QUALITATIVE ANALYSIS. Contents. Theory Exercise Exercise Exercise Exercise

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1 QUALITATIVE ANALYSIS Topic Contents Page No Theory Exercise Exercise Exercise Exercise Answer Key Syllabus QUALITATIVE ANALYSIS Principles of qualitative analysis : Groups I to V (only Ag, Hg 2, Cu 2, Pb 2, Bi 3, Fe 3, Cr 3, Al 3, Ca 2, Ba 2, Zn 2, Mn 2 and Mg 2 ); Nitrate, halides (excluding fluoride), sulphate and sulphide Name : Contact No

2 QUALITATIVE ANALYSIS Some important points which should be kept in mind while doing the analysis of cations 1 Group 1 st radicals (Ag, Pb2, Hg 2 2 ) are precipitated as chloride because the solubility product of these chlorides (AgCl, PbCl 2, HgCl 2 ) is less than the solubility products of chlorides of all other metal ions, which remain in solution Lead chloride is slightly soluble in water and therefore, lead is never completely precipitated by adding dilute hydrochloric acid to a sample ; the rest of the lead ions are precipitated with H 2 S in acidic medium together with the cations of the second group 2 Group 2 nd radicals are precipitated as sulphides because of their low solubility products whereas sulphides of other metals remain in solution because of their high solubility products HCl acts as a source of H which decreases the concentration of S due to common ion effect Hence, the concentration of S ion is too low that it exceeds only the solubility products of the metal sulphides of II nd group We can not use H 2 inplace of HCl because some cations of higher groups ie v th group will also precipitate as their sulphates like Ba, Sr, Ca etc HN 3 can't be used in place of HCl HN 3 is a powerful oxidising agent HN 3 will oxidize H 2 S forming sulphur (yellow precipitate) or colloidal solution causing confusion with CdS, As 2 S 3 even though Cd 2, As 3 will be absent The colloidal solution is white-yellow and that cannot be filtered causing unnecessary trouble 3 Group 3 rd radicals are precipitated as hydroxides and the addition of NH Cl suppresses the ionisation of NH H so that only the group 3 cations are precipitated as hydroxides because of their low solubility products (i) Excess of NH Cl should not be added, as manganese will precipitate as Mn 2 H 2 (ii) (NH cannot be used in place of NH Cl because the S will also give the precipitate of Ba, Sr etc (iii) While proceeding for 3 rd group from 2 nd group, the filtrate of 2 nd group is boiled off to remove the dissolved H 2 S and then one drop of concentrated HN 3 is added and again boil so that if Fe2 is present is oxidised to Fe 3 The K sp of Fe 2 is higher than Fe 3, therefore, it is partially precipitated and will thus interfere in the analysis of th group radicals In our scheme Fe 2 is not there even if it is present, we shall report only Fe 3 (Fe 2 needs other special tests) (iv) If the medium remains acidic the hydroxides do not precipitate and we would think that Fe 3, Al 3, Cr 3 are absent even though they may be present (v) In place of NH H, NaH solution can't be used for the precipitation as their hydroxides because in excess of it we get soluble complexes of Al 3 and Cr 3 In th group, ammonium hydroxide increases the ionisation of H 2 S by removing H from H 2 S as unionised water H 2 S 2H S ; H H H 2 Now the excess of S ions is available and hence the ionic products of group th group cations exceeds their solubility products and will be precipitated In case H 2 S is passed through a neutral solution, incomplete precipitation will take place due to the formation of HCl, which decreases the ionisation of H 2 S For example MnCl 2 H 2 S MnS 2HCl 5 In 5 th group the reagent ammonium carbonate should be added in alkaline or neutral medium In the absence of ammonia or ammonium ions, magnesium will also be precipitated Ph () () QUALITATIVE ANALYSIS_ADVANCED # 1

3 Physical Examination f the Mixture : The physical examination of the unknown mixture involves the study of colour, smell and density Table : 1 Physical Examination Ex periment bservations Infere nce (a) Colour Blue or Bluish green Cu 2 or Ni 2 Greenish Ni 2 Light green Fe 2 Dark brown Fe 3 Pink, violet Co 2 Light pink, flesh colour or dull earthy colour Mn 2 White Shows the absence of Cu 2,Ni 2,Fe 2,Fe 3 Mn 2, Co 2 (b) Smell Take a pinch of the salt between your fingers and rub with a drop of water (C) Density Ammonical smell NH Vinegar like smell CH 3 C Smell like that of rotten eggs S (i) Heavy Salt of Pb 2 or Ba 2 (ii) Light fluffy powder Carbonate salts (d) Deliquescence Salt absorbs moisture and becomes paste like (i) If coloured, may be Cu(N 3, FeCl 3 (ii) If colourless, may be Zn(N 3, chlorides of Zn 2, Mg 2 etc Dry Heating Test : This test is performed by heating a small amount of mixture in a dry test tube Quite valuable information can be generated by carefully performing and noting the observations here n heating some salts undergo decomposition thus evolving the gases or may undergo characteristic changes in the colour of residue These observations are tabulated below along with the inferences that you can draw Ph () () QUALITATIVE ANALYSIS_ADVANCED # 2

4 Table : 2 BSERVATIN 1 Gas evolved INFERENCE (a) Colourless and odourless gas C 2 gas turns lime water milky C 3 (b) Colourless gas with odour (i) H 2 S gassmells like rotten eggs, turns Hydrated S lead acetate paper black (ii) S 2 gascharacteristic suffocating S 3 smell, turns acidified potassium dichromate solution or paper green (iii) HCl gas Pungent smell, white fumes with Cl ammonia, white precipitate with silver nitrate solution (iv) Acetic acid vapourscharacteristic vinegar CH 3 C like smell (v) NH 3 gas Characteristic smell, turns NH Nessler's solution brown (c) Coloured gases Pungent smell (i) N 2 gas Reddish brown, turns ferrous N 2 or N 3 sulphate solution black (ii) Cl 2 gas Greenish yellow, turns starch Cl iodide paper blue (iii) Br 2 vapours Reddish brown, turns starch Br paper orange red (iv) I 2 vapours Dark violet, turns starch paper blue 2 Sublimate formed (a) White sublimate NH (b) Black sublimate accompanied by violet vapours 3 Fusion The mixture fuses Swelling The mixture swells up into voluminous mass Alkali metal salts or salt containing water of crystallisation P 3, B 3 3 indicated 5 Residue (i) Yellow when hot, white when cold Zn 2 (ii) Brown when hot and yellow when cold Pb 2 (iii) riginal salt blue becomes white on heating Hydrated Cu indicated (iv) Coloured salt becomes brown or black on Co 2, Fe 2, Fe 3, Cr 3, Cu 2, Ni 2, Mn 2 heating indicated Ph () () QUALITATIVE ANALYSIS_ADVANCED # 3

