litmus blue.
(iii) The solutionin water gave brown colouration with K3Fe(CN)6 and red colourationwith NH4CNS.
(iv) The mixture was boiled with KOH and the liberated gas was bubbled through analkaline solution of
K2HgI4 to give brownprecipitate. Identifythe two salts. Give ionic equations for reactions involved in
the test (i), (ii) & (iii).
Q.17 Acolourlesswatersoluble solid X onheating gives equimolar quantities ofYand Z.Ygives dense white
fumes withHCland Z does so withNH3. Ygives brown precipitatewith Nessler’s reagent andZ gives
white precipitate withnitrates ofAg+, Pb2+and Hg+. What is X?

EXERCISE-II
Q.1 Theaqueoussolutionofainorganiccompound(X)yieldedawhiteprecipitatewhentreatedwithdilHNO3
andAgNO3.Anothersampleofthesolutionof(X) whentreatedwithNaOHgave awhite precipitatefirst
whichdissolved inexcess ofNaOH yielding acolorlesssolution. WhenH2S gaswas passedthroughthat
solutionawhiteprecipitatewasobtained. Identifythecompound (X) andgivethereactions.
Q.2 Agreencompound (A) gives blackresidue (B) onreactingwithammoniumsulphide whichis soluble in
aqua regia. Its solution in aqua regia againgives compound (A). This solution ontreatment withKCN
and the resulting solution on treatment with NaOH and Br2 water followed by heating gives a black
residue. Identifythe compounds (A), (B) and (C) and explainthe reactions involved.
Q.3 Acolorless crystalline solid (A) turns our skin black. It gives two gases (B) and (C) onheating (950°C)
along with a residue (D). The gas (B) is soluble in water to give a compound (E). The residue (D) is
soluble in (E). The solid (A) gives white precipitate with NaOH which produces silver mirror with
glucose solution. The solid (A) also gives white precipitate with KCN which is soluble in excess of
KCN. Identifythe compound (A).
Q.4 Acompound (X) onheating withanexcess ofNaOH solution givesa gas (Y) whichgives white fumes
on exposure to HCl. Heating is continued to expelthe gas completely. The resultant alkaline solution
again liberatesthe same gasYwhenheated with Znpowder. However, the compound(X) whenheated
alone does not give nitrogen. Identifythe compoundsX andY.
Q.5 An orange coloured solid (A) is soluble in water and gives a gas (B) and green coloured solid (C) on
heating. The compound (A) gives a gas(D) when reacts withNaOH and solution turns yellow. The gas
(D) turns red litmus blue. Identifythe compounds (A) to (D) and explain the reaction.
Q.6 An inorganic compound (A), transparent like glass is a strong reducing agent. Its hydrolysis in water
gives awhite turbidity(B).Aqueoussolutionof(A) gives white precipitate (C) withNaOH (aq.) which
is soluble in excess NaOH. (A) reduces cupric chloride to produce purple ofcassius. (A) also reduces
I2 and giveschromylchloride test.
Q.7 Anunknowninorganic compound (A) gavethe following reactions.
(i) The compound (A) on heating gave a residue, oxygenand anoxide ofnitrogen.
(ii) An aqueous solution of the compound (A) on addition of tap water gave a turbidity which did not
dissolve innitric acid.
(iii) The turbiditydissolved in NH4OHsolution.
Q.8 A white compound (A), on heating with an excess ofdilHCl gave anoffensive smelling gas (B) and a
solution(C). Solution(C)ontreatment withaqueous NH3 didnot give Cl2 &precipitatebutontreatment
with NaOH solution gave a precipitate. (D) which dissolved inexcess ofNaOH. (A) on strong heating
in air gave a strong smelling gas (E) and a solid residue (F). F dissolves completely in dilHCl andthe
solutiongave aprecipitate with BaCl2 inacid solution. Identify(A) to (F).
Q.9 Amixture oftwo white substances issoluble in water. Thissolutiongives brown colour gas onpassing
chlorinegas.AnothersampleofsolutiongiveswhiteprecipitatewithBaCl2 whichissolubleinconcentrated
HCl. The originalsolution ofthe mixture gives white precipitate with large excess ofNaOH solution
whose suspensionis used as anantacid. After filtering offthis precipitate, the filtrate was boiled with
excess NaOH. This solution gave a yellowish precipitate on adding NaClO4. Identifythe mixture.
Q.10 An aqueous solutionofsalt (A) gives white crystalline precipitate. (B) with NaClsolution. The filtrate
gives a black precipitate. (C) when H2S is passed in it. Compound (B) is dissolved in hot water and the
solutiongives ayellow ppt. (D) ontreating withNaI and cooling. The compound (A) does not give any
gas withdilHClbut liberated reddishbrowngas onheating. Identifythe compound (A), (B), (C) &(D).

