Ionic Equilibrium PDF

Ionic Equilibrium Exercise - I INTRODUCTION OSTWALD'S DILUTION LAW 1. The formula weight of H2SO4 is 98. The weight 12. Degree of dissociation of 0.1 N CH3COOH is :- of the acid in 400mL of 0.1 M solution is:-...

Ionic Equilibrium Exercise - I INTRODUCTION OSTWALD'S DILUTION LAW 1. The formula weight of H2SO4 is 98. The weight 12. Degree of dissociation of 0.1 N CH3COOH is :- of the acid in 400mL of 0.1 M solution is:- (Dissociation constant = 1 × 10–5) (1) 2.45 g (2) 3.92 g (3) 4.90 g (4) 9.8 g (1) 10–5 (2) 10–4 (3) 10–3 (4) 10–2 2. Normality of 2M sulphuric acid is:- 13. The degree of dissociation of acetic acid is given by the expression  = 0.1 × C–1 (where (1) 2 N (2) 4N (3) N/2 (4) N/4 C = concentration of the acid) What is the pH 3. If pH = 3.31, then find out [H+] (Approx) of the solution :- (1) 3.39 × 10–4 (2) 5 × 10–4 (1) 1 (2) 2 (3) 3 (4) 4 (3) 3.0 × 10–3 (4) None 14. Ostwald's dilution law is not applicable for 4. If [OH–] = 5.0 × 10–5 M then pH will be :- strong electrolytes because:- (1) 5 - log 5 (2) 9 + log 5 (1) Strong electrolytes are completely ionised (3) log 5 - 5 (4) log 5 - 9 (2) Strong electrolytes are volatile 5. Basicity of H3PO3 and H3PO2 are respectively:- (3) Strong electrolytes are unstable (1) 1 and 2 (2) 2 and 3 (4) Strong electrolytes often contain metal ions (3) 3 and 2 (4) 2 and 1 15. The degree of ionisation of a compound 6. Find out pH of solution having 2 × 10–3 moles depends upon : of OH– ions in 2 litre solution :- (1) Size of the solute molecules (1) pH = 3 (2) pH = 3 + log2 (2) Nature of the solute molecules (3) pH = 3 – log2 (4) pH = 11 (3) Nature of the container taken 7. pH of tomato juice is 4.4. Then concentration (4) The amount of current passed of H3O+ will be :- 16. Find out Ka for 10–2 M HCN acid, having (1) 39 × 10–4 (2) 3.9 × 10–5 pOH = 10 :- (1) Ka = 10–4 (2) Ka = 10–2 (3) 3.9 × 10–4 (4) 3.9 × 105 (3) Ka = 10–5 (4) None of these 8. 8 g NaOH is dissolved in one litre of solution, 17. Which of the following will occur if a 1.0 M the molarity of the solution is:- solution of a weak acid is diluted to 0.01 M at (1) 0.2 M (2) 0.4 M (3) 0.02 M (4) 0.8 M constant temperature:- 9. The amount of acetic acid present in 100 mL (1) Percentage ionisation will increase of 0.1M solution is :- (2) [H+] will decrease to 0.01M (1) 0.30 g (2) 3.0 g (3) 0.60 g (4) None (3) Ka will increase 10. The number of milli equivalents of acid in (4) pH will decrease by 2 units 18. The extent of ionisation of weak electrolytes 100 mL of 0.5N HCl solution is:- increases :- (1) 50 (2) 100 (3) 25 (4) 200 (1) With the increase in concentration of 11. If the molar concentration of MgCl2 is solute 1.5 × 10–3 mol L–1, the concentration of (2) On decreasing the temp. of solution chloride ions in g ion L–1 is:- (3) On addition of excess of water to the (1) 3.0 × 10–3 (2) 6.0 × 10–3 solution (3) 0.3 × 10–3 (4) 0.6 × 10–6 (4) On stirring the solution vigorously  Digital www.allendigital.in [ 191 ]  NEET : Chemistry 19. If Ka of HCN = 4 × 10–10, then the pH of SALTS, TYPES OF SALT & CONJUGATE THEORY 2.5 × 10–1 molar HCN (aq) is:- 29. Which of the following is not an acidic salt :- (1) 4.2 (2) 4.7 (3) 0.47 (4) 5.0 (1) NaHSO4 (2) HCOONa 20. The molarity of nitrous acid solution at which (3) NaH2PO3 (4) None of these its pH becomes 2.(Ka = 4.5 × 10–4) :- 30. Which is a basic salt :– (1) 0.3333 (2) 0.4444 (1) MgCl2 (2) KCl (3) 0.6666 (4) 0.2222 (3) NaCl (4) Mg(OH)Cl EXPLANATION OF WATER 31. The process of neutralisation invariably 21. Ionic product of water will increase, if :- results in the production of :- (1) Decrease the pressure (1) H+ ions (2) Add H+ (2) OH— ions (3) Add OH– (3) Both H+ and OH— ions (4) Increase the temperature (4) Molecules of water 22. For water at 25° C, 2 × 10–7 moles per litre is 32. Which of the following is an acidic salt :- the correct answer for which one of the following (1) Na2S (2) Na2SO3 (1) [H+] + [OH–] (2) [H+]2 (3) NaHSO3 (4) Na2SO4 (3) [OH–]2 (4) [H+] – [OH–] 33. The mixed salt among the following is :- 23. At 25 C, the dissociation constant for pure 0 CH(OH)COONa water is given by :- (1) | (2) NaKSO4 CH(OH)COONa (1) (55.4 × 1014)-1 (2) 1 × 10–14 (3) CaCl2 (4) All 1×10 –14 (3) (4) None of these 18 HYDROLYSIS OF SALTS 24. Ionic product of water is equal to :- 34. At 900 C, the pH of 0.1M NaCl aqueous (1) Dissociation constant of water × [H2O] solution is:- (2) Dissociation constant of water × [H+] (1) < 7 (2) > 7 (3) 7 (4) 0.1 (3) Product of [H2O] and [H+] 35. What will be the pH of 1.0 M ammonium formate (4) Product of [OH–]2 and [H+] solution, If Ka=1 × 10–4 acid Kb =1× 10–5:- 25. For pure water, addition of H+ and OH– ion (1) 6.5 (2) 7.5 (3) 8.0 (4) 9.0 concentrations at 900C is :- 36. Which salt will not undergo hydrolysis :- (1) 10–14 (2) 10–12 (1) KCl (2) Na2SO4 (3) NaCl (4) All (3) 2 × 10 –6 (4) 2 × 10–7 37. HCOO– + H2O HCOOH + OH– 26. At a certain temperature, pure water has [H3O+] =10–6.7 mol L–1.What is the value of KW Degree of hydrolysis for above reaction is at this temperature :- given by:- (1) 10–6 (2) 10–12 Kh (1) h = K h (2) h = (3) 10 –67 (4) 10–13.4 C 27. At 373 K, temp. the pH of pure H2O can be:- Kh (1) < 7 (2) > 7 (3) = 7 (4) = 0 (3) h = (4) Kh = hc 28. Which of the following is a true statement : V (1) The ionisation constant and ionic product 38. The pH of aqueous solution of sodium acetate of water are same. is (2) Water is a strong electrolyte. (1) 7 (2) Very low (3) The value of ionic product of water is less (3) > 7 (4) < 7 than that of its ionisation constant. 