Salt Analysis and Qualitative Analysis Exercise # 2

Exercise # 2 1. Part # I [Multiple Correct Choice Type Questions] Cu2+ ions give white precipitate with : (A) potassium iodide solution. (C) excess potassium cyanide solution. (B) potassium thiocyanate and saturated solution of SO2. (D) potassium hydroxide solution. 2. Which of the following statements is/are true ? (A) Ag+ ions do not give white precipitate with excess of concentrated HCl. (B) Cu2+ ions produce a white precipitate when KCN solution is added in a small quantity. (C) Hg2+ ions give deep blue precipitate with cobalt acetate and ammonium thiocyanate. (D) Black precipitate of BiI3 turns orange when heated with water. 3. K solution is the reagent for : (A) Hg2+ (B) Pb2+ (C) Ag+ (D) Cu2+ 4. Na2SO4 and Na2S can be distinguished from each other by using : (A) dilute H2SO4 (B) acidified KMnO4 solution (C) sodium nitroprusside solution (D) cadmium acetate solution 5. Which of the following anion(s) evolve(s) reddish brown gas with concentrated H 2SO4? (A) Br– (B) NO3– (C) SO32– (D) – 6. Ammonium molybdate test is used for the estimation of : (A) PO43– (B) Mg2+ (C) As43– (D) CH3COO– Which of the following cations form(s) black precipitate(s) with H2S (g) ? (A) Cu2+ (B) Sb3+ (C) Pb2+ (D) Bi3+ Borax bead test is given by : (A) Co2+ (B) Zn2+ (D) Ni2+ 7. 8. (C) Cu2+ 9. Concentrated aqueous ammonia dissolve(s) which of the following completely ? (A) AgCl (B) AgBr (C) Ag2CrO4 (D) Ag 10. Which of the following is/are correct for potassium ferrocyanide ? (A) It gives a brown precipitate with Cu2+ ions. (B) It gives a white precipitate of mixed salt with Ca2+ ions. (C) It in excess gives a bluish white/white precipitate with Zn2+. (D) It develops a deep red colouration with Fe3+. 11. Consider the reactions shown below ; CrO42– (aq) H2SO4 (aq) AgNO3(aq) [X] precipitate Cr2O72–(aq) SO2/H+ [Y] aqueous solution. 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 Cr2O72– to [Y] is an redox reaction. SALT ANALYSIS AND QUALITATIVE ANALYSIS 12. boiled Hg2I2 (green)   products with H 2O 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 HgI2 is formed. (D) Mercury is obtained 13. Which of the following statement(s) is /are false ? (A) Fe3+ gives red precipitate with dimethyl glyoxime in alkaline solution. (B) Cu2+ 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) Ag2O does not dissolve in nitric acid and ammonia solution. 14. 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) Fe2+ ions give brown colour precipitate with [Fe(CN)6]3– ions solution. (D) Green precipitate of Cr(OH)3 is soluble in Na2O2. 15. 16. White precipitate of PbSO4 gets dissolved in : (A) concentrated H2SO4 on heating (C) (NH4)2CO3 (B) concentrated NaOH (D) dilute HNO3 What final product(s) is/are formed in the following series of reactions ? H O Concentrated borax solution + silver nitrate solution  Precipitate 2 Products (final) boiling (A) Ag3BO3 (B) Ag2O (C) H3BO3 (D) AgBO2 17. Which of the following sulphides do not dissolve in 50% HNO3 but dissolve in aquaregia ? (A) CoS (B) NiS (C) CuS (D) HgS 18. Which of the following statement(s) is/are correct with respect to bromide ions ? (A) KBr on heating with MnO2 and concentrated H2SO4 liberates Br2 and SO2 gases. (B) KBr on heating with concentrated H2SO4 liberates Br2 and SO2 gases. (C) KBr forms HBr with concentrated H3PO4. (D) KBr(s) liberates Br2 on gentle warming with concentrated H2SO4 and K2Cr2O7(s). 