Q.11 An aqueous solution ofacompound (X) when treated with BaCl2 solutiongives a white precipitate in
soluble inconcentrated HCl.Another sample of (X) gives first white precipitate with NaOH which is
soluble in excess ofNaOH solution. The solution of(X) does not give the precipitate on passing H2S
gas. Identifythe compound (X) andgive necessaryreactions.
Q.12 Apale yellowinorganiccompound (A)is insolubleinmineralacid but is solubleinaqueousNH3 forming
(B). It also dissolves in Na2S2O3 solution and forms (C). Onboiling anaqueous solutionof(C), a black
precipitate (D) is obtained. When(D) isdissolved inHNO3 andHClis added, awhite precipitate.(E) is
obtained. (A) onheating withconcentrated H2SO4 and MnO2 yieldsbrownfumes. Identify(A)to (E).
Q.13 A unknown inorganic compound (X) gave the following reactions : (i) on heating ‘X’ gave a residue ,
oxygenandoxideofnitrogen. (ii)AdditionofaceticacidandK2Cr2O7 toitsaqueoussolutiongiveayellow
precipitate. (iii)AdditionofNaOH to its aqueous solutionfirst forms a white precipitate, dissolve in the
excess ofthereagent. Identifythecompound(X) andwrite balancedequationfor step (i), (ii) &(iii).
Q.14 Ametallicchloride (A)doesnot respond to chromylchloridetest. However(A) givesawhite precipitate
with limited amount ofanother metalchloride (B) and greyprecipitate withexcess amount of(B). (A)
whentreated withKI gives ascarlet redprecipitatewhichdissolvesinexcess ofKIforming animportant
reagent (C) used in qualitative analysis. Identify(A), (B) and (C). Write allreactions.
Q.15 Compound (A) is greenish solid which gives the following tests: (i)Addition of BaCl2 solution to a
solutionof(A) results intheformation ofa whiteprecipitate (B) whichis insoluble indilute HCl. (ii) On
heating water vapours and two oxides of sulphur(C) & (D) are liberated, leaving a red brown residue
(E). (iii) Compound(E) dissolves inwarmconcentrated HClto givea yellow solution(F). (iv)WithH2S
gas, the solution(F) yields a yellow white precipitate. (G) which when filtered leaves a greenish filtrate
(H). Identifythe compoundsAto H.
Q.16 Asolution ofwhite solid (A) gave white precipitate (B) with water. On treatment with HCl, the ppt.B
producedA. The solution ofAgives black precipitate (C) on reacting with sodiumstanite and NaOH.
The compoundAgives a colourless gas (D) with concentrated H2SO4. Thegas is soluble inwater and
its aqueous solution produce with it precipitate with Hg2(NO3)2 but no precipitate with Hg(NO3)2.
Identify(A) to (D) and write thechemicalreactions involved.
Q.17 Awhitesolid (A) loses onheating one sixthofits weight and becomesa yellow solid (B), (B) onheating
inair gainsweight &gives a red solid (C). (C) is partlysolubleindilHNO3 leaving a brownresidue (D).
(A) is solubleindilHNO3 givingeffervescenceto give a solution(E). (E) reacts withNaOH followed by
Cl2 water to give (D). (A) does not appreciablydissolves in dilHCl or H2SO4. Identify(A) to (E).
Q.18 Awhitesubstance(A)onheatingwithexcessofdilHClgaveanoffensivesmellinggas (B) andasolution
(C). Solution (C) on treatment with aqueous NH3 did not give anyprecipitate but on treatment with
NaOH solution gave a precipitate (D) which dissolves in excess of NaOH solution. (A) on strong
heating inairgave astrongsmelling gas (E)andasolid(F). Solid(F) dissolved completelyinHClandthe
solutiongave aprecipitate withBaCl2, inacid solution. IdentifyAto Fand writethe chemicalequations
for variousreactions involved.
Q.19 (A) Gives a blue solutionin H2O. Onpassing H2S, a black precipitate (B) is formed which is soluble in
HNO3. Onaddition ofNaOH, thesolutiongives blue precipitate(C) whichbecomes black onboiling in
NaOH. On passing ammonia into solution of (A) in water, a deep blue precipitate is formed, which
dissolves inexcess ofNH3 giving deep blue colouration (D). Treatment ofKCN withaqueous solution
of(A) gives a yellow ppt. (E) which dissolves inexcess ofKCN giving a colourless solution.
Q.20 An unknown solid mixture contain one or two of the followings :CaCO3, BaCl2, AgNO3, Na2SO4,
ZnSO4 and NaOH. The mixture is with phenolphthalein. When dilHCl acid is graduallyadded to the
abovesolution,a precipitate isformedwhichdissolveswithfurtheradditionoftheacid.Givecomposition
ofmixture&equations.