39. If pKb for CN at 25 C is 4.7. The pH of 0.5M – o (4) At 298K, the number of H+ ions in a litre of aqueous NaCN solution is :- water is 6.023 × 1016. (1) 12 (2) 10 (3) 11.5 (4) 11 [ 192 ] www.allendigital.in  Digital  Ionic Equilibrium 40. The highest pH value is of :- 47. auea A salt 'X' is dissolved in water of pH = 7. (1) 0.1 M NaCl The resulting solution becomes alkaline in (2) 0.1 M NH4Cl nature. The salt is made up of:- (1) A strong acid and strong base (3) 0.1 M CH3COONa (2) A strong acid and weak base (4) 0.1 M CH3COONH4 (3) A weak acid and weak base 41. pH of K2S solution is:- (4) A weak acid and strong base (1) 7 (2) Less than 7 SOLUBILITY & SOLUBILITY PRODUCT (KSP) (3) More than 7 (4) 0 48. The solubility product of sparingly soluble 42. For anionic hydrolysis, pH is given by:- Uni- univalent salt (AB type) is defined as the 1 1 1 product of ionic concentration in a:- (1) pH = pKW – pKb – logC (1) 1 M solution 2 2 2 (2) Concentration solution 1 1 1 (3) Very dilute solution (2) pH = pKW + pKa – pKb 2 2 2 (4) Saturated solution 1 1 1 49. If solubility of salts M2X, QY2 and PZ2 are (3) pH = pKW + pKa + logC 2 2 2 equal, then the relation between their Ksp will (4) None of above be :- (1) Ksp(M2X) > Ksp (QY2) > Ksp (PZ2) 43. Ionisation constant of a weak acid is 10–4. (2) Ksp(M2X) = Ksp (QY2) < Ksp (PZ2) Find out equilibrium constant for the reaction (3) Ksp(M2X) > Ksp (QY2) = Ksp (PZ2) of this weak acid with strong base :- (4) Ksp(M2X) = Ksp (QY2) = Ksp (PZ2) (1) 10–10 (2) 1010 (3) 10–9 (4) 109 50. The expression of solubility product of 44. Hydroxyl ion concentration [OH—] in the case mercurous iodide is :- of sodium acetate can be expressed as (where (1) [2 Hg+]2 × 2 [I–]2 (2) [Hg++]2 × [ 2I–]2 2+ Ka is dissociation constant of CH3COOH and C (3) [ Hg 2 ] × [I–]2 (4) [Hg2+]2 × [I–]2 is the concentration of sodium acetate):- 51. At 250C, the Ksp value of AgCl is 1.8 × 10–10. If (1) [OH–] = (CKw. Ka)1/2 10–5 moles of Ag+ are added to solution then (2) [OH–] = C.Kw K a Ksp will be :- (1) 1.8 × 10–15 (2) 1.8 × 10–10 1/2  C.K w  (3) 1.8 × 10 –5 (4) 18 × 10+10 (3) [OH–] =  52. At 250C, the volume of water required to  Ka  dissolve 1g BaSO4 (Ksp = 1.0 × 10–10) will be (4) [OH–] = C. Ka. Kw. (Molecular weight of BaSO4 = 233) :- 45. Consider :- (1) 820 L. (2) 1 L. (3) 205 L. (4) 430 L. (a) FeCl3 in water - Basic 53. Concentration of Ag ions in saturated + (b) NH4Cl in water - Acidic solution of Ag2CrO4 at 200C is 1.5 × 10–4 mol (c) Ammonium acetate in water - Acidic L–1. At 200C, the solubility product of Ag2CrO4 (d) Na2CO3 in water - Basic is :- (1) 3.3750 × 10–12 (2) 1.6875 × 10–10 Which is/are not correctly matched:- (3) 1.68 × 10–12 (4) 1.6875 × 10–11 (1) b and d (2) b only 54. If the concentration of CrO42– ion in a (3) a and c (4) d only saturated solution of silver chromate will be 46. Which of the following salts undergoes 2 × 10–4 M, solubility product of silver hydrolysis in water:- chromate will be - (1) Na3PO4 (2) CH3COONa (1) 4 × 10–8 (2) 8 × 10–12 (3) NaNO3 (4) Both (1) and (2) (3) 32 × 10–12 (4) 6 × 10-12 ·  Digital www.allendigital.in [ 193 ]  NEET : Chemistry 55. If the solubility of AgCl (formula mass=143) 64. If the maximum concentration k of PbCl2inin in water at 25°C is 1.43 10–4 g/100 mL of water is 0.01 M at 298 K, its maximum solution then the value of Ksp will be :– concentration in 0.1 M NaCl will be:- (1) 1  10–5 (2) 2  10–5 (1) 4 × 10–3 M (2) 0.4 × 10–4 M (3) 4 × 10–2 M (4) 4 × 10–4 M (3) 1  10–10 (4) 2  10–10 65. M2SO4 (M+ is a monovalent metal ion) has a 56. The solubility product of As2S3 is given by the Ksp of 1.2 × 10–5 at 298 K. The maximum expression :- concentration of M+ ion that could be attained (1) Ksp = [As3+] [S–2] (2) Ksp = [As3+]1 [S–2]1 in a saturated solution of this solid at 298 K (3) Ksp = [As3+]3 [S–2]2 (4) Ksp = [As3+]2 [S–2]3 is:- 57. If the solubility of PbBr2 is 'S' g molecules per (1) 3.46 × 10–3 M (2) 2.89 × 10–2 M litre, considering 100% ionisation its (3) 2.8 × 10–3 M (4) 7.0 × 10–3 M solubility product is :- 66. Which of the following has maximum (1) 2S3 (2) 4S2 (3) 4S3 (4) 2S4 solubility 58. If the solubility of lithium sodium hexafluoro (Ksp value is given in brackets) :- aluminate Li3Na3(AlF6)2 is 'S' mol L–1. Its (1) HgS (1.6 × 10–54) (2) PbSO4 (1.3 × 10–8) solubility product is equal to :- (3) ZnS (7.0 × 10–26) (4) AgCl (1.7 × 10–10) (1) S8 (2) 12 S3 67. Maximum soluble is :- (Ksp is given) (3) 18S3 (4) 2916 S8 (1) CuS (8.5 × 10–36) (2) CdS (3.6 × 10–28) 59. One litre of saturated solution of CaCO3 is (3) ZnS (1.2 × 10–28) (4) MnS (1.4 × 10–10) evaporated to dryness, when 7.0 g of residue 68. In which of the following, the solubility of is left. The solubility product for CaCO3 is:- AgCl will be maximum :- (1) 4.9 × 10–3 (2) 4.9 × 10–5 (1) 0.1 M AgNO3 (2) Water (3) 4.9 × 10–9 (4) 4.9 × 10–7 (3) 0.1 M NaCl (4) 0.1 M KCl APPLICATION OF SOLUBILITY PRODUCT(KSP) 69. The solubility product of three sparingly 60. Solubility of AgBr will be minimum in :- soluble salts are given below : (1) Pure water (2) 0.1 M CaBr2 No. Formula Solubility product (3) 0.1 M NaBr (4) 0.1 M AgNO3 1 PQ 4.0 × 10–20 61. In which of the following, the solution of 2 PQ2 3.2 × 10–14 AgSCN will be unsaturated :- 3 PQ3 2.7 × 10–35 (1) [Ag+] [SCN–] = Ksp (2) [Ag+] [SCN–] < Ksp The correct order of decreasing molar (3) [Ag+] [SCN–] > Ksp (4) [Ag+] [SCN–]2 < Ksp solubility is:- 62. If 's' and 'S' are solubility and solubility (1) 1, 2, 3 (2) 2, 1, 3 product of a sparingly soluble binary (3) 3, 2, 1 (4) 2, 3, 1 electrolyte respectively then :– 70. The Ksp value for Gd(OH)3 is 2.8 × 10–23. Find (1) s = S (2) s = S2 the pH of saturated solution of Gd(OH)3 :- 1S (3) s = S1/2 (4) s = (1) 6.08 (2) 5.08 (3) 8.47 (4) 4.08 2 71. If the solubility product of AgBrO3 and Ag2SO4 63. The solubility product of CuS , Ag2S and HgS are 5.5 × 10–5 and 2 × 10–5 respectively, the are 10–37, 10–44 and 10–54 respectively. The relationship between their solubilities can be solubility of these sulphides will be in the correctly represented as :- order (1) SAgBrO3 > SAg2SO4 (2) SAgBrO3 = SAg2SO4 (1) HgS > Ag2S > CuS (2) Ag2S > HgS > CuS (3) CuS > Ag2S > HgS (4) Ag2S > CuS > HgS (3) SAgBrO3 < SAg2SO4 (4) Unpredictable [ 194 ] www.allendigital.in  Digital Ionic Equilibrium 72. Solubility product of Mg(OH)2 is 1 × 10–11. At FEW IMPORTANT POINTS what pH, precipitation of Mg(OH)2 will begin 77. Two monobasic weak acids have the same moles of H+ ions. What is