5 Note : Use a perfectly dry testtube for performing this test While drying a testtube, keeps it in slanting position with its mouth slightly downwards so that the drops of water which condense on the upper cooler parts, do not fall back on the hot bottom, as this may break the tube Charcoal Cavity Test : This test is based on the fact that metallic carbonates when heated in a charcoal cavity decompose to give corresponding oxides The oxides appear as coloured incrustation or residue in the cavity In certain cases, the oxides formed partially undergo reduction to the metallic state producing metallic beads or scales Example : (a) Zn Na 2 C 3 ZnC 3 Na 2 ZnC 3 Zn (Yellow when hot, white when cold) C 2 (b) Cu Na 2 C 3 CuC 3 Na 2 CuC 3 Cu C 2 Cu C Cu (Reddish scales) C Table : 3 Inference Incrustation or Residue Metallic bead Yellow when hot, white when cold None Zn 2 Brown when hot, yellow when cold Grey bead which marks the paper Pb 2 No characteristic residue Red beads or scales Cu 2 White residue which glows on heating None Ba 2,Ca 2, Mg 2 Black bservation None Nothing definitegenerally coloured salt Cobalt Nitrate Test : In case the residue is white in colour after charcoal cavity test, add a drop of cobalt nitrate in the charcoal cavity A drop of water is then added and the mass is heated in an oxidising flame using blow pipe It is cooled and one or two drops of cobalt nitrate solution is added and then again heated in the oxidising flame Different metal salts give different coloured mass as given in the table To illustrate : Zn Na 2 C 3 ZnC 3 Na 2 ; ZnC 3 Zn C 2 2Co (N 3 2Co N 2 2 ; Zn Co Zn Co (or CoZn 2 ) (Rinmann's green) Table : Ph () () QUALITATIVE ANALYSIS_ADVANCED #

6 Flame test : The chlorides of the metals are more volatile as compared to other salts and these are prepared in situ by mixing the compounds with a little concentrated hydrochloric acid n heating in a non-luminous Bunsen flame they are volatilized and impart a characteristic colour to the flame as these absorb energy from the flame and transmit the same as light as characteristic colour Table : 5 Colour of Flame Crimson Red / Carmine Red Golden yellow Violet/Lilac Brick red Crimson Apple Green/Yellowish Green Green with a Blue centre/greenish Blue Inference Lithium Sodium Potassium Calcium Strontium Barium Copper Borax Bead test : n Heating borax forms a colourless glassy bead of NaB 2 and B 2 3 Na 2 B 7 10H 2 Na 2 B 7 2NaB 2 B 2 3 n heating with a coloured salt, the glassy bead forms a coloured metaborate in oxidising flame For example, in oxidising flame copper salts give blue bead Cu Cu S 3 ; Cu B 2 3 Cu(B 2 (blue bead) However, in reducing flame the colours may be different due to different reactions 2Cu(B 2 C 2CuB 2 B 2 3 C 2Cu(B 2 2C 2Cu (brown red/red and opaque bead) 2B 2 3 2C Table : 6 Metal Colour in oxidising flame Colour in reducing flame When Hot When Cold When Hot When Cold Copper Green Blue Colourless Brown red Iron Brown yellow Pale yellow/yellow Bottle green Bottle green Chromium Yellow Green Green Green Cobalt Blue Blue Blue Blue Manganese Violet/Amethyst Red/Amethyst Grey/Colourless Grey/Colourless Nickel Violet Brown/Reddish brown Grey Grey Non luminous flame is called oxidising flame Luminous flame is called reducing flame All acid radicals which are in JEE syllabus are colourless and diamagnetic Hence the colour of the salts is only due to the basic radicals Ph () () QUALITATIVE ANALYSIS_ADVANCED # 5

7 BJECTIVE QUESTINS * Marked Questions are having more than one correct option Acid radicals (Anions) 1 Dilute H 2 group 11 Sodium carbonate extract is a mixture of : (A) [Salt Na 2 C 3 HCl] (B) [Salt Na 2 C 3 H 2 ] (C) [Salt CaC 3 HCl] (D) [Salt Na 2 C 3 HN 3 ] 12 For the test of sulphite, the soda extract is acidified with : (A) dil HCl (B) dil HN 3 (C) CH 3 CH (D) None of these 13 Which of the following gives a suffocating gas when treated with dilute HCl? (A) Carbonate (B) Sulphite (C) Sulphate (D) Borate 1* The carbonate of which of the following cation is soluble in water? (A) Na (B) K (C) NH (D) Ca 2 15 The mixture when rubbed with organic acid smells like vinegar obtain It contains : (A) sulphur (B) nitrate (C) nitrite (D) acetate 16 Colourless salt (A) dil H 2 or CH 3 CH Kl blue colour with starch (A) can be : (A) K 2 S 3 (B) Na 2 C 3 (C) NH N 2 (D) NH Cl 17* Zinc pieces are added to acidified solution of S 2 3 Gas liberated can : (A) turn lead acetate paper black (B) turn lime water milky (C) give white precipitate with AgN 3 solution (D) decolourize acidified KMn solution 18 A mixture when rubbed with dilute acid smells like vinegar It contains : (A) sulphite (B) nitrate (C) nitrite (D) acetate 19 A substance on treatment with dilute H 2 liberates a colourless gas which produces (i) turbidity with baryta water and (ii) turns acidified dichromate solution green The reaction indicates the presence of : (A) C 3 (B) S (C) S 3 (D) N An inorganic compound A is dissolved in dilute hydrochloric acid and is then warmed A colourless gas B is produced When a filter paper moistened with potassium iodate and the starch solution is exposed to the gas it turns blue The gas B and the compound A are : (A) S 2 and Na 2 S 3 (B) S 3 and Na 2 (C) H 2 S and Na 2 S (D) H 2 S and Na 2 S Which of the following combines with Fe() ions to form a brown complex? (A) N 2 (B) N (C) N 2 3 (D) N 2 112* Which of the following statements is/are incorrect? (A) A filter paper moistened with cadmium acetate solution turns yellow, when brought in contact with H 2 S gas (B) Both carbonate ions as well as bicarbonate ions in the solutions, give reddish-brown precipitate with mercury(ii) chloride (C) Sulphites in presence of zinc, reacts with dilute H 2 to liberate S 3 gas (D) A filter paper moistened with KI 3 and starch turns blue in contact with S 2 vapours Ph () () QUALITATIVE ANALYSIS_ADVANCED # 6