Q.21 An aqueoussolutionofsalt (A)gives a white crystalline precipitate (B) with NaClsolution. The filtrate
gives a black precipitate (C) when H2S gas is passed into it. Compound (B) is precipitate(D) withNaI
solution and cooling. The compound (A) does not give any gas with dil HCl but liberates a reddish
brown gas on heating. IdentifythecompoundsA, B, C andD. Write the chemicalequations for various
reactionsinvolved.
Q.22 Three black powderA, B, C are kept in three dishes. Adissolves in dil H2SO4 to give blue solution.
Moistened withHCl,Agives agreencolour inflame test. B does not dissolve indilHClbut whenboiled
withconcentratedHCl, dissolvesgivingchlorine. ThissolutionwithH2Sinammonicalsolutionproduces
a flesh coloured precipitate C does not dissolve in HCl but when heated with KNO3, burns away
evolving a gas which lime water milky. What areA, B & C?
Q.23 A salt reacts with NaOH to forma green colouredppt. (X) which is soluble in excess ofNaOH. (X) on
heating gives agreen powder (Y). (Y) onfusion withNaOH inair gives a yellow coloured solution (Z).
Identifythe compoundX,Y& Z.
Q.24 When a whitepowder (A) is stronglyheated, it gives offa colourless, odorless gas (B)which turnslime
water milky(C) and ifandgives a solution(D). The solid residue (E)is yellow whenhot but turnswhite
on cooling. Identifythe compoundsA, B, C, D and E. Write the chemicalequationfor the reactions.
EXERCISE-III
(Asked in REE) :
Q.1 Anunknowninorganic compound (X) gavethe following reactions.
(i) The compound(X) onheating gave a residue, oxygenand oxide ofnitrogen.
(ii) An aqueous solutionofcompound (X) onadditionto tap water gave a turbiditywhichdid not dissolve
in HNO3.
(iii) The turbiditydissolved inNH4OH.
Identifythe compound (X) and give equations for the reactions (i), (ii) &(iii).
Q.2 An unknown inorganic compound (X) loses its water of crystallisation. On heating and its aqueous
solutiongivesthefollowingreactions:
(i) It givesa white turbiditywithdiluteHClsolution.
(ii) It decolourisesa solution ofiodineinKI.
(iii) It gives awhite precipitate withAgNO3 solution whichturns black on standing.
Identifycompound (X) and give chemicalequations for the reactionsat step (i), (ii) &(iii).]
Q.3 Acertaininorganic compound (A)onheating loses water ofcrystallisation. Onfurtherheatinga blackish
brown powder (B) and two oxides ofsulphur (C & D) are obtained. The powder (B) on boiling with
HCl gives a yellow solution (E). When H2S is passed in (E) a white turbidity(F) and an apple green
solution(G)is obtained. The solution(E) ontreatment withthiocyanate iongives bloodred compound
(H). Identify(A) to (H).
Q.4 Identify(A), (B), (C) &(D) and givetheir chemicalformulae:
(i) (A) + NaOH 
 

heat
NaCl + NH3 + H2O
(ii) NH3 + CO2 + H2O  (B)
(iii) (B) + NaCl  (C) + NH4Cl
(iv) (C) 
 

heat
Na2CO3 + H2O + (D)

