Ionic Equilibrium PYQs Set 2 (PDF)

Set 2 of 10 · Questions 31-60 of 274

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Ionic Equilibrium · Set 2 (Q31-60)
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31. $Which acid among the following has the highest p K_{a} value?$ (1) $HCl$ (2) $HF$ (3) $HI$ (4) $HBr$ 32. $Which salt from following forms aqueous solution having pH less than 7 ?$ (1) $CH_{3} COONa$ (2) $Na_{2} SO_{4}$ (3) $CuSO_{4}$ (4) $Na_{2} CO_{3}$ 33. $For the formation of NH_{3} (g) from its constituent elements, the favourable conditions for its formation are$ (1) $high pressure and low temperature$ (2) $high pressure and high temperature$ (3) $low pressure and high temperature$ (4) $low pressure and low temperature$ 34. $Given below are two statements one is labelled as Assertion A and the other is labelled as Reason R: Assertion A : The amphoteric nature of water is explained by using Lewis acid/base concept. Reason R : Water acts as an acid with N H_{3} and as a base with H_{2} S. In the light of the above statements choose the correct answer from the options given below$ (1) $Both A and R are true and R is the correct explanation of A.$ (2) $Both A and R are true but R is NOT the correct explanation of A.$ (3) $A is true but R is false.$ (4) $A is false but R is true.$ 35. $Observe the following solutions (i) 1 L of 10^{- 6} MAg NO_{3} (ii) 1 L of 10^{- 7} M AgNO_{3} (iii) 1 L of 10^{- 9} MAg NO_{3} (iv) 1 L of 10^{- 3} M AgNO_{3} (v) 1 L of 10^{- 5} MNaCl Which of the above two solutions when mixed will give a white precipitate, AgCl ? (Given K_{sp} of AgCl = 1 \times 10^{- 10})$ (1) $(i), (v)$ (2) $(ii), (v)$ (3) $(iv), (v)$ (4) $(iii), (v)$ 36. $For a reaction A (g) + \frac{1}{2} B (g) ⇌ C (g) + heat favorable conditions for the reaction to occur in the forward direction are$ (1) $Low T and Low P$ (2) $Low T and high P$ (3) $High T and Low P$ (4) $High T and high P$ 37. $For the formation of ammonia from its constituent elements ( 1 mole of N_{2} and 3 moles of H_{2}) in a closed vessel of volume V (L), the value of K_{C} is [units of (K_{C} = mol^{- 2} L^{2})$ (1) $\frac{3 x ^{2} V ^{2}}{9 ( 1 - x ) ^{4}}$ (2) $\frac{4 x V ^{2}}{9 ( 1 - x ) ^{3}}$ (3) $\frac{4 x ^{2} V ^{2}}{27 ( 1 - x ) ^{4}}$ (4) $\frac{x ^{2} V ^{2}}{27 ( 1 - x ) ^{3}}$ 38. $If K_{sp} of Ag_{2} CO_{3} is 8 \times 10^{- 12} the molar solubility of Ag_{2} CO_{3} in 0.1 MAgNO_{3} is:$ (1) $8 \times 10^{- 12} M$ (2) $8 \times 10^{- 11} M$ (3) $8 \times 10^{- 10} M$ (4) $8 \times 10^{- 13} M$ 39. $Which of the following does not form a buffer solution?$ (1) $NH_{3} + HCl (2:1 mole ratio)$ (2) $CH_{3} CO_{2} H + NaOH (2:1 mole ratio)$ (3) $NaOH + CH_{3} COOH (1:1 mole ratio)$ (4) $NH_{4} Cl + NH_{3} (1:1 mole ratio)$ 40. $Buffer solutions have constant acidity and alkalinity because$ (1) $these give unionised acid or base on reaction with added acid or alkali$ (2) $acids and alkalies in these solutions are shielded from attack by other ions$ (3) $they have large excess of H^{+} or O H^{-} ions$ (4) $they have fixed value of pH .$ 41. $Calculate dissociation constant of 0.001 M weak monoacidic base undergoing 2 % dissociation.$ (1) $4 \times 10^{- 7}$ (2) $2 \times 10^{- 6}$ (3) $2 \times 10^{- 7}$ (4) $1 \times 10^{- 7}$ 42. $One mole of A (g) is heated to T (K) till the following equilibrium is obtained A (g) ⇌ T (K) B (g) The equilibrium constant of this reaction is 10^{- 1} . After reaching the equilibrium, 0.5 moles of A (g) is added and heated. The equilibrium is again established. The value of \frac{[ A ]}{[ B ]} is$ (1) $10^{- 1}$ (2) $10$ (3) $10^{- 2}$ (4) $100$ 43. $The pH of pure water at 80^{\circ} C is$ (1) $7.0$ (2) $\infty$ (3) $> 7.0$ (4) $< 7.0$ 44. $If the value of equilibrium constant for a particular reaction is 1. 