the relationship from between dissociation constant and dilution:- 0.1 M Mg2+ solution :- (1) Ka1 V1 =Ka2 V2 (2) Ka1 V2 =Ka2 V1 (1) 9 (2) 5 (3) 3 (4) 7 1 1 73. A solution, containing 0.01 M Zn+2 and (3)  Ka1 V1  2 =Ka 2 V2 (4) Ka1 V1 =Ka2 V2  2 0.01 M Cu2+ is saturated by passing H2S gas. 78. Two solutions having same concentration of The S–2 concentration is 8.1 × 10–21 M, Ksp for H+ ions are called:- ZnS and CuS are 3.0 × 10–22 and 8.0 × 10–36 (1) Isotonic solutions respectively. Which of the following will (2) Isohydric solutions occur in the solution:- (3) Hypotonic solutions (1) ZnS will precipitate (4) Hypertonic solutions 79. The pH of a 0.1 M formic acid 0.1% (2) CuS will precipitate dissociated is equal to 4. What will be the pH (3) Both ZnS and CuS will precipitate of another weak monobasic acid (same (4) Both Zn2+ and Cu2+ will remain in the concentration) which is 1% dissociated solution (1) 2 (2) 3 (3) 1 (4) 4 74. What will happen if the pH of the solution of PH 0.001 M Mg(NO3)2 solution is adjusted to pH = 80. pH of water is 7. When any substance Y is 9 dissolved in water then pH becomes 13. (KspMg(OH)2 = 8.9 × 10-12) Substance Y is a salt of :- (1) Precipitation will take place (1) Strong acid and strong base (2) Precipitation will not take place (2) Weak acid and weak base (3) Solution will be saturated (3) Strong acid and weak base (4) None of these (4) Weak acid and strong base 81. Minimum pH is shown by aqueous solution 75. The solubility product constant Ksp of of:- Mg(OH)2 is 9.0 × 10–12. If a solution is 0.010 (1) 0.1 M BaCl2 (2) 0.1 M Ba(NO3)2 M with respect to Mg2+ ion, what is the (3) 0.1 M BeCl2 (4) 0.1 M Ba(OH)2 maximum hydroxide ion concentration which 82. Given :- could be present without causing the (a) 0.005 M H2SO4 (b) 0.1 M Na2SO4 precipitation of Mg(OH)2 :- (c) 10–2 M NaOH (d) 0.01 M HCl (1) 1.5 × 10–7 M (2) 3.0 × 10–7 M Choose the correct code having same pH :- (3) 1.5 × 10–5 M (4) 3.0 × 10–5 M (1) a, c, d (2) b, d 76. When HCl gas is passed through a saturated (3) a, d (4) a, c 83. What is H+ ion concentration of 5 × 10–3 M solution of common salt, pure NaCl is H2CO3 solution having a 10% dissociation:- precipitated because:- (1) 10–3 (2) 10–2 (1) The impurities dissolve in HCl (3) 10–1 (4) 5 × 10–2 (2) HCl is slightly soluble in water 84. A metal hydroxide of molecular formula (3) The ionic product [Na+] × [Cl–] exceeds the M(OH)4 is 50% ionised. Its 0.0025M solution solubility product of NaCl will have the pH :- (4) The solubility product of NaCl is lowered (1) 12 (2) 2 by Cl– from aq. HCl (3) 4 (4) 11.7 -  Digital www.allendigital.in [ 195 ]  NEET : Chemistry 85. In the following solutions, the conc. of 95. The pOH of a solution is 10.0. hydrogen The hydrogen different acids are given, which mixture of the ion concentration will be :– acid has highest pH :- Kw Kw (a) 10–10 (b) –10 (c) (d) 10–4 M M M 10 10 –8 (1) H2SO4, HNO3, HClO4 10 20 10 (1) a, d (2) b, c (3) a, b, c (4) None M M M 96. An aqueous solution whose pH = 0 is :- (2) H2SO4, HNO3, HClO4 20 10 20 (1) Basic (2) Acidic M M M (3) Neutral (4) Amphoteric (3) H2SO4, HNO3, HClO4 20 10 40 97. Following five solution of KOH were prepare M M M as– (4) H2SO4, HNO3, HClO4 First → 0.1 moles in 1 L 20 5 5 Second → 0.2 moles in 2 L 86. If 100 mL of pH = 3 and 400 mL of pH = 3 Third → 0.3 moles in 3 L solutions are mixed, what will be the final pH Fourth → 0.4 moles in 4 L of mixture Fifth → 0.5 moles in 5 L (1) 3.2 (2) 3.0 (3) 3.5 (4) 2.8 The pH of resultant solution is :– 87. 10 M HCl is diluted 100 times. Its pH is :- –6 (1) 2 (2) 1 (3) 13 (4) 7 (1) 6.0 (2) 8.0 (3) 6.95 (4) 9.5 98. The pH of a 0.02 M ammonia solution which 88. pH of 0.001M acetic acid would be :- is 5% ionised will be :- (1) 2 (2) > 3 (3) 7 (4) 14 (1) 2 (2) 11 (3) 5 (4) 7 89. At 90°C, the pH of 0.001M KOH solution will be N 99. For H2SO4, pH value is :- (1) 3 (2) 11 (3) 5 (4) 9 10 90. The pH of solution is increased from 3 to 6. Its (1) 1 (2) 0.586 (3) 0.856 (4) None H+ ion concentration will be :- 100. An aqueous solution of HCl is 10–9 M HCl. The (1) Reduced to half pH of the solution should be:- (2) Doubled (1) 9 (2) Between 6 and 7 (3) Reduced by 1000 times (3) 7 (4) Unpredictable (4) Increased by 1000 times 101. How many moles of HCl must be removed 91. A solution has pOH equal to 13 at 298 K. The from 1 litre of aqueous HCl solution to change solution will be:- its pH from 2 to 3 :- (1) 1 (2) 0.02 (3) 0.009 (4) 0.01 (1) Highly acidic (2) Highly basic 102. 8 g NaOH and 4.9 g H2SO4 are present in one (3) Moderately basic (4) Unpredictable litre of the solution. What is its pH 92. The pH of the solution containing 10 mL of a (1) 1 (2) 13 (3) 12 (4) 2 0.1M NaOH and 10 mL of 0.05M H2SO4 would be 103. Calculate pH of a solution whose 100 mL (1) Zero (2) 1 (3) >7 (4) 7 contains 0.2 g NaOH dissolved in it :- 93. In a solution of pH = 5, more acid is added in (1) 10.699 (2) 11.699 (3) 12.699 (4) 13.699 order to reduce the pH upto 2. The increase in 104. What is the quantity of NaOH present in 250 hydrogen ion concentration is:- cc of the solution, so that it gives a pH = 13 :- (1) 100 times (2) 1000 times (1) 10–13 g (2) 10–1 g (3) 1.0 g (4) 4.0 g (3) 3 times (4) 5 times 105. 