Q.5 A black coloured compound (A) on reaction with dilute H2SO4 gives a gas (B) which on passing in a
solution of an acid (C) gives a white turbidity (D). Gas (B) when passed in an acidified solution ofa
compound (E) givesa precipitate (F) solubleindilHNO3.Afterboiling this solution whenan excess of
NH4OHisadded,a blue colouredcompound(G) is formed. To thissolutiononadditionofacetic acid and
aqueous K4[Fe(CN)6] a chocolate precipitate (H) is obtained. On addition of an aqueous solution of
BaCl2 to anaqueoussolutionof(E), awhiteprecipitate insolubleinHNO3 isobtained. Identify(A)to (H).
Q.6 Onthe basisoffollowingreaction, Identify(A), (B), (C) &(D) and write downtheir chemicalformulae?
(i) (A) aqueous + Zn 
 

heat
(B)gas
(ii) (A) aqueous + (C) 
 

heat
PH3
(iii) (A) aqueous + NH4Cl 
 

heat
(D) gas.
Q.7 Anaqueoussolution ofanunknowncompound (X) gives thefollowing reactions.
(i) It gives brownprecipitate withalkaline KMnO4 solution.
(ii) It forms HCl& evolved O2 when reacts with Cl2 gas.
(iii) It liberates I2 fromanacidified KI solution.
(iv) It gives orangeyellow colour withacidifiedtitanic sulphate solution.
Identify(X) andgive the chemicalequationsfor the reactions (i), (ii) &(iii).
Q.8 Anaqueoussolutionofinorganic compound (X)gives following reactions.
(i) With anaqueous solution ofBaCl2 a precipitate insoluble in dilute HClis obtained.
(ii) addition ofexcess ofKI gives abrown precipitate which turns white on addition ofexcess ofhypo.
(iii) With an aqueous solution ofK4Fe(CN)6 a chocolate coloured precipitate is obtained.
Identify(X) andgive equations for thereactionfor (i), (ii) &(iii) observations.
Q.9 An inorganic compound (X) gives brick red flame on performing the flame test. This also give the
followingtests:
(i) Smellofchlorine when placed inmoist air.
(ii) IfKI & CH3COOH are added to its suspension in water, a brown colour is obtained. Identify(X) and
write down equations for reactions at step (i) & (ii).
Q.10 Acompound (X) imparts a goldenyellow flame and shows the following reactions:
(i) Zn powder whenboiled with aconc. aqueous solutionof(X) dissolves and hydrogen is evolved.
(ii) Whenanaqueoussolutionof(X)isadded to anaqueoussolutionofstannous chloride,a whiteprecipitate
is obtained first which dissolves inexcess ofsolutionof(X).
Identify(X) and write equations at step (i) & (ii).
Q.11 Acertain metal(A)is boiled indilute HNO3 to give a salt (B) and an oxideofnitrogen(C).Anaqueous
solutionof(B)withbrinegives aprecipitate(D)whichissolubleinNH4OH. Onaddingaqueous solution
of(B)to hypo solution, awhiteprecipitate(E)isobtained. (E)turnsblackonstanding. Identify(A)to (E).
Q.12 Anaqueous solutionofa gas (X) givesthe following reactions:
(i) It decolourises an acidified K2Cr2O7 solution.
(ii) Onboiling it withH2O2, coolingit &thenadding anaqueous solutionofBaCl2 aprecipitate insoluble in
dilute HClis obtained.
(iii) On passing H2S inthe solution a whiteturbidityis obtained.
Identify(X) and give equations for thereactions at step (i), (ii) & (iii).
Q.13 Ametalchloride (X) shows thefollowing reactions:
(i) When H2S is passed in an acidified aqueous solutionof(X) a black ppt is obtained.