8 2 Concentrated H 2 group 21 The chromyl chloride test is meant for which of the following ions? (A) Cl ions (B) Both Cl and Br ions (C) I ions (D) Cl and Cr ions 22 Which of the following reagents turns white precipitate of AgCl yellow? (A) NaI (B) Na 3 As 3 (C) Na 3 As (D) NaCN 23 When a mixture of solid NaCl and solid K 2 Cr 2 7 is heated with concentrated H 2, deep red vapours are obtained This is due to the formation of : (A) chromous chloride (B) chromyl chloride (C) chromic chloride (D) chromic sulphate 2 AgCl dissolves in ammonia solution giving : (A) Ag, NH and Cl (B) Ag(NH 3 ) and Cl (C) Ag 2 (NH 3 and Cl (D) Ag(NH 3 and Cl 25 Violet vapours are given out when is treated with conc H 2 : (A) bromide (B) iodide (C) chloride (D) nitrate 26 A mixture upon adding conc H 2 gives deep red fumes It may contain the anions pair : (A) Cr and Cl (B) Br and Cr (C) N 3 and Cl (D) Cr 2 and N A solution of a salt in concentrated sulphuric acid produced a deep blue colour with starch iodide solution The salt may be : (A) chloride (B) carbonate (C) acetate (D) bromide 28 AgCl react with NH 3 & forms a complex : (A) AgN 3 (B) Ag NH 2 Cl (C) Ag (NH 3 Cl (D) Ag mirror 29 A colourless solution of a compound gives a precipitate with AgN 3 solution but no precipitate with a solution of Na 2 C 3 The action of concentrated H 2 on the compound liberates a suffocating reddish brown gas The compound is : (A) Ba(CH 3 C (B) CaCl 2 (C) NaI (D) NaBr 210 When chlorine (Cl 2 ) water in excess is added to a salt solution containing chloroform, chloroform layer turns pale yellow/orange Salt contains : (A) Br (B) (C) N 3 (D) S 211 An aqueous solution of salt containing an acidic radical X reacts with sodium hypochlorite in neutral medium The gas evolved produces blue black colour spot on the starch paper The anion X is : (A) CH 3 C (B) Br (C) I (D) N When chlorine water is added to an aqueous solution of potassium halide in the presence of chloroform, a colour is developed but on adding more of chlorine water the colour disappears, and a colourless solution is obtained This test confirms the presence of the following in aqueous solution (A) Iodide (B) Bromide (C) Chloride (D) Iodide and bromide 213 Nitrate is confirmed by ring test The brown colour of the ring is due to formation of : (A) ferrous nitrite (B) nitroso ferrous sulphate (C) ferrous nitrate (D) Fe N 2 21 Nitrates of all the metals except mercury and bismuth are : (A) coloured (B) unstable (C) soluble in water (D) insoluble in water 215* Which of the following reagents can be used for making the distinction between AgCl and AgI? (A) Sodium arsenite solution (B) Dilute ammonia solution (C) Potassium cyanide solution (D) Dilute HN 3 Ph () () QUALITATIVE ANALYSIS_ADVANCED # 7

9 31 Precipitate of Pb is soluble in : (A) ammonium acetate (6M) (C) dilute H 2 3 Precipitation Reactions (B) dilute HCl (D) none 32 There are four test tubes containing dilute HCl, BaCl 2, CdCl 2 and KN 3 solutions Which of the following reagents will help in the identification of BaCl 2? (A) NaH (B) K 2 Cr (C) AgN 3 (D) both (B) and (C) Basic radical (cations) Zero Group 1 Nessler s reagent is : (A) K 2 Hg (B) K 2 Hg KH (C) K 2 Hg 2 KH (D) K 2 Hg K 2 Ammonia/ammonium ion gives yellow precipitate with : (A) H 2 PtCl 6 (B) HgCl 2 (C) Na 3 [Co(N 2 ) 6 ] (D) (A) and (C) both 3 Ammonium salts on heating with slaked lime liberates a colourless gas (X) Identify the correct statement for gas (X) (A) (X) turns red litmus blue and produces dense white fumes in contact with dilute HCl (B) (X) turns filter paper moistened with mercurous nitrate black and gives intense blue coloured solution with Cu (aq) (C) (X) when passed through Nessler's reagent produces a brown colour precipitate (D) All of these 5 I st Group 51 A metal nitrate reacts with KI solution to give yellow precipitate which on addition of excess of more concentrated solution (6 M) of KI dissolves forming a solution The cation of metal nitrate is : (A) Hg 2 2 (B) Ag (C) Pb 2 (D) Cu 2 52 Three separate samples of a solution of a single salt gave these results ne formed a white precipitate with excess ammonia solution, one formed a white precipitate with dilute NaCl solution and one formed a black precipitate with H 2 S The salt could be : (A) AgN 3 (B) Pb(N 3 (C) Hg(N 3 (D) Mn(N 3 53* White precipitate of silver chloride is soluble in : (A) KCN solution (excess) (C) ammonia solution (B) sodium thiosulphate solution (excess) (D) concentrated solution of KCl 5 Cu 2 and Ag are both present in the same solution To precipitate one of the ions and leaves the other in solution, add : (A) H 2 S (aq) (B) HCl (aq) (C) HN 3 (aq) (D) NH N 3 (aq) 55 Consider the following observation : M n HCl (dilute) Cr 2 white precipitate water soluble The metal ion M n will be : (A) Hg 2 (B) Ag (C) Pb 2 (D) Sn 2 yellow precipitate 56* In which of the following reactions, white precipitate is obtained as one of the reaction products? (A) Pb 2 (aq) C 3 (aq) H 2 () (B) Pb 2 (aq) Br (aq) Products (C) Ag (aq) NH 3 (aq) H 2 () (D) Ag (aq) Cl (aq) Products Products Products 57 A white crystalline substance dissolves in water n passing H 2 S in this solution, a black precipitate is obtained The black precipitate dissolves completely in hot HN 3 n adding a few drops of concentrated H 2, a white precipitate is obtained This precipitate is that of : (A) Ba (B) Sr (C) Pb (D) Cd Ph () () QUALITATIVE ANALYSIS_ADVANCED # 8