6 \times 1 0^{12}, then at equilibrium the system will contain$ (1) $mostly products$ (2) $similar amounts of reactants and products$ (3) $all reactants$ (4) $mostly reactants.$ 45. $If solubility product of Zr_{3} (PO_{4})_{4} is denoted by K_{sp} and its molar solubility is denoted by S, then which of the following relation between S and K_{Sp} is correct?$ (1) $S = (\frac{K _{sp}}{144})^{1/6}$ (2) $S = (\frac{K _{sp}}{6912})^{1/7}$ (3) $S = (\frac{K _{sp}}{929})^{1/9}$ (4) $S = (\frac{K _{sp}}{216})^{1/7}$ 46. $Aqueous solutions of H N O_{3}, KOH, C H_{3} COOH and C H_{3} COONa of identical concentrations are provided. The pair(s) of solutions which form a buffer upon mixing is (are)$ (1) $H N O_{3} and C H_{3} COOH$ (2) $KOH and C H_{3} COONa$ (3) $H N O_{3} and C H_{3} COONa$ (4) $C H_{3} COOH and C H_{3} COONa$ 47. $Which of the following gas has the highest pH at 25^{\circ} C ?$ (1) $Distilled H_{2} O$ (2) $1 M aq NH_{3}$ (3) $1 MNaOH$ (4) $1 MHCl$ 48. $At 1000 K, the value of K_{c} for the below reaction is 10 molL L^{- 1} . Value of K_{p} (in atm) is A (g) ⇌ B (g) + C (g) (given R = 0.082 atm L mol^{- 1} K^{- 1})$ (1) $82$ (2) $0.82$ (3) $8.2$ (4) $820$ 49. $20 mL of 0.1 M H_{2} S O_{4} solution is added to 30 mL of 0.2 M N H_{4} OH solution. The pH of the resultant mixture is: (p K_{b} of N H_{4} OH = 4.7)$ (1) $9.0$ (2) $5.2$ (3) $9.4$ (4) $5.0$ 50. $Observe the following species AlCl_{3}, NH_{3}, H^{+}, Co^{3 +}, - OH, Mg^{2 +}, BF_{3}, Cl^{-} How many Lewis acids are present in the above list?$ (1) $5$ (2) $4$ (3) $2$ (4) $3$ 51. $The equilibrium concentrations of the species in the reaction A + B ⇌ C + D are 2, 3, 10 and 6 mol L^{- 1} respectively at 300 K . Δ G^{0} for the reaction is (R = 2 cal / mol K)$ (1) $-13.73 cal$ (2) $1372.60 cal$ (3) $-137.26 cal$ (4) $-1381.80 cal$ 52. $If the p K_{a} of acetic acid and p K_{b} of dimethylamine are 4.76 and 3.26 respectively, the pH of dimethyl ammonium acetate solution is$ (1) $7.75$ (2) $6.75$ (3) $7.0$ (4) $8.5$ 53. $For a reversible reaction, if the concentration of the reactants is reduced to half, the equilibrium constant will be ______$ (1) $doubled$ (2) $halved$ (3) $reduced to one-fourth$ (4) $remains same$ 54. $Identify the correct expression for the equilibrium constant of the following reaction. 2 X (g) + Y (g) ⇌ 3 Z (g)$ (1) $k = \frac{[ X ] ^{2} [ Y ]}{[ Z ] ^{3}}$ (2) $k = \frac{[ Z ] ^{3}}{[ X ] ^{2} [ Y ]}$ (3) $k = \frac{3 [ Z ]}{2 [ X ] [ Y ]}$ (4) $k = [Z]^{3} [X]^{2} [Y]$ 55. $The first and second ionization constants of H_{2} X are 2.5 \times 10^{- 8} and 1.0 \times 10^{- 13} respectively. The concentration of X^{2 -} in 0.1 MH_{2} X solution is____\times 10^{- 15} M . (Nearest Integer)$ 56. $If the solubility product of AB_{2} is 3.20 \times 10^{- 11} M^{3}, then the solubility of A B_{2} in pure water is \times 10^{- 4} molL^{- 1} . [Assuming that neither kind of ion reacts with water]$ 57. $An analyst wants to convert 1 L HC1 of pH = 1 to a solution of HC1 of pH = 2. The volume of water needed to do this dilution is_____mL. (Nearest integer)$ 58. $If 1 mM solution of ethylamine produces pH = 9, then the ionization constant (K_{b}) of ethylamine is 10^{- x} . The value of x is (nearest integer). [The degree of ionization of ethylamine can be neglected with respect to unity.]$ 59. $The logarithm of equilibrium constant for the reaction P d^{2 +} + 4 C l^{-} ⇌ PdC l_{4}^{2 -} is ______(Nearest integer) Given : \frac{2.303 RT}{F} = 0.06V F P d_{(aq)}^{2 +} + 2 e^{-} ⇌ Pd (s) E^{0} = 0.83 V PdC l_{4}^{2 -} (aq) + 2 e^{-} ⇌ Pd (s) + 4 C l^{-} (aq)$ 60. $3 gram of acetic acid is mixed in 250 mL of 0.1 M HCl. This mixture is now diluted to 500 mL∙20mL of this solution is now taken in another container. \frac{1}{2} mL of 5M NaOH is added to this. Find the pH of this solution. (log 3 = 0.4771, p K_{a} = 4.74) . Multiply your answer with 100.$