(ii) The precipitateobtained instep (i)is not soluble inyellow ammoniumsulphide.
(iii) When a solution of stannous chloride is added to an aqueous solution of (X), a white precipitate is
obtained whichturnsgreyonadditionofmore ofstannous chloride.
(iv) When an aqueous solution ofKI is added to an aqueous solution of (X), a red precipitate is obtained
which dissolves on addition ofexcess ofKI.
Identify(X)and write down theequations for the reactions at steps (i), (iii) & (iv).
Q.14 An aqueous solutionofa gas (X) shows the following reactions.
(i) It turnsred litmus blue.
(ii) When added inexcess to a CuSO4 solution, a deep blue colour is obtained.
(iii) On addition ofFeCl3 solutiona brown precipitate soluble indilute HNO3 is obtained.
Identify(X) and give equations for the reactions at step (ii) & (iii).
Q.15 A certain compound (X) is used in laboratory for analysis. Its aqueous solution gave the following
reactions.
(i) Onadditionto CuSO4 solution, a brown precipitateis obtained which turnswhite on additionofexcess
ofNa2S2O3 solution.
(ii) On additiontoAg+ ionsolution a yellow curdyprecipitate is obtained which is insolubleinNH4OH.
Identify(X)ingivenreactions.
Q.16 Acertainsalt (X) gives thefollowing tests:
(i) Its aqueous solutionis alkaline to litmus.
(ii) Onstronglyheating it swells to give glassymaterial.
(iii) When conc. H2SO4 is added to a hot conc. solution of(X), white crystals of weak acid separate out.
Identify(X) and write downthechemicalequationfor reactionsat steps (i), (ii) & (iii).
Q.17 Acertaincompound (X) shows thefollowing reactions:
(i) When KI is added to anaqueous suspension of(X) containing acetic acid, iodine is liberated.
(ii) When CO2 is passesthroughan aqueous suspensionof(X) the turbiditytransforms to a precipitate.
(iii) When a paste of(X) in water is heated with ethylalcohol, a product ofanaesthetic use is obtained.
Identify(X) and write down chemicalequations for reactionat step (i), (ii) & (iii).
Q.18 Anaqueoussolutionofaninorganiccompound (X) shows thefollowing reactions:
(i) It decolourizes anacidified KMnO4 solutionaccompanied withevolutionofoxygen.
(ii) It liberates I2 fromacidified KI solution.
(iii) It gives brownprecipitate withalkaline KMnO4 solutionwithevolutionofO2.
(iv) It removeblack stains fromold oilpainting.
Identify(X)and give chemicalreactionsfor the steps (i) & (iv).
Q.19 Two solid laboratoryreagents (A) &(B)give following reactions:
Compound (A) :
(i) Onstronglyheating it gives two oxides ofsulphur.
(ii) On adding aqueous NaOH solution to its aqueous solution, a dirtygreen precipitate isobtained which
starts turning brownon exposure to air.
Compound (B) :
(i) It imparts greencolour to flame.
(ii) Its solutiondoesn’t give precipitate onpassing H2S
(iii) When it is heated with K2Cr2O7 &conc. H2SO4, ared gas is evolved. The gas whenpassedinaqueous
NaOH solutionturns it yellow.
Identify(A)to (B) and give chemicalreactions.
Q.20 Identify(A) to (D) infollowing steps andgive chemicalequations.
(i) Awhite amorphous powder (A) onheating yields a colorless, non-combustible gas (B) and a solid (C).