19. Select the incorrect statement(s). (A) Ammonium ions produce yellow colour solution with sodium hexanitrito-N-cobaltate (III). (B) Ammonia gas develops a brown colour on filter paper moistened with a solution of MnCl2 and H2O2. (C) Ammonium ions produce white precipitate with saturated sodium hydrogen tartrate solution. (D) Ammonium salts in presence of sodium hydroxide solution produces red precipitate with 4-nitrobenzene diazonium chloride reagent. 20. Original solution of salt or mixture should not be prepared in concentrated HNO3 because it : (A) is highly corrosive. (B) oxidises H2S to S in IInd group. (C) undergoes disproportionation reaction. (D) converts sulphide of Ba, Sr and Pb into insoluble sulphates. 21. Which of the following statement(s) is/are correct ? (A) Yellow precipitated of silver arsenite is soluble in both nitric acid and ammonia. (B) Potassium cyanide when added in very small quantity to copper sulphate solution, produces first yellow precipitate which quickly converts in to white precipitate. (C) Black precipitate of BiI3 turns orange on heating with water. (D) White precipitate of Bi(OH)3 turns yellowish brown, when boiled. 22. The following can be used to regulate the concentration of OH¯ ions for the scheme of basic radical analysis (III group). (A) NH4NO3 (B) NH4Cl (C) (NH4)2SO4 (D) (NH4)2CO3 23. Select the correct statement(s). (A) In group III, Fe3+ and Cr3+ can be differentiated by increasing NH4+ ion concentration (B) In Vth group, Na2CO3 is added to precipitate out only the carbonates of Ba2+, Sr2+ and Ca2+. (C) Like brown ring test, diphenylamine test is given only by salts containing NO3–. (D) Sodium chloride on heating with aqueous solution of K2Cr2O7 and concentrated H2SO4 produces deep red vapours. 24. Co2+ + KCN (not in excess)  precipitate. Select the correct statement(s) with respect to the precipitate. (A) It is yellow in colour. (B) It is reddish-brown in colour. (C) It dissolves in excess of the reagent forming a brown solution. (D) It is obtained when brown solution (option (C) is acidified with dilute HCl in the cold. 25. Potassium ferrocyanide is used for testing (A) Cu2+ and Zn2+ (B) Fe3+ and Ca2+ (C) Ag+ and Zn2+ (D) Th4+ and Cu2+ 26. Which of the following statements is/are correct ? (A) An aqueous solution of Co(II) thiocyanate (10% freshly prepared) and mercuric nitrate solution taken in equal volumes on stirring the wall of the vessel with a glass rod produce deep-blue precipitate. (B) White precipitate of Al(OH)3 is soluble in sodium hydroxide as well as in ammonia solution. (C) Green precipitate of Cr(OH)3 readily dissolves in excess of sodium hydroxide forming a green solution. (D) Chromium (III) salts give green coloured borax bead in both oxidising and reducing flame. 27. Which of the following statement(s) is/are not correct ? (A) Nickel salts give rosy red precipitate with dimethyl glyoxime in excess of NH4OH. (B) Fe (III) salts give red colour with potassium sulphocyanide. (C) In nitroprusside, the iron and NO exist as Fe(III) and NO. (D) Mn (II) salts give white precipitate with NaOH which turns brown on adding Br 2 water. 28. Which of the following will give the same colour in oxidising flame as well as in the reducing flame in borax bead test (when cold) ? (A) Chromium (B) Copper (C) Cobalt (D) Nickel 29. Ni + H2SO4 (hot and concentrated)  X(g). The liberated gas (select the correct statement) : (A) develops blue colour spots on the filter paper moistened with potassium iodate and starch solution. (B) turns acidified K2Cr2O7 solution green. (C) produces black precipitate with lead acetate solution. (D) reacts with Cl2 water to produce an acid which gives white fumes with ammonia. SALT ANALYSIS AND QUALITATIVE ANALYSIS 30. Which of the following imparts green/apple green colour to the Bunsen flame ? (A) Calcium chloride (B) Volatile boron trifluoride (C) Barium chloride (D) Ethyl borate 31. CoCl2 + KNO2 + CH3COOH  [X] + H2O + KCl + CH3COOK + NO (Unbalanced equation) (A) X is a yellow crystalline solid insoluble in water. (B) X is a green coloured compounds known as kinman's green. (C) IUPAC name of X is potassium hexanitrito –N– cobaltate (II) (D) The compound X is an inner orbital complex. Part # II [Assertion & Reason Type Questions] Each question has 5 choices (A), (B), (C), (D) and (E) out of which only one is correct. (A) Statement-1 is true, Statement-2 is true and Statement-2 is correct explanation for Statement-1 (B) Statement-1 is true, Statement-2 is true and Statement-2 is not correct explanation for Statement-1 (C) Statement-1 is true,Statement-2 is false (D) Statement-1 is false, Statement-2 is true (E) Both Statements are false 1. Statement-1 : A solution containing S2– ions gives purple / violet colour with sodium nitroprusside solution in alkaline medium. Statement-2 : Sodium sulphide gives black precipitate with silver nitrate solution. 2. Statement-1 : Baryta water becomes turbid on passing CO2 gas through it but turbidity becomes clear on passing more CO2 gas. Statement-2 : Carbonates give yellowish white precipitate with silver nitrate solution. The precipitate becomes yellow or brown on heating. 3. Statement-1 : White crystalline precipitate of silver sulphite dissolves, if sulphite ions are added in excess. Statement-2 : Sulphite ions decolourise the pink colour of acidified KMnO4. 4. Statement-1 : Acidified K2Cr2O7 solution becomes green when SO2 gas is passed through it. Statement-2 : This is an redox reaction. 5. Statement-1 : When H2S gas is passed into an aqueous solution of ZnCl2 , Zn2+ ions are completely precipitated as zinc sulphide Statement-2 : Zinc sulphide is soluble in solutions of caustic alkali as well as in dilute HCl. 6. Statement-1 : An original solution containing excess of Ni2+ ions gives a yellow coloured solution with potassium cyanide solution. Statement-2 : A solution of Ni2+ ions gives red precipitate with dimethylglyoxime solution just made alkaline with ammonia. 7. Statement-1 : V group basic radicals are precipitated as their carbonates by (NH4)2CO3 in presence of ammonia or ammonium chloride. Statement-2 : Aqueous ammonia maintains the pH of the solution basic. 8. Statement-1 : Nessler’s reagent gives a brown precipitate with aqueous ammonia as well as with ammonium salts. Statement-2 : Aqueous ammonia gives a brown precipitate with a solution of manganese (II) chloride and hydrogen peroxide. 9. Statement-1 : Cu2+ and Cd2+ ions form complexes with excess of potassium cyanide solution. Statement-2 : On passing H2S gas, complex [Cu(CN)4]3– is not effected but [Cd(CN)4]2– gives yellow precipitate. 10. Statement-1 : A solution of BiCl3 in concentrated HCl when diluted with water gives white precipitate. Statement-2 : BiCl3 forms insoluble BiO+Cl– when diluted with a large quantity of water. 11. Statement-1 : In dilute solution of strontium ions, yellow precipitate of SrCrO4 is formed with CrO42– ions. Statement-2 : The SrCrO4 precipitate is appreciably soluble in water, therefore, no precipitation occurs when water is taken in large quantity. 12. Statement-1 : White precipitate of Mg(OH)2 is insoluble in excess of sodium hydroxide but readily soluble in solution of ammonium salts. Statement-2 : Mg(OH)2 is very sparingly soluble in water. 13. Statement-1 : White precipitate of zinc phosphate is soluble in ammonia. Statement-2 : Zinc phosphate forms a soluble complex with ammonia. PART # II 1. B 2. B 3. B 4. B 5. E 6. B 7. B 8. B 9. B 10. A 11. D 12. B 13. A