10 6 II nd Group 61 Sometimes yellow turbidity appears while passing H 2 S gas even in slightly acidic medium the absence of group radicals This is because : (A) sulphur is present in the mixture as impurity (B) IV group radicals are precipitated as sulphides (C) of the oxidation of H 2 S gas by some acid radicals (D) group radicals are precipitated as hydroxides 62 H 2 S in the presence of HCl precipitates group but not V group because : (A) HCl activates H 2 S (B) HCl increases concentration of Cl (C) HCl decreases concentration of S (D) HCl lowers the solubility of H 2 S in solution 63 Yellow ammonium sulphide solution is a suitable reagent for the separation of : (A) HgS and PbS (B) PbS and Bi 2 S 3 (C) Bi 2 S 3 and CuS (D) CdS and As 2 S 3 6 In which of the following pairs the precipitates are red and black coloured respectively and both precipitates are soluble in excess KI solution? (A) HgI 2, Hg 2 I 2 (B) HgI 2, BiI 3 (C) Cu 2 I 2, AgI (D) CdI 2, PbI 2 65 Which one of the following salts will produce clear and transparent original solution in 2M HCl? (A) Ag 2 C 3 (B) Pb(C 3 (C) Hg 2 C 3 (D) CuC 3 66 A metal chloride original solution (ie S) on mixing with K 2 Cr solution gives a yellow precipitate soluble in aqueous sodium hydroxide The metal may be : (A) mercury (B) iron (C) silver (D) lead 67 Which of the following is insoluble in dil HN 3 but dissolves in aquaregia? (A) HgS (B) PbS (C) Bi 2 S 3 (D) CuS 68 When small amount of SnCl 2 is added to a solution of Hg 2 ions, a silky while precipitate is obtained The silky white precipitate is due to the formation of : (A) Hg 2 Cl 2 (B) SnCl (C) Sn (D) Hg 69 Which of the following reagents gives white precipitate with Hg(N 3 solution? (A) Cobalt (II) thiocyanate (B) Tin (II) chloride (excess) (C) Ammonia solution (D) Potassium cyanide solution 610 When excess of dilute NH H is added to an aqueous solution of copper sulphate an intense blue colour is developed This is due to the formation of : (A) [Cu(NH 3 ) 6 ] 2 (B) Cu(H (C) [Cu(NH 3 ) ] 2 (D) (NH 611 A black sulphide is formed by the action of H 2 S on : (A) cupric chloride (B) cadmium chloride (C) zinc chloride (D) ferric chloride 612* Cu 2 ions will be reduced to Cu ions by the addition of an aqueous solution of : (A) KI (B) KCl (C) KSCN (D) KCN 613 When bismuth chloride is poured into a large volume of water the white precipitate produced is of : (A) BiH (B) Bi 2 3 (C) BiCl (D) Bi (H) 3 61* Which of the following is/are not correctly matched? (A) BiI 3 (C) PbI 2 Black (B) Cu 2 I 2 White precipitate Yellow precipitate (D) HgI 2 Red precipitate Ph () () QUALITATIVE ANALYSIS_ADVANCED # 9

11 7 III rd Group 71 When NH Cl is added to a solution of NH H : (A) the dissociation of NH H increases (C) the concentrations of both H an NH increase (B) the concentration of H increases (D) the concentration of H ion decreases 72 The solution of sodium meta aluminate on diluting with water and then boiling with ammonium chloride gives: (A) [Al(H 2 ) 5 H] 2 (B) AlCl 3 (C) Al (H) 3 (D) NaAl(H) 73 An original solution of an inorganic salt in dilute HCl gives a brown colouration with potassium hexacyanidoferrate (III) and reddish brown colouration with sodium acetate solution The cation of the salt is : (A) Ni 2 (B) Fe 3 (C) Cu 2 (D) none 7 Intense blue precipitate of Fe [Fe(CN) 6 ] 3 and potassium hydroxide solution when mixed gives : (A) K 2 Fe[Fe(CN) 6 ] - white precipitate (B) Fe(H) 3 - reddishbrown precipitate (C) Fe(CN) 3 reddishbrown precipitate (D) KFe[Fe(CN) 6 ] - Turnbull's blue 75 Turnbull s blue is a (A) ferricyanide (B) ferrous ferricyanide (C) ferrous cyanide (D) ferri ferrocyanide 76 Fe(H) 3 and Cr(H) 3 precipitates can be completely separated by : (A) Aq NH 3 (B) HCl (C) NaH/H 2 2 (D) H 2 77 Ferric alum gives deep red colour with NH SCN due to the formation of : (A) Al(SCN) 3 (B) [Fe(SCN) 3 ] (C) Fe(SCN) 3 (D) none of these 78 NH SCN can be used to test one or more out of Fe 3, Co 2,Cu 2 : (A) Fe 3 only (B) Co 2, Cu 2 only (C) Fe 3 Cu 2 only (D) All 79 K [Fe(CN) 6 ] can be used to detect one or more out of Fe 2, Fe 3, Zn 2, Cu 2, Ag, Ca 2 : (A) only Fe 2, Fe 3 (B) only Fe 3,Zn 2,Cu 2 (C) all but not Ca 2 (D) all of these 8 IV th Group 81 To increase significantly the concentration of free Zn 2 ion in a solution of the complex ion [Zn(NH 3 ) ] 2 Zn 2 (aq) NH 3 (aq) [Zn(NH 3 ) ] 2 (aq) add to the solution some : (A) H 2 (B) HCl (aq) (C) NH 3 (aq) (D) NH Cl (aq) 82 CoS (black) obtained in group IV of salt analysis is dissolved in aqua regia and is treated with an excess of NaHC 3 and then Br 2 water An apple green coloured stable complex is formed It is : (A) sodium cobaltocarbonate (B) sodium cobaltibromide (C) sodium cobalticarbonate (D) sodium cobaltobromide 83 A metal salt solution when treated with dimethyl glyoxime and NH H gives a rose red complex The metal is: (A) Ni (B) Zn (C) Co (D) Mn 8 An aqueous solution of colourless metal sulphate M, gives a white precipitate with NH H This was soluble in excess of NH H n passing H 2 S through this solution a white precipitate is formed The metal M in the salt is : (A) Ca (B) Ba (C) Al (D) Zn 85 Which one of the following ions does not give borax bead test? (A) Cr 3 (B) Cu 2 (C) Mn 2 (D) Zn 2 Ph () () QUALITATIVE ANALYSIS_ADVANCED # 10

12 86 Which of the following compound is formed in borax bead test? (A) rthoborate (B) Metaborate (C) Double oxide (D) Tetraborate 87* White precipitate of Zn(H dissolves in : (A) sodium hydroxide solution (C) ammonia solution (B) acid solution (D) solution of ammonium salts 88* Select the correct statements with respect to the manganese nitrate solution in water (A) It gives pink precipitate of Mn(NH )P 7H 2 with Na 2 HP, in the presence of ammonia solution (B) It gives white precipitate of Mn(H with sodium hydroxide which rapidly oxidises on exposure to air, becoming brown (C) n boiling with Pb 2 and concentrated HN 3, a violet-red coloured product is obtained (D) It gives white precipitate of manganese(ii) sulphide with ammonium sulphide solution 9 V th and VI th Group 91 Aqueous Solution of BaBr 2 gives yellow precipitate with : (A) K 2 Cr (B) AgN 3 (C) (CH 3 C Pb (D) (A) and (B) both 92 The addition of K 2 C 3 (aq) to the following solution is expected to produce a precipitate in every case but that one which does not produce precipitate is : (A) BaCl 2 (aq) (B) CaBr 2 (aq) (C) Na 2 (aq) (D) Pb(N 3 (aq) 93 An aqueous solution of salt gives white precipitate with AgN 3 solution as well as with dilute H 2 It may be: (A) Pb(N 3 (B) Ba(N 3 (C) BaCl 2 (D) CuCl 2 9 If crimson flame is given when an inorganic mixture is tested by flame test, it may be due to the presence of: (A) potassium (B) strontium (C) barium (D) calcium 95 A brick red colour is imparted to Bunsen flame by a : (A) Ca salt (B) Sr salt (C) Na salt (D) Co salt 96 The presence of magnesium is confirmed in the qualitative analysis by : (A) titan yellow solution 2M NaH solution (B) disodium hydrogen phosphate NH Cl NH 3 (aq) (C) magneson(i) reagent (D) all of these 97* Which of the following solutions give white precipitate with Pb(N 3 as well as with Ba(N 3? (A) Sodium chloride (B) Sodium sulphate (C) Disodium hydrogen phosphite (D) Sodium chromate 98 Mg is not precipitated in V group because : (A) MgC 3 is soluble in water (C) MgC 3 is soluble in NH H (B) K sp of MgC 3 is high (D) None Ph () () QUALITATIVE ANALYSIS_ADVANCED # 11