(ii) The gas (B)turns lime water milkybut the milkiness disappearswiththe continuous passageofthe gas.
(iii) Compound (C) dissolves indilute acid gives a white precipitate on additionofK4[Fe(CN)6] solution.
(iv) The solutionof(A) gives a white precipitate (D) onthe addition ofexcessofNH4OH andpassing H2S.
Q.21(i) A black mineral(A) on heating inpresence ofair gives a gas (B).
(ii) The mineral(A) onreaction with dil. H2SO4 gives a gas (C) &solutionofa compound (D).
(iii) On passing gas(C) into anaqueoussolutionof(B) a white turbidityis obtained.
(iv) The aqueous solutionofcompound (D) onreactionwithpotassiumferricyanide givesa blue compound
(E). Identify(A) to (E) and give chemicalequations for reactions at steps (i) to (iv).
Q.22 Aninorganic lewis acid (X) showsthe following reactions.
(i) It fumesin moist air.
(ii) The intensityoffumes increases when a rod dipped in NH4OH is brought near it.
(iii) Anacidic solutionof(X) on additionofNH4Cl& NH4OH givesa precipitate whichdissolvesin NaOH
solution.
(iv) An acidic solutionof(X) does not giveprecipitate with H2S.
Identify(X) and give chemicalequations.
Q.23 The certaininorganic compound (X) showsthe following reactions:
(i) On passing H2S throughanacidified solution of(X) a brown precipitateis obtained.
(ii) The precipitate obtained at step (i) dissolves inexcess ofyellow ammoniumsulphide.
(iii) Onaddingan aqueous solutionofNaOH to a solutionof(X) , first a white precipitate isobtained which
dissolves in excess ofNaOH.
(iv) The aqueous solutionof(X) reduces FeCl3.
Identify(X) cationand give chemicalequations.
Q.24(i) Aninorganiciodide(A)onheatingwithasolutionofKOHgivesagas(B)andthesolutionofacompound(C).
(ii) The gas(B) on ignitioninair gives a compound (D) and water.
(iii) CuSO4 is finallyreduced to the metalonpassing (B) through its solution.
(iv) A precipitate of compound (E) is formed on reaction of (C) with CuSO4 solution. Identify(A) to (E)
and givechemicalequation.
Q.25(i) Aninorganic compound(A) is formed onpassing a gas (B) througha conc. liquor containing Na2Sand
sodiumsulphite.
(ii) On adding (A) into a dilute solutionofsilver nitratea white precipitate appears which quicklychanges
into a black coloured compound (C).
(iii) On adding two or three drops ofFeCl3 into the excess ofsolution(A) a violet colouredcompound (D)
is formed. This colour disappears quickly.
(iv) Onadding asolution of(A) into the solution ofcupric chloride, a white precipitate isfirst formed which
dissolves onadding excess of(A) forminga compound (E).
Identify(A)to (E) and givechemicalequations for thereactions at steps (i) to (iv).
Q.26(i) A black coloured compound (B) is formed on passing H2S throughthe solution ofa compound (A) in
NH4OH.
(ii) (B) ontreatment with HCland potassiumchlorate gives (A).
(iii) (A) ontreatment with KCN gives a buffcoloured precipitate which dissolves in excess ofthis reagent
forming acompound (C).
(iv) The compound (C) is changed into a compound (D) when its aqueous solution is boiled.
(v) The solution of (A) was treated with excess of NaHCO3 & then with bromine water. On cooling &
shaking for sometime, a green colour ofcompound (E) is formed. No changes is observed on heating.
Identify(A)to (E) and give chemicalequations.
Q.27(i) A blue coloured compound (A) onheating gives two product (B) & (C).
(ii) A metal(D)is deposited onpassing hydrogenthroughheated (B).

(iii) The solution of (B) in HCl on treatment with the K4[Fe(CN)6] gives a chocolate brown coloured
precipitate ofcompound (E).
(iv) (C) turnslime water milkywhichdisappears on continuous passageof(C) forming a compound (F).
Identify(A) to (F) and give chemicalequations for thereactions at step (i)to (iv).
Q.28(i)Anore (A) onroasting withsodiumcarbonate andlime inthe presenceofair gives two compounds, (B)
and (C).
(ii) Thesolutionof(B)inconc.HClontreatment withpotassiumferrocyanidegivesabluecolourorprecipitate
ofcompound (D).
(iii) The aqueous solution of(C) on treatment with conc. H2SO4 gives a yellow colouredcompound (E).
(iv) Compound (E) whentreated with KClgives anorange red compound(F) which is usedas anoxidising
reagents.
(v) The solutionof(F) ontreatment withoxalic acid and thenwithanexcess ofpotassiumoxalate givesblue
crystals ofcompound (G).
Identify(A) to (G) and give balanced chemicalequations for reactions at step (i) to (v).
Q.29 Complete thefollowing byidentifying (A)to (F).
(i) CuSO45H2O 
 

C
100
(A) 
 

C
230
(B) 
 

C
800
(C) + (D)
(ii) AgNO3 

 

