Ionic Equilibrium PYQs Set 6 (PDF)

Set 6 of 10 · Questions 151-180 of 274

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Ionic Equilibrium · Set 6 (Q151-180)
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151. $Find out the solubility of Ni (OH)_{2} in 0.1 M NaOH. Given that the ionic product of Ni (OH)_{2} is 2 \times 10^{- 15} .$ (1) $2 \times 10^{- 8} M$ (2) $1 \times 10^{- 13} M$ (3) $1 \times 10^{8} M$ (4) $2 \times 10^{- 13} M$ 152. $Standard entropies of X_{2}, Y_{2} and X Y_{3} are 60,40 and 50 JK^{- 1} mol^{- 1} respectively. At what temperature, the following reaction will be at equilibrium? [given : Δ H^{\circ} = - 30 kJ] \frac{1}{2} X_{2} + \frac{3}{2} Y_{2} ⇌ X Y_{3}$ (1) $500 K$ (2) $750 K$ (3) $1000 K$ (4) $1250 K$ 153. $Which among the following denotes the correct relationship between K_{p} and K_{c} for the reaction, 2 A (g) ⇌ B (g) + C (g)$ (1) $K_{p} > K_{c}$ (2) $K_{c} > K_{p}$ (3) $K_{c} = (K_{p})^{2}$ (4) $K_{p} = K_{c}$ 154. $A solution is prepared by mixing 10 mL of 1.0 M acetic acid and 20 mL of 0.5 M sodium acetate and diluted to 100 mL . If the pK_{a} of acetic acid is 4.76 , then the pH of the solution is$ (1) $4.76$ (2) $3.76$ (3) $5.76$ (4) $9.24$ 155. $pH of a saturated solution of Ca (OH_{2}) is 9. The solubility product (K_{sp}) of Ca (OH)_{2} is:$ (1) $0.5 \times 10^{- 15}$ (2) $0.25 \times 10^{- 10}$ (3) $0.125 \times 10^{- 15}$ (4) $0.5 \times 10^{- 10}$ 156. $The compound whose water solution has the highest p H is$ (1) $N a C l$ (2) $N a H C O_{3}$ (3) $N a_{2} C O_{3}$ (4) $N H_{4} C I$ 157. $Observe the following solutions I. Black coffee II. 0.2 MNaOH III. Lemon juice IV. Lime water V. Human Saliva VI. Tomato juice The number of solutions with pH less than 7 is$ (1) $2$ (2) $5$ (3) $4$ (4) $3$ 158. $Which one of the following pairs of solution is not an acidic buffer?$ (1) $C H_{3} C O O H and C H_{3} C O O N a$ (2) $H_{2} C O_{3} and N a_{2} C O_{3}$ (3) $H_{3} P O_{4} and N a_{3} P O_{4}$ (4) $H C l O_{4} and N a C l O_{4}$ 159. $The solubility product of PbCl_{2} at 298 K is 3.2 \times 10^{- 5} . What is it's solubility in mol dm^{- 3} ?$ (1) $8 \times 10^{- 6}$ (2) $2 \times 10^{- 2}$ (3) $5.6 \times 10^{- 3}$ (4) $5.0 \times 10^{- 2}$ 160. $Arrange the following solutions in the decreasing order of pH (A) 0.01 MHCl (B) 0.01 MNaOH (C) 0.01 MCH_{3} COONa (D) 0.01 MNaCl$ (1) $(B) > (C) > (D) > (A)$ (2) $(A) > (D) > (C) > (B)$ (3) $(A) > (C) > (D) > (B)$ (4) $(B) > (D) > (C) > (A)$ 161. $Find solubility of PbI_{2} if it's solubility product is 7.0 \times 10^{- 9} .$ (1) $1.21 \times 10^{- 3} mol L^{- 1}$ (2) $3.228 \times 10^{- 3} mol L^{- 1}$ (3) $2.831 \times 10^{- 3} mol L^{- 1}$ (4) $1.811 \times 10^{- 3} mol L^{- 1}$ 162. $Calculate the value of the equilibrium constant (K_{P}) for the reaction of oxygen gas oxidising ammonia gas to nitric oxide and water vapour. The pressure of each gas at equilibrium is 0.5 atm .$ (1) $1.5 atm$ (2) $0.5 atm$ (3) $1 atm$ (4) $2.5 atm$ 163. $For the following Assertion and Reason, the correct option is Assertion (A) : When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid. Reason (R) : The equilibrium constant of Cu2+aq+S2-aq⇌CuSsis: high because the solubility product is low.