13 PART-I : BJECTIVE QUESTINS Single Correct Answer Type 1 When H 2 S is passed through an ammonical salt solution X, a white precipitate is obtained Then X can be a : (A) Co 2 solution (B) Mn 2 solution (C) Ni 2 solution (D) Zn 2 solution 2 In third group, bromine water is used to test : (A) Fe 3 ions (B) Cr 3 ions (C) Al 3 ions (D) All of these 3 In IV group analysis NH H is added before passing H 2 S gas because : (A) The sulphides of IV group are insoluble in NH H (B) The sulphides of other metals are soluble in NH H (C) The concentration of S 2- ions is increased (D) The sulphides of second group are soluble in NH H An aq solution containing Hg 2 2 ; Hg 2, Pb 2 and Cd 2 ions is mixed with dil HCl Which will be precipitated? (A) Hg 2 Cl 2 (B) PbCl 2 (C) Both (A) and (B) (D) None of these 5 Disodium hydrogen phoshate is used to test : (A) Mg 2 (B) Na (C) Ca 2 (D) All 6 An inorganic salt solution on treatment with HCl gives a white precipitate of which metal ions? (A) Hg 2 2 (B) Hg 2 (C) Zn 2 (D) Cd 2 7 An inorganic salt solution gives a yellow preceipte with silver nitrate The precipitate dissolves in dilute nitric acid as well as in ammonium hydroxide The solution contains : (A) bromide (B) iodide (C) phosphate (D) chromate 8 Which of the following salts will turn water coloured when fumes evolved on treatment with conc H 2 are passed in water? (A) Nitrate (B) Bromide (C) Both (D) None 9 A salt which gives C 2 with hot conc H 2 and also decolourizes acidified KMn on warming is: (A) bicarbonate (B) carbonate (C) oxalate (D) acetate 10 Na 2 C 3 cannot be used in place of (NH C 3 for the precipitation of V group, because : (A) Na interferes in the detection of V group (B) concof C 3 is very low (C) Na will react with acid radicals (D) Mg will be precipitated 11 Which gives blood red colour with ammonium thiocyanate? (A) Fe 3 (B) Fe 2 (C) Cu 2 (D) Cd 2 12 In III group precipitation NH Cl is added before adding NH H due to : (A) decreasing conc of H (B) prevent interference of P 3 (C) increase in conc of Cl (D) increase in conc of H ions 13 Few drops of HN 3 are added to II group filtrate before proceeding to III group in order to : (A) convert Fe 2 to Fe 3 (B) convert Fe 3 to Fe 2 (C) precipitate III group (D) none Ph () () QUALITATIVE ANALYSIS_ADVANCED # 12

14 1 The sulphides of which one of the following groups of elements are soluble in yellow ammonium sulphide? (A) As, Sb and Sn (B) As, Cd and Sn (C) Cd, Cu and Bi (D) Hg, Cu and Cd 15 How do we differentiate between Fe 3 and Cr 3 in group III? (A) By adding excess of NH H solution (B) By increasing NH ion concentration (C) By decreasing H ion concentration (D) Both (B) and (C) 16 salt X NaH Heat Y (gas) Gives brown (Mg 3 N 2 H 2 ) ring test Salt X is : (A) NH N 3 (B) NH Cl (C) KN 3 (D) Ba(N 3 17 (KCl K Cr H S ) Heat Red Gas X Pb(Ac Yellow Solution dil NaH The formula and colour of X are respectively : (A) Cr 2 Cl 2, red colour (B) PbCr, yellow colour (C) BaCr, Green Colour (D) Cr 2 ( ) 3, Green Colour 18 A substance on treatment with dil H 2 liberates a colourless gas which produces : (i) turbidity with baryta water and (ii) turns acidified dichromate solution green The reaction indicates the presence of : (A) C 3 2 (B) S 2 (C) S 3 2 (D) N 2 19 The gas G will show which of the following property? (A) It turns lead acetate filter paper black (B) It turns acidified K 2 Cr 2 7 filter paper green (C) It produces purple colouration on filter paper moistened with sodium nitroprusside already made alkaline with sodium hydroxide (D) All of these Ph () () QUALITATIVE ANALYSIS_ADVANCED # 13

15 20 Consider following reaction ; Nitrite Acetic acid Thiourea N 2 SCN 2H 2 Formation of the product in the above reaction can be identified by : (A) FeCl 3 / dilute HCl, when blood red colour appears (B) FeCl 3 / dilute HCl, when blue colour appears (C) K 2 Cr 2 7 / HCl, when green colour appear (D) KMn / HCl, when colourless solution is formed 21 White precipitate of AgCl turns to greyish or black when : (A) reacts with Na 3 As (B) exposed to sunlight (C) reacts with K 2 Cr (D) reacts with concentrated HCl 22 A mixture of two colourless substances was dissolved in water When gaseous Cl 2 was passed through the solution, containing small quantity of CCl a violet colour developed in organic layer Addition of BaCl 2 to the original solution give a white precipitate The mixture contains : (A) salts of nitrate and chloride (B) salts of bromide and chloride (C) salts of iodide and sulphate (D) salts of sulphate and chloride 23 A white crystalline solid (A) on boiling with caustic soda solution gave a gas (B), which when passed through an alkaline solution of potassium mercuric iodide gave brown precipitate The substance (A) on heating gave a gas (X), which rekindled a glowing splinter but did not give brown fumes with nitric oxide The gas (B) is : (A) H 2 S (B) NH 3 (C) HCl (D) C 2 2 An aqueous solution of compound 'A' gives white precipitate with 2M HCl The precipitate becomes black on addition of aqueous NH 3 due to formation of B B dissolves in aquaregia A and B are : (A) Hg 2 and Hg Cl 2 (B) Hg 2 2 and Hg 2 Cl 2 (C) Hg 2 and Hg (NH 2 ) Cl Hg (D) Hg 2 2 and Hg (NH 2 ) Cl Hg 25 A compound (X) reacts in the following ways The compound (X) is likely to be (A) Pb(N 3 (B) CaCr (C) Hg(N 3 (D) AgN 3 26 To a solution of a substance, gradual addition of ammonium hydroxide results in a brownish black precipitate which does not dissolve in excess of NH H However, when KI (not in excess) is added to the original solution, a green precipitate is formed The solution contained : (A) lead salt (B) silver salt (C) mercurous salt (D) copper salt 27 Black precipitate of copper sulphide dissolves in : (A) KCN solution (B) sodium sulphide solution (C) sodium hydroxide (D) boiling dilute (M) sulphuric acid 28 Which of the following metal salts gives a red and opaque borax bead in the reducing flame (in cold)? (A) Ni (B) Fe (C) Cu (D) Mn 29 Which one among the following pairs of ions cannot be separated by H 2 S in dilute hydrochloric acid? (A) Bi 3, Sn (B) Al 3, Hg 2 (C) Zn 2, Cu 2 (D) Ni 2, Cu 2 30 The reagents, NH Cl and aqueous NH 3 will precipitate : (A) Ca 2 (B) Al 3 (C) Mg 2 (D) Zn 2 Ph () () QUALITATIVE ANALYSIS_ADVANCED # 1