hot
d
Re
(E) + (F) + O2
(Asked in IIT JEE) :
Q.30 CompoundAis a light greensolid. It gives thefollowing tests :
(i) It dissolves in dilH2SO4. NO gas is produced.
(ii) A drop ofKMnO4 is added to the above solution. The pink colour disappears.
(iii) CompoundAis heated strongly, gases B & C withpungent smell, come out.Abrown residue D is left
behind.
(iv) The gasmixture B & Cis passed into a dichromate solution. The solutionturn green.
(v) The greensolution fromstep (iv) gives a white ppt (E) with a solutionofBa(NO3)2.
(vi) Residue D fromstep (iii) is heatedoncharcoalina reducing flame. It gives a magnetic substance.Name
the compoundsA, B, C, D & E.
Q.31 A mixture oftwo salts was treated as follows :
(i) The mixture was heated with MnO2 & concentrated H2SO4, whenyellowish green gaswas liberated.
(ii) The mixture onheating withNaOH solutiongave a gas turnedred litmus blue.
(iii) Itssolutioninwatergaveblueprecipitatewithpotassiumferricyanideandredcolourationwithammonium
thiocyanate.
(iv) The mixture was boiled with KOH and the liberated gas was bubbled through onalkaline solution of
K2HgI4 to give brownprecipitate. Identifythe two salts.
Q.32 Acompound(A) is greenishcrystalline salt, whichgave thefollowing results.
(i) additionofBaCl2 solutionto thesolutionof(A) resultsintheformationofawhiteprecipitate (B), which
is insolublein dilHCl.
(ii) On heating (A), water vapours and two oxides ofsulphur (C) &(D) are liberated leaving a red brown
residue (E).
(iii) (E) dissolvesin warmconcentrated HClto give a yellowsolution(F).
(iv) With H2S the solution (F) yields a pale yellow precipitate (C) which when filtered, leaves a greenish
filtrate(H).
(v) Solution (F) with treatment of thiocyanate ion gives blood red coloured compound (I). Identify the
substances from(A) to (D).
Q.33 Ahydrated metallic salt (A), light greenincolour, on carefulheatinggive a white anhydrous (B).(B) is
soluble in water and its aqueous solutionreacts with NO to give a dark brown compound (C). (B) on
heating gives a brown residue (D) and a mixture of two gases (E) & (F). The gaseous mixture when
passed through acidified permanganate, discharges the pink colour and whenpassed through BaCl2
solution gives a white precipitate. Identify(A) to (F).

Q.34 The gas liberatedonheating a mixtureoftwo salts withNaOH, give a reddishbrownprecipitate withan
alkaline solutionofK2HgI4. The aqueous solutionofthe mixture ontreatment with BaCl2 gives a white
precipitate which is sparinglysoluble in concentrated HCl. On heating the mixture with K2Cr2O7 and
concentrated H2SO4, red vapour (A) are produced. The aqueous solution ofthe mixture gives a deep
blue colouration(B)withpotassiumferricyanide solution. Identifythe radicals.
Q.35 Alight bluishgreencrystalline solid respondsthe following tests:
(i) Its aqueous solutiongives brownprecipitate or colour with alkaline K2HgI4 solution.
(ii) Its aqueous solutions givesblue colour with K3Fe(CN)6 solution.
(iii) Its solution in HClgives white precipitate with BaCl2 solution. Identify the ions present and suggest
formula ofcompound.
Q.36 Anorangesolid (A)onheatinggives a greenresidue(B), a colourlessgas(C) and water vapour.Thedry
gas (C) on passing over heated Mg gave a white solid (D). (D) onreaction with water gave a gas (E)
whichformed dense white fumes withHCl. Identify(A) to (E) giving reactions.
Q.37 (A) isbinarycompound ofaunivalent metal. 1.422 g of(A) reacts completelywith0.321 g ofsulphur is
an evacuated and sealed tube to give 1.743 g of a white crystalline solid (B) that formed a hydrated
double salt (C) withAl2(SO4)3. Identify(A), (B) & (C).
Q.38 When gas (A)is passed through dryKOH at low temperature, a deep red colouredcompound (B) and
a gas (C) are obtained. The gas (A) on reaction with but-2-ene followed bytreatment with Zn | H2O
yields acetaldehyde. Identify(A), (B) & (C).
Q.39 Ascarlet compound ‘A’is treated with concentrated HNO3 to give a chocolate brownprecipitate ‘B’.
The precipitate is filtered and the filtrate is neutralised with NaOH. Addition of KI to the resulting
solution gives a yellow precipitate ‘C’. The precipitate B onwarming with concentrated HNO3 in the
presence ofMn(NO3)2 produces apink coloured solutiondueto the formationof‘D’. Identify‘A’, ‘B’,
‘C’& ‘D’. Write the reaction sequence.
Q.40 Calciumburns in nitrogen to produce a white powder whichdissolves in sufficient water to produce a
gas (A)and analkaline solution. The solutiononexposureto air produces athinsolid layer of(B)onthe
surface. Identifythe compounds (A) and (B).
Q.41 GradualadditionofKI solution to Bi(NO3)3 solutioninitiallyproduces a dark brownprecipitate which
dissolves inexcess ofKI to give a clear yellowsolution. Write equations for the above reactions.
Q.42 A colourless inorganic salt [A] decomposes completelyat about 250°C to give onlytwo products, (B)
and (C) leaving no residue. The oxide (C) is a liquid at roomtemperature and neutralto moist litmus
paper whilethe gas (B) is a neutraloxide. While phosphorus burns in excess of(B) to producea strong
white dehydrating agent. Write balanced equations for the following reactions involved in the above
process.
Q.43(i) Anaqueoussolutionofwhite colouredcompound (A) onreactionwithHClgives awhite precipitate of
compound (B).
(ii) (B) becomes soluble inchlorine water withformation of(C).
(iii) (C) reacts withKI to give a precipitate whichbecomes soluble inexcess ofit forming a compound (D).
Compound (D)is used for detectingammoniumsalt.
(iv) (B) and (C) bothon treatment with SnCl2 give a greyprecipitate of(E).
(v) When conc. H2SO4 is added slowly into a mixture ofcold solution of(A) and FeSO4 a brown ring of
compound (F) is formed. Identify(A) to (F).
Q.44 An aqueous blue coloured solution ofa transition metalsulphate reacts with H2S inacidic mediumto
give a black precipitate (A) whichisinsoluble inwarmaqueoussolution ofKOH. Theblue solution on
treatment withKI in weaklyacidic mediumturns yellow andproduces a white precipitate(B). Identify
the transitionmetalion. Write thechemicalreactions involved inthe formationof(A) and (B).
Q.45(i) Apowdered substance (A) ontreatment withfusion mixture gives a greencoloured compound (B).
(ii) Thesolutionof(B)inboilingwateronacidificationwithdiluteH2SO4 givesapinkcolouredcompound(C).