0.001 mol of the strong electrolyte M(OH)2 has 94. The hydrogen ion concentration in a given been dissolved to make a 20 mL of its saturated solution is 6 × 10–4 M. Its pH will be :- solution. Its pH will be : - [Kw = 1 × 10–14] (1) 6 (2) 3.22 (3) 4 (4) 2. (1) 13 (2) 3.3 (3) 11 (4) 9.8 - [ 196 ] www.allendigital.in  Digital Ionic Equilibrium 106. Choose the wrong statement :- & 113. What is the suitable indicator for titration titration ofof (1) For a neutral solution : [H+] = [OH–] = NaOH and oxalic acid:- Kw (1) Methyl orange (2) Methyl red (2) For an acidic solution : (3) Phenolphthalein (4) Starch solution [H+] > K w & [OH–] < Kw 114. Phenolphthalein does not act as an indicator for the titration between :- (3) For a basic solution : (1) KOH and H2SO4 [H+] < K w & [OH–] > Kw (2) NaOH and CH3COOH (4) For a neutral solution : (3) Oxalic acid and KMnO4 [H+] = [OH–] = 10–7 M (at all temperatures) (4) Ba(OH)2 and HCl 107. The pH of 0.1 M solution of the following salts 115. Which can act as buffer :- increases in order :- (1) NH4OH + NaOH (1) NaCl < NH4Cl < NaCN < HCl (2) HCOOH + CH3COONa (2) NaCN < NH4Cl < NaCl < HCl (3) 40 mL 0.1 M NaCN + 20 mL of 0.1 M HCl (3) HCl < NaCl < NaCN < NH4Cl (4) None of them (4) HCl < NH4Cl < NaCl < NaCN 116. The buffer solution play an important role in:- BUFFER SOLUTIONS AND INDICATOR 108. In a buffer solution the ratio of concentration (1) Increasing the pH value of NH4Cl and NH4OH is 1 : 1. When it changes (2) Decreasing the pH value to 2 : 1, pH of buffer :- (3) Keeping the pH constant (1) Increases (2) Decreases (4) Solution will be neutral (3) No effect (4) None of these 117. Ka for HCN is 5 x 10–10 at 250C. For 109. To 50 mL of 0.05M formic acid, how much maintaining a constant pH of 9, the volume of volume of 0.10M sodium formate must be 5M KCN solution required to be added to added to get a buffer solution of pH = 4.0 ? 10mL of 2M HCN solution is- (pKa of the acid is 3.8) (1) 4 mL (2) 7.95 mL (1) 50 mL (2) 4 mL (3) 2 mL (4) 9.3 mL (3) 39.6 mL (4) 100 mL 118. Buffering action of a mixture of CH3COOH and 110. In the volumetric estimation of HCl, if we CH3COONa is maximum when the ratio of salt make use of phenolphthalein as an indicator, to acid is equal to - which base is unsuitable for the titration :- (1) 1.0 (2) 100.0 (3) 10.0 (4) 0.1 (1) NaOH (2) RbOH 119 The pink colour of phenolphthalein in (3) KOH (4) NH4OH alkaline medium is due to - 111. In a mixture of weak acid and its salt, the ratio (1) Negative ion (2) Positive ion of concentration of acid to salt is increased (3) OH ions – (4) Neutral form ten-fold. The pH of the solution :- 120. Which indicator works in the pH range 8 – 9.8 (1) Decreases by one (1) Phenolphthalein (2) Methyl orange (2) Increases by one-tenth (3) Methyl red (4) Litmus (3) Increases by one 121. A basic buffer will obey the equation (4) Increases ten-fold pOH – pKb = 1 only under condition:- 112. pKb for NH4OH at certain temperature is 4.74. (1) [Conjugate acid] : [base] = 1 : 10 The pH of basic buffer containing equimolar (2) [Conjugate acid] = [base] concentration of NH4OH and NH4Cl will be:- (3) [Conjugate acid] : [base] = 10 : 1 (1) 7.74 (2) 4.74 (3) 2.37 (4) 9.26 (4) None of these  Digital www.allendigital.in [ 197 ]  NEET : Chemistry 122. For weak acid-strong base titration, the 130. On addition of NaOH to CH3COOH solutionsolution, indicator used is :- 60% of the acid is neutralised. If pKa of (1) Potassium dichromate CH3COOH is 4.7 then the pH of the resulting (2) Methyl orange solution is :- (3) Litmus (1) More than 4.7 but less than 5.0 (4) Phenolphthalein (2) Less than 4.7 but more than 4.0 123. For which of the following titration, methyl (3) More than 5.0 orange is a best indicator :- (4) Remains unchanged (1) CH3COOH + NaOH 131. 500 mL of 0.2 M acetic acid are added to 500 mL (2) H2C2O4 + NaOH of 0.30 M sodium acetate solution. If the (3) HCl + NaOH dissociation constant of acetic acid is 1.5 × 10–5 (4) CH3COOH + NH4OH then pH of the resulting solution is:- 124. The total number of different kind of buffers (1) 5.0 (2) 9.0 (3) 3.0 (4) 4.0 obtained during the titration of H3PO4 with 132. Half of the formic acid solution is neutralised NaOH are :- on addition of a KOH solution to it. If (1) 3 (2) 1 (3) 2 (4) 0 Ka (HCOOH) = 2 × 10–4 then pH of the solution 125. A certain acidic buffer solution contains equal is : (log 2 = 0.3010) concentration of X– and HX. The Kb for X– is (1) 3.6990 (2) 10.3010 10–10. The pH of the buffer is :- (3) 3.85 (4) 4.3010 (1) 4 (2) 7 (3) 10 (4) 14 133. A solution contains 0.2M NH4OH and 126. When 1.0 mL of dil. HCl acid is added to 0.2M NH4Cl. If 1.0 mL of 0.001 M HCl is added to it. What will be the [OH–] of the resulting 100 mL of a buffer solution of pH 4.0. The pH solution of the solution [Kb = 2 × 10–5] :- (1) Becomes 7 (2) Does not change (1) 2 × 10–5 (2) 5 × 10–10 (3) Becomes 2 (4) Becomes 10 (3) 2 × 10–3 (4) None of these 127. The pH of blood is maintained by CO2 and 134. Henderson equation pH – pKa = 1 will be H2CO3 in the body and chemical constituents applicable to an acidic buffer when :- of blood. This phenomenon is called :- (1) [Acid] = [Conjugate base] (1) Colloidal (2) Buffer action (2) [Acid] × 10 = [Conjugate base] (3) Acidity (4) Salt balance (3) [Acid] = [Conjugate base] × 10 128. Phenolphthalein is not a good indicator for (4) None of these titrating 135. 0.05 M ammonium hydroxide solution is (1) NaOH against oxalic acid dissolved in 0.001 M ammonium chloride (2) NaOH against HCl solution. What will be the OH– ion (3) NaOH against H2SO4 concentration of this solution: Kb(NH4OH) = (4) HCl against NH4OH 1.8 × 10–5 129. Which of the following solutions does not act (1) 3.0 × 10–3 (2) 9.0 × 10–4 as buffer :– (3) 9.0 × 10 –3 (4) 3.0 × 10–4 (1) H3PO4 + NaH2PO4 136. When 0.02 moles of NaOH are added to a litre (2) NaHCO3 + H2CO3 of buffer solution, its pH changes from 5.75 to (3) NH4Cl + HCl 5.80. What is its buffer capacity :- - (4) CH3COOH + CH3COONa (1) 0.4 (2) 0.05 (3) –0.05 (4) 2.5 [ 198 ] www.allendigital.in  Digital  Ionic Equilibrium 137. Calculate the pH of a buffer prepared by > - 144. Select the species which can function as lewis Lewis mixing 300 cc of 0.3 M NH3 and 500 cc of 0.5 base, bronsted acid and bronsted base:- M NH4Cl. Kb for NH3 = 1.8 × 10–5 :- (a) H2O + (b) NH4 (c) N–3 (1) 8.1187 (2) 9.8117 Correct code is :- (3) 8.8117 (4) None of these (1) Only a (2) a, b (3) a, c (4) b, c 138. Calculate the ratio of pH of a solution 145. Which ion does not show acid behaviour :- containing 1 mole of CH3COONa + 1 mole of +3 +3 HCl per litre and of other solution containing (1)  Al ( H2O )6  (2) Fe ( H2O )6      1 mole CH3COONa + 1mole of acetic acid per (3) HPO4–2 (4) ClO3– litre :- 146. An example of Lewis acid is:- (1) 1 : 1 (2) 2 : 1 (3) 1 : 2 (4) 2 : 3 (1) CaO (2) CH3NH2 M (3) SO3 (4) None of these 139. When 20 mL of NaOH are added to 10 mL 20 147. In the reaction NH3 + H2O NH4+ + OH– M water behaves as :- of HCl, the resulting solution will:- 10 (1) Acid (2) Base (1) Turn blue litmus red (3) Neutral (4) Both acid & Base (2) Turn phenolphthalein solution 148. Which acts as Lewis base in the reaction (3) Turn methyl orange red BCl3 + :PH3 → Cl3B  PH3 (4) Will have no effect on either red or blue (1) PH3 (2) BCl3 litmus (3) Both 1 & 2 (4) None 140. 