16 31 In the precipitation of the iron group in qualitative analysis, ammonium chloride is added before adding ammonium hydroxide to : (A) decrease concentration of H ions (B) prevent interference by phosphate ions (C) increase concentration of Cl ions (D) increase concentration of NH ions 32 Which one of the following can be used in place of NH Cl for the identification of the third group radicals? (A) NH N 3 (B) (NH (C) (NH C 3 (D) NaCl 33 Which one of the following metal salts produces a blue coloured bead in cobalt nitrate charcoal cavity test? (A) Zn 2 (B) Mg 2 (C) Sn 2 (D) Al 3 3 Which of the following is correct? (A) AgCl(s) Na 3 As 3 colourless solution (B) FeCl 3 (aq) K Fe(CN) 6 brown precipitate (C) FeCl 3 (aq) K 3 Fe(CN) 6 brown colouration (D) Cu (aq) KCN (excess) blue colouration 35 Fe 2 does not give prussian blue colour with K [Fe(CN) 6 ] but on its reaction with (X), prussian blue colour appears (X) can be : (A) Mn / H (B) Zn/NaH (C) NH 3 (aq) (D) all true 36 When HN 3 is added to sodium ferrocyanide, which of the following observation is observed? (A) NaFe[Fe(CN) 6 ] is produced (B) Fe [Fe(CN) 6 ] 3 is formed (C) Fe 3 [Fe(CN) 6 ] 2 is formed (D) Na 2 [Fe(CN) 5 (N) ] is formed 37 What product is formed by mixing the solution of K [Fe(CN) 6 ] with the solution of FeCl 2 in complete absence of air? (A) Ferro ferricyanide (B) Ferric ferrocyanide (C) Ferric ferricyanide (D) None 38 Select the correct statement with respect to Fe 3 ions (A) Iron (III) ions react with H 2 S in acidic solution to give a black precipitate of Fe 2 S 3 (B) Iron (III) ions react with ammonium sulphide to give the black precipitate of Fe 2 S 3 (C) Iron (III) ions react with ammonium thiocyanate solution to produce deep red colouration (D) All of these 39 Which one of the following compounds on reaction with Na 2 2 in alkaline medium gives yellow colour solution? (A) Cr (H) 3 (B) Zn(H (C) Al(H) 3 (D) None of these 0 A dark green bead in the borax bead test (in oxidising flame) indicates the presence of : (A) Cr 3 (B) Mn 2 (C) Co 2 (D) Ni 2 1 Which of the following cation does not give red colour precipitate/solution with dimethylglyoxime (DMG) in alkaline solution? (A) Zn 2 (B) Ni 2 (C) Fe 2 (D) both (A) and (C) 2 A suspension containing insoluble substances ZnS, MnS, HgS, Ag 2 S and FeS, is treated with 2N HCl n filtering, the filtrate contains appreciable amounts of which one of the following? (A) Zinc and mercury (B) Silver and iron (C) Manganese and mercury (D) Zinc, manganese and iron 3 An aqueous solution contains both Al 3 & Zn 2 To this solution NH H is added in excess (A) nly Al(H) 3 will be precipitated (B) nly Zn(H will be precipitated (C) Both will be precipitated (D) No precipitate will appear A metal M and its compound can give the following observable changes in a sequence of reactions, very dilute M Colourless solution HN 3 and no gas is evolved NaH aqueous White excess Colourless H2S / H precipitate NaH(aq) solution The metal M can be : (A) Mg (B) Pb (C) Zn (D) Sn White precipitate Ph () () QUALITATIVE ANALYSIS_ADVANCED # 15

17 5 In fifth group, (NH C 3 is added to precipitate out the carbonates We do not add Na 2 C 3 because : (A) CaC 3 is soluble in Na 2 C 3 (B) Na 2 C 3 increases the solubility of fifth group carbonates (C) MgC 3 will be precipitated out in fifth group (D) none 6 A metal salt solution forms a yellow precipitate with potassium chromate in acetic acid, a white precipitate with dilute sulphuric acid, but gives no precipitate with sodium chloride or iodide, it is : (A) lead carbonate (B) basic lead carbonate (C) barium carbonate (D) strontium carbonate Multiple Correct Answer(s) Type : 7 Cu 2 ions give white precipitate with : (A) potassium iodide solution (B) potassium thiocyanate and saturated solution of S 2 (C) excess potassium cyanide solution (D) potassium hydroxide solution 8 Which of the following statements is/are true? (A) Ag ions do not give white precipitate with concentrated HCl (B) Cu 2 ions produce a white precipitate when KCN solution is added in a small quantity (C) Hg 2 ions give deep blue precipitate with cobalt acetate and ammonium thiocyanate (D) Black precipitate of BiI 3 turns orange when heated with water 9 Na 2 and Na 2 S can be distinguished from each other by using : (A) dilute H 2 (B) acidified KMn solution (C) sodium nitroprusside solution (D) cadmium acetate solution 50 K solution is the reagent for : (A) Hg 2 (B) Pb 2 (C) Ag (D) Cu 2 51 Which of the following cations form(s) black precipitate(s) with H 2 S (g)? (A) Cu 2 (B) Sb 3 (C) Pb 2 (D) Bi 3 52 In B group of basic radicals, the yellow precipitate (s) is/are given by : (A) As 3 (B) Sb 3 (C) Sn (D) Sn 2 53 Borax bead test is given by : (A) Co 2 (B) Zn 2 (C) Cu 2 (D) Ni 2 5 Which of the following anion(s) evolve(s) reddish brown gas with concentrated H 2? (A) Br (B) N 3 (C) S 3 (D) 55 Concentrated aqueous ammonia dissolve(s) which of the following completely? (A) AgCl (B) AgBr (C) Ag 2 Cr (D) Ag 56 Hg 2 I 2 (green) boiled products with H2 Which of the following statement is correct with respect to the products? (A) Black precipitate of mercury(i) oxide is formed (B) Violet colour gas is evolved (C) Red precipitate of HgI 2 is formed (D) Mercury is obtained 57 H 2 S will precipitate the sulphide of all the metals from the solution of chlorides of Cu, Zn and Cd if : (A) the solution is aqueous (B) the solution is acidic (C) the solution is slightly acidic (D) solution is alkaline Ph () () QUALITATIVE ANALYSIS_ADVANCED # 16