(iii) The aqueous solution of(A) on treatment with NaOH and Br2 – water gives a compound (D).
(iv) A solution of(D) in conc. HNO3 on treatment with lead peroxide at boiling temperature produced a
compound (E) which was ofthe same colour as that of(C).
(v) Asolutionof(A) indiluteHClontreatment withasolutionofbariumchloride gave a whiteprecipitateof
compound (F) which was insoluble in conc. HNO3 and conc. HCl.
Identify(A) to (F) and give balanced chemicalequations for the reactions at steps (i) to (v).
Q.46 Identifythefollowing:
Na2CO3 
 
 2
SO
A 

 
 3
2CO
Na
B




 
 S
Elemental
C 
 2
I
D
Also mentiontheoxidation state ofS inallthe compounds.
Q.47 AmixtureconsistsA(yellow solid)and B (colourless solid)which gives lilac colourinflame.
(a) Mixture gives black precipitate C on passing H2S (g).
(b) C is soluble in aqua-regia and on evaporation of aqua-regia and adding SnCl2 gives greyish black
precipitate D.
The salt solution withNH4OH gives a brown precipitate.
(i) The sodiumextract ofthe salt with CCl4 / FeCl3 gives a violet layer.
(ii) The sodiumextract givesyellow precipitate withAgNO3 solutionwhichis insolublein NH3.
IdentifyAand B, and the precipitates C and D.
Q.48 Dimethylglyoxime is addedto alcoholic solutionofNiCl2. Whenammoniumhydroxide isslowlyadded
to it a rosy red precipitate ofa complex appears.
(i) Give thestructure ofcomplex showinghydrogen bonds
(ii) Give oxidationstate and hybridizationofcentralmetalion.
(iii) Identifywhether it is paramagnetic or diamagnetic
Q.49 There are two ores (A1)and (A2) ofmetal(M). Whenore (A1) is calcinated a black solid(S) is obtained
alongwiththeliberationofCO2 and water.The ore (A1)ontreatment withHClandKIgivesa precipitate
(P) and iodine is liberated.Another ore (A2) onroasting gives agas (G) and metal(M) is set free. When
gas (G) is passed throughK2Cr2O7 it turns green. Identify(M), (A1), (A2), (S), (P) and (G).
Q.50 Fe3+ 



 


)
excess
(
SCN
blood red(A) 


 


)
excess
(
F
colourless(B)
IdentifyAand B
(a) Write IUPAC name ofAand B
(b) Findout spin onlymagneticmoment ofB
Q.51 ate)
(intermedi
C
A
B
smell
pungent
and
fumes
Brown 3
2 HNO
.
conc
MnO
NaBr



 




 






 
FindA, B, C and D.Also write equationsAto B andAto C.
Q.52
Identifythe metalM and hence MCl4. Explain the difference in colours ofMCl4 andA.