10 mL of a solution contains 0.1 M NH4Cl + 0.01 M 149. Which acts as Lewis acid in the reaction NH4OH. Which addition would not change the SnCl2 + 2Cl– ⎯⎯→ [SnCl4]–2 pH of solution :– (1) Cl– (2) SnCl2 (3) SnCl4 (4) None + (1) Adding 1 mL water 150. The conjugate base of (CH3)2 NH2 is :- (2) Adding 5 mL of 0.1 M NH4Cl (1) CH3NH2 (2) (CH3)2N+ (3) Adding 5 mL of 0.1 M NH4OH (3) (CH3)2N (4) (CH3)2NH (4) Adding 10 mL of 0.1 M NH4Cl 151. Which equilibrium can be described as Lewis N N acid base reaction but not Bronsted acid base 141. acetic acid was titrated with NaOH. 10 10 reaction:- When 25%, 50% and 75% of titration is over (1) H2O + CH3COOH H3O+ + CH3COO– then the pH of solution will be :- [Ka = 10–5] (1) 5 + log 1/3, 5, 5 + log 3 (2) 2NH3 + H2SO4 2NH4+ + SO24− (2) 5 + log 3, 4, 5 + log 1/3 (3) NH3 + CH3COOH NH4+ + CH3COO– (3) 5 – log 1/3, 5, 5 – log 3 (4) 5 – log 1/3, 4, 5 + log 1/3 (4) Cu+2 + 4NH3 [Cu(NH3)4]2+ ACID AND BASE 152. Conjugate base of hydrazoic acid is :- − 142. The conjugate acid of O–2 is :- (1) HN3− (2) N3− (3) N3– (4) N2 (1) O2+ (2) H+ (3) H3O+ (4) OH– 153. NH3 gas dissolves in water to give NH4OH, in 143. Ionization constant of AOH and BOH base are this reaction, water acts as :- K b1 and K b2. Their relation is pK b 1 < pK b 2. (1) An acid (2) A base (3) A salt (4) A conjugate base Conjugate of following base, does not show 154. When ammonia is added to water, it maximum pH : decreases the concentration of which of the (1) AOH (2) BOH following ion (3) Both of them (4) None of these (1) OH– (2) H3O+ (3) NH+4 (4) None -  Digital www.allendigital.in [ 199 ]  NEET : Chemistry 155. The strongest acid among the following is - n 166. The conjugate base for bicarbonate ion is:- (1) ClO3(OH) (2) ClO2(OH) (1) CO32– (2) HCO3– (3) SO(OH)2 (4) SO2(OH)2 (3) CO2 (4) H2CO3 156. Which of the following is not a Bronsted acid:- 167. HCl does not behave as acid in :- (1) CH3NH4+ (2) CH3COO– (1) NH3 (2) C2H5OH (3) H2O (4) HSO4– (3) H2O (4) C6H6 157. Which of the following example behave as a 168. Which of the following is a base according to Lewis acid BF3, SnCl2, SnCl4 :- Bronsted-Lowry concept :- (1) SnCl2, SnCl4 (2) BF3, SnCl2 (1) I– (2) H3O+ (3) HCl (4) NH4+ (3) Only BF3 (4) BF3, SnCl2, SnCl4 158. In the reaction 169. In which of the following reactions NH3 acts as acid HNO3 + H2O H3O+ + NO3–, the conjugate (1) NH3 + HCl → NH4Cl base of HNO3 is :- (2) NH3 + H+ → NH4+ (1) H2O (2) H3O+ (3) NO3– (4) H3O+ and NO3– 1 (3) NH3 + Na → NaNH2 + H2 159. The conjugate base of the weak acid in the 2 (4) NH3 cannot act as acid reaction HBr + H2O H3O+ + Br– is 170. According to Bronsted concept, the acids in the (1) HBr (2) H2O (3) Br– (4) H3O+ 160. In the reaction, AlCl3 + Cl– → [AlCl4]–, AlCl3 following reaction NH3 + H2O NH4+ + OH– acts as :- are :- (1) Salt (2) Lewis base (1) NH3 and NH4+ (2) H2O and OH– (3) Bronsted acid (4) Lewis acid (3) H2O and NH4+ (4) NH3 and OH– 161. Mg is _______ than Al :- 2+ 3+ 171. CH3COO– ion is a :- (1) Stronger Lewis acid (1) Weak conjugate base (2) Stronger Lewis base (2) Strong conjugate base (3) Weaker Lewis acid (3) Weak conjugate acid (4) Weaker Lewis base (4) Strong conjugate acid 162. The two Bronsted bases in the reaction 172. Which of the following is strongest conjugate HC2O4– + PO43– HPO42– + C2O42– are base (1) HC2O4– and PO42– (2) HPO42– and C2O42– (1) ClO4– (2) HCO3– (3) Cl– (4) HSO4– (3) PO43– and C2O4–2 (4) HC2O4– and HPO42– 173. Which of the following species can act as 163. The compound HCl behaves as ---- in the Lewis base :- reaction, HCl + HF H2+Cl + F– (1) Cu2+ (2) AlCl3 (3) NH3 (4) BF3 (1) Strong acid (2) Strong base 174. A compound having the formula (3) Weak acid (4) Weak base NH2CH2COOH may behave :- 164. Which of the following is not a lewis base:- (1) Only as an acid (1) NH3 (2) O2– (3) H2O (4) I+ (2) Only as a base 165. Which of the following is Bronsted Lowry acid:- (3) Both as an acid and base (1) SO4–2 (2) H3O+ (3) OH– (4) Cl– (4) Neither acid nor base [ 200 ] www.allendigital.in  Digital Ionic Equilibrium 175. Which of the following can act both as rect 182. Which of the following is not a correct Bronsted acid and Bronsted base :- statement (1) Na2CO3 (2) O2– (1) Arrhenius theory of acids-bases is capable (3) CO3–2 (4) NH3 of explaining the acidic or basic nature of 176. The strongest conjugate base is :- the substances in the solvents other than − water (1) NO 3 (2) Cl– (2) Arrhenius theory does not explain acidic 2− (3) SO4 (4) CH3COO– nature of AlCl3 177. Aluminium chloride is :- (3) The aqueous solution of Na2CO3 is alkaline (1) Bronsted Lowry acid although it does not contain OH– ions (2) Arrhenius acid (4) Aqueous solution of CO2 is acidic although (3) Lewis acid it does not contain H+ ions + (4) Lewis base 183. For the reaction NH 4 + S–2 NH3 + HS–,NH3 178. Water is a :- and S–2 are a group of :- (1) Protogenic solvent (1) Acids (2) Bases (2) Protophilic solvent (3) Acid-base pair (4) None of these (3) Amphiprotic solvent 184. According to Arrhenius theory, acids are (4) Aprotic solvent substances that dissociate in water to 179. Ammonium ion is :- give...(X)... ions and bases are substances that (1) A conjugate acid produce...