18 58 Which of the following statement(s) is /are false? (A) Fe 3 gives red precipitate with dimethyl glyoxime in alkaline solution (B) Cu 2 ion with potassium iodide solution gives a dirty brownish white precipitate which turns white on adding hypo solution (C) A filter paper soaked in mercurous nitrate turns black in contact with ammonia gas (D) Ag 2 does not dissolve in nitric acid and ammonia solution 59 Which of the following compound(s) is /are insoluble in excess aqueous sodium hydroxide? (A) ZnCl 2 (B) CdCl 2 (C) AlCl 3 (D) MnCl 2 60 Ammonium molybdate test is used for the estimation of : (A) P 3 (B) Mg 2 (C) As 3 (D) CH 3 C 61 Which of the following statement(s) is/are true? (A) Titan yellow solution gives red colouration with a neutral solution containing Mg 2 ions (B) Solution of nitrite is decomposed by sulphamic acid (C) Fe 2 ions give brown colour precipitate with [Fe(CN) 6 ] 3 ions solution (D) Green precipitate of Cr(H) 3 is soluble in Na Which of the following is/are correct for potassium ferrocyanide? (A) It gives a brown precipitate with Cu 2 ions (B) It gives a white precipitate of mixed salt with Ca 2 ions (C) It in excess gives a bluish white/white precipitate with Zn 2 (D) It develops a deep red colouration with Fe 3 63 CoCl 2 KN 2 CH 3 CH [X] H 2 KCl CH 3 CK N (Unbalenced equation) (A) X is a yellow crystalline solid insoluble in water (B) X is a green coloured compounds knwon as kinman's green (C) IUPAC name of X is potassium hexanitrito N cobaltate (II) (D) The compound X is an inner orbital complex 6 Consider the reactions shown below ; Which of the following statement (s) is/are correct? (A) [X] is a yellow coloured precipitate (B) [X] is soluble in ammonia solution (C) [Y] gives green coloured solution with excess of sodium hydroxide solution (D) The conversion of Cr 2 7 to [Y] is an redox reaction PART-II SUBJECTIVE QUESTINS 1 What will happen if to a solution of Ca(HC 3, formed by passing the carbon dioxide through a milky solution of CaC 3 for a longer time, ammonia solution is added? 2 Write the names of the acidic radicals which can be tested by aqueous solution of barium chloride 3 What will happen if to a white precipitate of BaS 3, bromine water is added? Ph () () QUALITATIVE ANALYSIS_ADVANCED # 17

19 A nitrite solution is added to a saturated solution of iron(ii) acidified with dilute acetic acid or with dilute sulphuric acid If any reactions occours then write the name and chemical composition of the product formed Write also the chemical equations involved 5 What happens when a sulphite reacts with dilute H 2 in presence of zinc? 6 A compound containing acetate radical is made to react with neutral ferric chloride The solution is then diluted with water and boiled for 1-2 minutes A reddish brown precipitate is obtained Give the chemical composition of reddish brown precipitate 7 In which reagents the AgCl precipitate is soluble? 8 In which of the following reagents, the white precipitate of Pb is soluble? dilute HCl, hot concentrated H 2, ammonium acetate (6M), ammonium tartrate 6M in the presence of ammonia, sodium hydroxide solution 9 Mercuric nitrate solution reacts with a soluble sulphate forming a yellow precipitate If the statement is true then explain giving the complete balanced equation 10 What is the formula of iodide of Millon's base? 11 What happens when ammonia gas is passed into a solution of sodium cobaltinitrite? 12 When calomel reacts with ammonia solution, a black precipitate is formed Write the chemical equation and also name the reaction nature 13 What products are formed when precipitate formed by the reaction of Hg 2 2 ions and excess of sodium hydroxide solution is boiled? 1 In which of the reagent, white precipitate of Pb 3 (P is soluble? 15 Why do lead salts turn black on keeping for a long time in the laboratory? 16 Name one chloride which is soluble in hot water as well as in excess of HCl 17 Does mercuric sulphide dissolve in sodium sulphide solution (of 2M)? 18 What happens when white precipitate of Bi(H) 3 is boiled? 19 Why Na 2 S cannot be used in place of H 2 S (in presence of HCl) as a reagent for II nd group cations? 20 Is their any reaction other then cyanide reaction which can be used for the differentiation of Cu 2 and Cd 2 ions? 21 Which basic radical is tested with the help of alkaline sodium stannite? 22 What happens when ammonium sulphide solution reacts with a solution containing a Cr(III) salt? 23 Do Fe(III) salts and Fe(II) salts both give red colouration with dimethylglyoxime in ammonical solution If not then which iron salt gives red colouration with dimethylglyoxime? 2 Which colour precipitate is formed by Fe(II) salt with potassium ferrocyanide, (i) in complete absence of air and (ii) under ordinary atmospheric condition? 25 Partial precipitation of Mn 2 as Mn(H occurs with ammonia solution but the precipitate is soluble in ammonium salts Explain? Ph () () QUALITATIVE ANALYSIS_ADVANCED # 18

20 26 What happens when Mn(II) ions free from chloride ions react with acidified solution of (NH S 2 8 or K 2 S 2 8 in presence of a few drops of AgN 3 solution? 27 Why Zn(II) salt is not precipitated as Zn(H by ammonia solution in the presence of excess of ammonium chloride? 28 What will happen if the precipitation of V th group cation by ammonium carbonate is carried out in neutral medium? 29 What happens when ammonium sulphate solution is added to a solution containing both Sr 2 and Ca 2 ions? 30 Which colour precipitate is obtained when a solution of Ca 2 ions reacts with potassium ferrocyanide 31 Salt H 2 (dilute) Coloured vapours which turns starch iodide paper blue Identify the acid radical and the coloured vapours giving the relevant chemical equations 32 Which chloride of st group basic radicals turns black on treatment with NH 3? 33 Which basic radicals form oxo-cations in aqueous solutions? 3 Which ions cannot co-exist in solution? 35 Which radical of group IV th gives bluish white / white precipitate with excess K [Fe(CN) 6 ]? 36 What products are formed? When : (i) Disodium hydrogen phosphate is added to magnesium sulphate in presence of ammonium chloride and aqueous ammonia (ii) A solution containing Zn 2 ions is poured in an aqueous ammonia (iii) Bi(N 3 ) 3 solution is mixed with K and then resulting precipitate is heated with water (iv) Disodium hydrogen phosphate is boiled with concentrated HN 3 and ammonium molybdate reagent 37 Complete and balance the following chemical reactions (i) Cu(B 2 C fused (ii) AgBr concentrated NH 3 (iii) Cr(H) 3 Na 2 C 3 KN 3 (v) CaS 3 S 2 H 2 fused (iv) Cu(N 3 38 Complete and balance the following reaction (i) Na 2 S CdC 3 (ii) CoCl 2 NH SCN Ether 39 A black coloured compound (A) on reaction with dilute H 2 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 of a compound (E) gives a precipitate (F) soluble in dilute HN 3 After boiling this solution when an excess of NH H is added, a intense blue coloured compound (G) is formed To this solution on addition of acetic acid and aqueous K [Fe(CN) 6 ] a chocolate brown precipitate (H) is obtained n addition of an aqueous solution of BaCl 2 to an aqueous solution of (E) a white precipitate insoluble in dilute HCl is obtained Identify the compounds from (A) to (H) Ph () () QUALITATIVE ANALYSIS_ADVANCED # 19