(Y).... ions. Here, (X) and (Y) refer to (2) A conjugate base (1) Hydronium, Hydroxyl (3) Neither an acid nor a base (2) Hydroxyl, Hydrogen (3) Hydrogen, Hydroxyl (4) Both an acid and a base (4) Hydroxyl, Hydronium 180. Species which do not act both as Bronsted 185. ‘An acid is substance that is capable of acid and base is :- donating a proton (H+) and base is a (1) (HSO4)–1 (2) Na2CO3 substance capable of accepting a proton (H+). (3) NH3 (4) OH–1 The above statement is justified by 181. Which one of the following is strong Lewis (1) Arrhenius concept base & Bronsted acid & bronsted base:- (2) Bronsted-Lowry theory (1) NH3 (2) PH3 (3) Lewis concept (3) CH4 (4) BH3 (4) All of these  Digital www.allendigital.in [ 201 ]  NEET : Chemistry EXERCISE-I (Conceptual Questions) ANSWER KEY Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Answer 2 2 2 2 4 4 2 1 3 1 1 4 1 1 2 Question 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Answer 4 1 3 4 4 4 1 1 1 3 4 1 4 2 4 Question 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 Answer 4 3 2 1 1 4 2 3 3 3 3 3 2 3 3 Question 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Answer 4 4 4 4 3 2 4 3 3 3 4 3 4 1 2 Question 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 Answer 2 3 4 4 2 2 4 2 4 3 3 1 2 2 4 Question 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 Answer 3 2 2 2 4 3 3 1 4 3 2 3 2 4 3 Question 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 Answer 1 4 2 2 4 2 3 2 1 2 3 2 3 3 1 Question 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 Answer 4 4 2 3 4 1 4 3 3 3 3 3 1 1 1 Question 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 Answer 3 4 3 1 1 2 2 4 3 1 1 1 1 2 2 Question 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 Answer 1 3 3 4 1 1 4 2 1 4 3 1 1 2 4 Question 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 Answer 4 2 1 2 1 2 4 3 2 4 3 3 4 4 2 Question 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 Answer 1 4 1 3 3 2 2 3 3 4 4 3 3 1 2 Question 181 182 183 184 185 Answer 1 1 2 3 2 [ 202 ] www.allendigital.in  Digital  Ionic Equilibrium Exercise - II (Previous Year Questions) AIPMT 2009 7. A buffer solution is prepared in which the 1. The ionization constant of ammonium concentration of NH3 is 0.30 M and the hydroxide is 1.77 × 10–5 at 298 K. Hydrolysis concentration of NH4+ is 0.20 M. If the constant of ammonium chloride is :- equilibrium constant, Kb for NH3 equals (1) 5.65 × 10–12 (2) 5.65 × 10–10 1.8 × 10–5, what is the pH of this solution ? (3) 6.50 × 10–12 (4) 5.65 × 10–13 (log 2.7 = 0.43) 2. What is the [OH ] in the final solution – (1) 9.08 (2) 9.43 (3) 11.72 (4) 8.73 prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10M Ba(OH)2 ? AIPMT Mains 2012 (1) 0.12 M (2) 0.10 M 8. Buffer solutions have constant acidity and (3) 0.40 M (4) 0.0050M alkalinity because: 3. The dissociation constants for acetic acid and (1) They have large excess of H+ or OH– ions HCN at 25°C are 1.5 × 10–5 and 4.5 × 10–10, (2) They have fixed value of pH respectively. The equilibrium constant for the (3) These give unionised acid or base on equilibrium reaction with added acid or alkali CN– + CH3COOH HCN + CH3COO– (4) Acids and alkalies in these solutions are would be :- shielded from attack by other ions (1) 3.3 × 104 (2) 3.0 × 105 9. Equimolar solutions of the following (3) 3.3 × 10–5 (4) 3.0 × 10–4 substances were prepared separately. Which AIPMT 2010 one of the these will record the highest pH 4. If pH of a saturated solution of Ba(OH)2 is 12, value? the value of its Ksp is :- (1) LiCl (2) BeCl2 (3) BaCl2 (4) AlCl3 (1) 5.00 × 10–7 M3 (2) 4.00 × 10–6 M3 NEET UG 2013 (3) 4.00 × 10–7 M3 (4) 5.00 × 10–6 M3 10. Which is the strongest acid in the following ? 5. Find the pH of a buffer solution containing equal (1) H2SO3 (2) H2SO4 concentration of B– and HB. (Kb for B– is 10–10) :- (3) HClO3 (4) HClO4 (1) 4 (2) 10 (3) 7 (4) 6 AIPMT Mains 2011 AIPMT 2014 6. In qualitative analysis, the metals of Group I can 11. Which of the following salts will give highest be separated from other ions by precipitating pH in water ? them as chloride salts. A solution initially (1) KCl (2) NaCl contains Ag+ and Pb2+ at a concentration of 0.10 (3) Na2CO3 (4) CuSO4 M. Aqueous HCl is added to this solution until AIPMT 2015 the Cl– concentration is 0.10 M. What will the 12. The Ksp of Ag2CrO4, AgCl, AgBr and AgI are concentrations of Ag+ and Pb2+ be at respectively, 1.1 × 10–12, 1.8 × 10–10, 5.0 × 10–13, equilibrium? 8.3 × 10–17. Which one of the following salts (Ksp for AgCl=1.8 × 10–10, Ksp for PbCl2=1.7 × 10–5) will precipitate last if AgNO3 solution is added (1) [Ag+] = 1.8 × 10–11 M ; [Pb2+] = 1.7 × 10–4 M; to the solution containing equal moles of NaCl, (2) [Ag+] = 1.8 × 10–7 M ; [Pb2+] = 1.7 × 10–6 M; NaBr, NaI and Na2CrO4 ? (3) [Ag+] = 1.8 × 10–11 M ; [Pb2+] = 8.5 × 10–5 M; (1) AgCl (2) AgBr (4) [Ag+] = 1.8 × 10–9 M ; [Pb2+] = 1.7 × 10–3 M; (3) Ag2CrO4 (4) AgI -  Digital www.allendigital.in [ 203 ]  NEET : Chemistry Re-AIPMT 2015 NEET(UG) 2017 13. Which one of the following pairs of solution is 18. Concentration of the Ag+ ions in a saturated not an acidic buffer ? solution of Ag2C2O4 is 2.2 × 10–4 mol L–1 (1) H2CO3 and Na2CO3 Solubility product of Ag2C2O4 is :- (1) 2.66 × 10–12 (2) 4.5 × 10–11 (2) H3PO4 and Na3PO4 (3) 5.3 × 10–12 (4) 2.42 × 10–8 (3) HClO4 and NaClO4 (4) CH3COOH and CH3COONa NEET(UG) 2018 14. What is the pH of the resulting solution when 19. Following solutions were prepared by mixing equal volumes of 0.1 M NaOH and 0.01 M HCl different volumes of NaOH and HCl of are mixed? different concentrations : M M (1) 7.0 (2) 1.04 (3) 12.65 (4) 2.0 a. 60mL HCl + 40mL NaOH 10 10 M M NEET-I 2016 b. 55mL HCl + 45mL NaOH 10 10 15. MY and NY3, two nearly insoluble salts, have M M the same Ksp values of 6.2 × 10–13 at room c. 75mL HCl + 25mL NaOH 5 5 temperature. Which statement would be true M M in regard to MY and NY3 ? d. 100mL HCl + 100mL NaOH 10 10 (1) The molar solubilities of MY and NY3 in pH of which one of them will be equal to 1 ? water are identical. (1) b (2) a (3) d (4) c (2) The molar solubility of MY in water is less 20. The solubility of BaSO4 in water 2.42 × 10–3 gL–1 than that of NY3 at 298 K. The value of solubility product (Ksp) will (3) The salts MY and NY3 are more soluble in be (Given molar mass of BaSO4 = 233 g mol–1) 0.5 M KY than in pure water. (1) 1.08 × 10–10 mol2 L–2 (4) The addition of the salt of KY to solution of (2) 1.08 × 10–12 mol2 L–2 (3) 1.08 × 10–14 mol2 L–2 MY and NY3 will have no effect on their (4) 1.08 × 10–8 mol2 L–2 solubilities. NEET(UG) 2019 NEET-II 2016 21. pH of a saturated solution of Ca(OH)2 is 9. 16. The percentage of pyridine (C5H5N) that The solubility product (Ksp) of Ca(OH)2 is :- forms pyridinium ion (C5H5N+H) in a 0.10 M (1) 0.5 × 10–15 (2) 0.25 × 10–10 (3) 0.125 × 10–15 (4) 0.5 × 10–10 aqueous pyridine solution (Kb for C5H5N = 1.7 22. Which will make basic buffer ? × 10–9) is (1) 50 mL of 0.1 M NaOH + 25 mL of 0.1 M (1) 0.77% (2) 1.6% CH3COOH (3) 0.0060% (4) 0.013% (2) 100 mL of 0.1 M CH3COOH + 100 mL of 17. The solubility of AgCl(s) with solubility 0.1M NaOH product (3) 100 mL of 0.1 M HCl + 200 mL of 0.1 M 1.6 × 10–10 in 0.1 M NaCl solution would be NH4OH (1) 1.6 × 10–11 M (2) zero (4) 100 mL of 0.1 M HCl + 100 mL of 0.1 M (3) 1.26 × 10–5 M (4) 1.6 × 10–9 M NaOH [ 204 ] www.allendigital.in  Digital Ionic Equilibrium NEET(UG) (Odisha) 2019 28. o The solubility product for a salt of the type AB AB 23. The pH of 0.01 M NaOH (aq) solution will be is 4 × 10. What is the molarity of its standard –8 (1) 7.01 (2) 2 (3) 12 (4) 9 solution? 24. Which of the following cannot act both as (1) 2 × 10–4 mol/L (2) 16 × 10–16 mol/L (3) 2 × 10–16 mol/L (4) 4 × 10–4 mol/L Bronsted acid and as Bronsted base ? (1) HCO3– (2) NH3 (3) HCl (4) HSO4– NEET (UG) 2021 25. The molar solubility of CaF2 (Ksp = 5.3 × 10–11) 29. The pKb of dimethylamine and pKa of acetic in 0.1 M solution of NaF will be acid are 3.27 and 4.77 respectively at T (K). (1) 5.3 × 10–11 mol L–1 (2) 5.3 × 10–8 mol L–1 The correct option for the pH of (3) 5.3 × 10–9 mol L–1 (4) 5.3 × 10–10 mol L–1 dimethylammonium acetate solution is: (1) 8.50 (2) 5.50 NEET (UG) 2020 (3) 7.75 (4) 6.25 26. Find out the solubility of Ni(OH)2 in 0.1M NaOH. NEET (UG) 2022 Given that the ionic product of Ni(OH)2 is 30. The pH of the solution containing 50 mL each 2 × 10–15. of 0.10 M sodium acetate and 0.01 M acetic (1) 1 × 108 M (2) 2 × 10–13 M acid is [Given pKa of CH3COOH = 4.57] (3) 2 × 10–8 M (4) 1 × 10–13 M (1) 3.57 (2) 4.57 NEET (UG) 2020 (COVID-19) (3) 2.57 (4) 5.57 27. Which among the following salt solutions is 31. 0.01 M acetic acid solution is 1% ionised, then basic in nature ? pH of this acetic acid solution is : (1) Ammonium chloride (1) 3 (2) 2 (3) 4 (4)1 (2) Ammonium sulphate (3) Ammonium nitrate (4) Sodium acetate EXERCISE-II (Previous Year Questions) ANSWER KEY Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Answer 2 2 1 1 1 4 2 3 3 4 3 3 3 3 2 Question 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Answer 4 4 3 4 1 1 3 3 3 3 2 4 1 3 4 Question 31 Answer 3  Digital www.allendigital.in [ 205 ]  NEET : Chemistry Exercise – III (Analytical Questions) 1. Given below are two statements: 3. Given below are two statements: Statement-I : During hydrolysis of Statement-I : When NaCl is dissolved in CH3COONH4, the ions formed undergo water then electrostatic interactions are hydrolysis as follow : reduced by a factor 80. Statement-II : Dielectric constant of water is 80. CH3COO– + NH4+ + H2O CH3COOH + NH4OH In the light of the above statements, choose Statement-II : The degree of hydrolysis of the most appropriate answer from the CH3COONH4 is independent of concentration options given below: of solution. (1) Statement-I and statement-II are incorrect. In the light of the above statements, choose (2) Statement-I and statement-II are correct. the most appropriate answer from the (3) Statement-I is incorrect but statement-II is correct. options given below: (4) Statement-I is correct but statement-II is (1) Statement-I & statement-II both are correct incorrect (2) Only statement-I is correct 4. Arrange the following solutions in the (3) Only statement-II is correct decreasing order of pH : (4) Statement-I & statement-II both are (A) 0.01 M HCl incorrect (B) 0.01 M NaOH 2. Match the following : (C) 0.01 M CH3COONa pH calculation for following mixtures can be (D) 0.01 M NaCl done on the basis of concept of (1) (B) > (D) > (C) > (A) List-I List-II (2) (B) > (C) > (D) > (A) (a) Buffer (i) 50 mL of 0.1 M HCl (3) (A) > (C) < (D) > (B) solution mixed with 10 mL of (4) (A) > (D) > (C) > (B) 0.2 M HCN. 5. 100 mL of 0.1 M HCl is taken in a beaker and to it (b) Salt (ii) 200 mL of 0.02 M 100 mL of 0.1 M NaOH is added in steps of 2 mL hydrolysis CH3COONa mixed and the pH is continuously measured. Which of with 100 mL 0.02 M the following graphs correctly depicts the CH3COOH change in pH? (c) Strong acid (iii) 100 mL of 0.5 M HCl mixed with 500 mL of 0.1 M NH4OH (1) (d) Weak acid (iv) 100 mL of 0.4 M NaCN mixed with 100 mL of 0.4 M HCl (1) (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i) (2) (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i) (2) (3) (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv) (4) (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv) [ 206 ] www.allendigital.in  Digital Ionic Equilibrium hoose In the light of the above statements, choose the most appropriate answer from the (3) options given below: (1) Statement-I and statement-II are incorrect. (2) Statement-I and statement-II are correct. (3) Statement-I is incorrect but statement-II is correct. (4) (4) Statement-I is correct but statement-II is incorrect 9. Given below are two statements: Statement-I : The cations of strong bases and 6. Given below are two statements: anions of strong acids simply get hydrolyse Statement-I : Solubility of AgBr decreases in but do not get hydrated. the presence of NaBr. Statement-II : The solutions of salts formed Statement-II : NaBr undergoes hydrolysis in from strong acids & bases are neutral. water. In the light of the above statements, choose In the light of the above statements, choose the most appropriate answer from the the most appropriate answer from the options given below: options given below: (1) Statement-I and statement-II are