21 0 A compound (A) is greenish crystalline salt, which gave the following reactions (i) Addition of BaCl 2 solution to the solution of (A) results in the formation of white precipitate (B) which is insoluble in dilute HCl (ii) n heating (A), water vapours and two oxides of sulphur (C) and (D) are liberated leaving a red brown residue (E) (iii) (E) dissolves in warm concentrated HCl to give a yellow solution (F) (iv) Solution (F) on treatment with thiocyanate ions gives blood red coloured compound (G) Identify the compounds from (A) to (G) 1 An aqueous solution of salt (A) gives a white crystalline precipitate (B) with NaCl solution The white precipitate turns black forming (C) when H 2 S gas is passed through it Compound (B) dissolves in hot water and the resulting solution gives yellow precipitate (D) with KI or yellow precipitate with K 2 Cr or white precipitate with dilute H 2 which is insoluble in C 2 H 5 H The compound (A) does not evolve any gas with dilute HCl but liberates a reddish brown gas on heating Identify the compounds (A) to (D) 2 A white substance (A) reacts with dilute H 2 to produce a colourless gas (B) and a colourless solution (C) The reaction between (B) and acidified K 2 Cr 2 7 solution produces a green solution and a slightly coloured precipitate (D) The substance (D) burns in air to produce a gas (E) which reacts with (B) to yield (D) and a colourless liquid Anhydrous copper sulphate is turned blue on addition of this colourless liquid Addition of aqueous NH 3 or NaH to (C) produces first a white precipitate which dissolves in the excess of the respective reagent to produce a clear solution in each case Identify (A), (B), (C), (D) and (E) 3 A mixture of two salts was treated as follows (i) The mixture was heated with precipitated Mn 2 and concentrated H 2 when a yellowish green gas was liberated (ii) The mixture on heating with NaH solution gave a gas which turned red litmus blue (iii) Its solution in water gave red colouration with dimethylglyoxime in alkaline solution and white precipitate with K [Fe(CN) 6 ] in absence of air (iv) The mixture was boiled with KH and the liberated gas was bubbled through an alkaline solution of K 2 Hg to give a brown precipitate Identify the ions present in the mixture (i) A yellow coloured precipitate of compound (A) is formed on passing H 2 S through a neutral solution of a salt (B) (ii) (A) is soluble in hot dilute HN 3, but insoluble in yellow ammonium sulphide (iii) The solution of (B) on treatment with small quantity of NH 3 gives white precipitate which becomes soluble in excess of it forming a compound (C) (iv) The solution of (B) gives white precipitate with small concentration of KCN which becomes soluble in excess of this regent forming a compound (D) (v) The solution of (D) on treatment with H 2 S gives (A) (vi) The solution of (B) in dilute HCl on treatment with a solution of BaCl 2 gives white precipitate of compound (E) which is insoluble in concentrated HN 3 Identify compounds (A) to (E) 5 (i) An aqueous solution of a compound (A) is acidic towards litmus and (A) is sublimed at about 300ºC (ii) (A) on treatment with an excess of NH SCN gives a red coloured compound (B) and on treatment with a solution of K Fe(CN) 6 gives a blue coloured compound (C) (iii) (A) on heating with excess of solid K 2 Cr 2 7 in presence of concentrated H 2 gives deep red vapour of (D) (iv) n passing vapour of (D) into a solution of NaH and then adding the solution of acetic and lead acetate, a yellow precipitate of compound (E) is obtained Identify (A) to (E) and give chemical equations for the reactions at steps (ii) to (iv) 6 (i) A blue coloured compound (A) on heating gives two product (B) & (C) (ii) A metal (D) is deposited on passing hydrogen through heated (B) (iii) The solution of (B) in HCl on treatment with the [Fe(CN) 6 ] gives a chocolate brown coloured precipitate of compound (E) (iv) (C) turns lime water milky which disappears on continuous passage of (C) forming a compound (F) Identify (A) to (F) and give chemical equations for the reactions at step (i) to (iv) Ph () () QUALITATIVE ANALYSIS_ADVANCED # 20

22 7 (i) A black coloured compound (B) is formed on passing H 2 S through the solution of a compound (A) in NH H (ii) (B) on treatment with HCl and potassium chlorate or aquaregia gives (A) (iii) (A) on treatment with KCN gives a buff / reddish-brown coloured precipitate which dissolves in excess of this reagent forming a compound (C) (iv) The compound (C) is changed into a compound (D) when its aqueous solution is boiled in air (v) The solution of (A) was treated with excess of NaHC 3 & then with bromine water n cooling & shaking for some time, a green colour of compound (E) is formed No change is observed on heating Identify (A) to (E) and give chemical equations 8 What happens when nitrobenzene diazonium chloride reagent reacts with an ammonium salt in the presence of sodium hydroxide solution? 9 Why in cobalt nitrate test for aluminium salts, excess of cobalt nitrate should not be added? 50 What happens when? (a) To a Zn 2 ions solution faintly acidified with 2M acetic acid, 01 ml of 025 M Cu solution and 2 ml of ammonium tetrathiocyanatomercurate(ii) reagent is added (b) The above test is performed in absence of Cu solution 1 MATCH THE CLUMN 11 Match the colour of the precipitates with their respective compounds (molecular formula) obtained in the analysis of different cations Column Column (A) White crystalline precipitate (p) K 3 [Co(N 2 ) 6 ] (B) Reddish brown precipitate (q) Cr(H) 3 (C) Yellow precipitate (r) Fe(H) 3 (D) Green precipitate (s) PbCl 2 (t) Cu 3 [Fe(CN) 6 ] 2 12 Match the products of the reactions listed in column-i with the colour of the precipitate(s) listed in column-ii Column I Column II (A) Hg 2 I 2 (green) boiling H2 (p) Grey / Black precipitate (B) BiI 3 (black) H 2 (C) [Fe 3 (H (CH 3 C) 6 ] (deep-red salt) boiling water (q) range precipitate (r) Reddish-brown precipitate (D) Ag 2 S 3 (white) boiling water (s) Red precipitate (t) Green 13 Match the products of reactions listed in column-i with their characteristic(s) listed in column-ii Column I Column II (A) HgI 2 I (excess) (B) Cr(H) 3 NaH (excess) (C) PbCr NaH (D) K 2 Zn 3 [Fe(CN) 6 ] 2 NaH (p) ne of the products is a colourless soluble complex (q) ne of the products is a coloured soluble complex (r) In one of the products the central atom or ion has tetrahedral geometry (s) ne of the products is a paramagnetic complex (t) ne of the product is a diamagnetic complex Ph () () QUALITATIVE ANALYSIS_ADVANCED # 21