incorrect. (2) Statement-I and statement-II are correct. (1) Statement-I and statement-II are incorrect. (3) Statement-I is incorrect but statement-II (2) Statement-I and statement-II are correct. is correct. (3) Statement-I is incorrect but statement-II (4) Statement-I is correct but statement-II is is correct. incorrect (4) Statement-I is correct but statement-II is 10. Given below are two statements; one is incorrect labelled as Assertion (A) and the other is 7. Statement-I : Acids turn red litmus paper blue. labelled as Reason(R). Statement-II : Acids taste bitter and feel soapy. Assertion : Addition of acetate ions to an (1) Statement-I and statement-II are incorrect. acetic acid solution results in decreasing the (2) Statement-I and statement-II are correct. concentration of hydrogen ions. (3) Statement-I is incorrect but statement-II Reason : Due to common ion effect, the is correct. equilibrium moves in the direction of (4) Statement-I is correct but statement-II is undissociated acetic acid. In the light of the above statements, choose incorrect the most appropriate answer from the 8. Given below are two statements: options given below : Statement-I : Conjugate acid and conjugate (1) (A) is correct but (R) is not correct base of NH3 respectively are NH4+ and NH2—. (2) Both (A) and (R) are correct and (R) is Statement-II : The acid base pair that differs correct explanation of (A) only by one proton is called a conjugate acid (3) Both (A) and (R) are correct but (R) is not base pair. correct explanation of (A) (4) (A) is not correct but (R) is correct &  Digital www.allendigital.in [ 207 ]  NEET : Chemistry 11. Given below are two statements; one is 14. > - If concentrations of two acids are same, their labelled as Assertion (A) and the other is relative strengths can be compared by : labelled as Reason(R).  [H+ ] (a) 1 (b) + 1 Assertion : All Arrhenius acids are Bronsted 2 [H ]2 acids. K1 K1 Reason : All Bronsted acids are Arrhenius (c) (d) K2 K2 acids. In the light of the above statements, choose (1) a, c, d are correct (2) a, b, c are correct the most appropriate answer from the (3) b, c, d are correct (4) All are correct options given below : 15. Which can act as a buffer ? (a) CH3COOH + NaOH; if [CH3COOH] > [NaOH] (1) (A) is correct but (R) is not correct (b) HCl + CH3COONa; if [CH3COONa] > [HCl] (2) Both (A) and (R) are correct and (R) is (c) HCl + NaCl correct explanation of (A) (d) NH4CN (3) Both (A) and (R) are correct but (R) is not (1) a, b, d (2) b, c, d (3) a, c, d (4) c, d correct explanation of (A) 16. Given below are two statements: (4) (A) is not correct but (R) is correct Statement-I: For HCN, pKa (HCN) + pKb (CN¯) = pkw 12. Match the Column – I and Column - II at all temperature. Column-I Column-II Statement-II : Sum of negative log of ionisation (Species) (Conjugate acid) constants of weak acid and of it’s conjugate base (a) NH3 (p) H2CO3 is equal to 14 at all temperatures. (b) HCO3– (q) H2SO4 In the light of the above statements, choose (c) H2O (r) NH4+ the most appropriate answer from the (d) HSO4– (s) H3O+ options given below: (1) (a) → (r); (b) → (p); (c) → (s); (d) → (q) (1) Statement-I and statement-II are incorrect. (2) (a) → (p); (b) → (r); (c) → (q); (d) → (s) (2) Statement-I and statement-II are correct. (3) (a) → (r); (b) → (s); (c) → (p); (d) → (q) (3) Statement-I is incorrect but statement-II is correct. (4) (a) → (q); (b) → (p); (c) → (r); (d) → (s) (4) Statement-I is correct but statement-II is 13. Match the Column – I and Column - II incorrect Column-I Column-II 17. Given below are two statements: (a) Al(OH)3  K sp  1/7 (p) Statement-I : pH of a 1.0 × 10–8 M solution of S=   6912  HCl is 8 at 25°C. (b) BaCrO4 1/3 Statement-II : HCl is a strong acid and  K sp  (q) S=  negative log of H+ concentration is called pH.  4  In the light of the above statements, choose (c) Zr3 (PO4)4  K sp  1/4 (r) the most appropriate answer from the S=   27  options given below: (d) Hg2 I2 (s) S = (Ksp)1/2 (1) Statement-I and statement-II are incorrect. (1) (a) → (r); (b) → (s); (c) → (p); (d) → (q) (2) Statement-I and statement-II are correct. (3) Statement-I is incorrect but statement-II (2) (a) → (s); (b) → (p); (c) → (r); (d) → (q) is correct. (3) (a) → (p); (b) → (q); (c)→ (s); (d) → (r) (4) Statement-I is correct but statement-II is (4) (a) → (q); (b) → (r); (c) → (p); (d) → (s) incorrect = [ 208 ] www.allendigital.in  Digital Ionic Equilibrium 18. Given below are two statements; one is 19. Given below are two statements; one is labelled as Assertion (A) and the other is labelled as Assertion (A) and the other is labelled as Reason(R). labelled as Reason(R). Assertion : pH of NH4Cl solution in water is Assertion : Water act as base in the reaction less than 7 at 25°C. HCl (aq.) + H2O() H3O+(aq.) + Cl¯(aq.) Reason : Ammonium hydroxide is a strong base. Reason : According to Bronsted-lowry In the light of the above statements, choose proton acceptors are known as base. the most appropriate answer from the In the light of the above statements, choose options given below : the most appropriate answer from the (1) (A) is correct but (R) is not correct (2) Both (A) and (R) are correct and (R) is options given below : correct explanation of (A) (1) (A) is correct but (R) is not correct (3) Both (A) and (R) are correct but (R) is not (2) Both (A) and (R) are correct and (R) is correct explanation of (A) correct explanation of (A) (4) (A) is not correct but (R) is correct (3) Both (A) and (R) are correct but (R) is not 20. Amongs H2O, HCO3¯, HSO4¯ and NH3 the correct explanation of (A) species which can act as Bronsted acid as well as Bronsted bases, are – (4) (A) is not correct but (R) is correct (1) H2O and NH3 (2) H2O, HCO3¯, HSO4¯ (3) NH3, HCO3¯, HSO4¯ (4) H2O, HCO3¯, HSO4¯, NH3 EXERCISE-III (Analytical Questions) ANSWER KEY Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Answer 1 4 2 2 1 4 1 2 3 2 1 1 1 2 1 Question 16 17 18 19 20 Answer 4 3 2 1 4  Digital www.allendigital.in [ 209 ]