$ (1) $(A) is false and (R) is true.$ (2) $Both (A) and (R) are true but (R) is not the explanation for (A).$ (3) $Both (A) and (R) are true and (R) is the explanation for (A).$ (4) $Both (A) and (R) are false.$ 164. $Given below are two statements : Statement (I) : Aqueous solution of ammonium carbonate is basic. Statement (II) : Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on K_{a} and K_{b} value of acid and the base forming it. In the light of the above statements, choose the most appropriate answer from the options given below :$ (1) $Both Statement I and Statement II are correct$ (2) $Statement I is correct but Statement II is incorrect$ (3) $Both Statement I and Statement II are incorrect$ (4) $Statement I is incorrect but Statement II is correct$ 165. $Aqueous solution of which of the following compounds is the best conductor of electric current?$ (1) $Hydrochloric acid, HCl$ (2) $Ammonia, N H_{3}$ (3) $Fructose,$ (4) $Acetic acid, C_{2} H_{4} O_{2}$ 166. $At T (K) when one mol of X and one mol of Y are heated in a 1 L flask, 0.5 moles of Z is formed at the equilibrium. The K_{c} value for the reaction is X (g) + Y (g) ⇌ Z (g) + A (g)$ (1) $0.5$ (2) $1.0$ (3) $0.75$ (4) $0.82$ 167. $What is the pH of millimolar solution of NaOH ?$ (1) $13$ (2) $11$ (3) $3$ (4) $12$ 168. $In some solutions, the concentration of H_{3} O^{+} remains constant even when small amounts of strong acid or strong base are added to them. These solutions are known as:$ (1) $Ideal solutions$ (2) $Colloideal solutins$ (3) $true solutions$ (4) $Buffer solutions$ 169. $An alkali is titrated against an acid with methyl orange as indictor, which of the following is a correct combination? Base Acid End point$ (1) $Weak Strong Yellow to pinkish red$ (2) $Strong Strong Pink to colourless$ (3) $Weak Strong Colourless to pink$ (4) $Strong Strong Pinkish red to yellow$ 170. $p K_{a} of a weak acid (HA) and p K_{b} of a weak base (BOH) are 3.2 and 3.4, respectively. The pH of their salt (AB) solution is :$ (1) $6.9$ (2) $7.0$ (3) $1.0$ (4) $7.2$ 171. $The p K_{a} of a weak acid (HA) is 4.5. The pOH of an aqueous buffered solution of HA, in which 50% of the acid is ionized, is :$ (1) $9.5$ (2) $7.0$ (3) $4.5$ (4) $2.5$ 172. $If equal volumes of A B_{2} and XY (both are salts) aqueous solutions are mixed, which of the following combination will give a precipitate of AY_{2} at 300 K? (Given K_{sp} (at 300 K) for AY_{2} = 5.2 \times 10^{- 7})$ (1) $2.0 \times 10^{- 4} MAB_{2}, 0.8 \times 10^{- 3} MXY$ (2) $2.0 \times 10^{- 2} MAB_{2}, 2.0 \times 10^{- 2} MXY$ (3) $1.5 \times 10^{- 4} MAB_{2}, 1.5 \times 10^{- 3} MXY$ (4) $3.6 \times 10^{- 3} MAB_{2}, 5.0 \times 10^{- 4} MXY$ 173. $Solubility of calcium phosphate (molecular mass, M) in water is W_{g} per 100 mL at 25^{\circ} C . Its solubility product at 25^{\circ} C will be approximately.$ (1) $10^{7} (\frac{W}{M})^{3}$ (2) $10^{7} (\frac{W}{M})^{5}$ (3) $10^{3} (\frac{W}{M})^{5}$ (4) $10^{5} (\frac{W}{M})^{5}$ 174. $For a reaction, 2 A \to B + C, K_{c} is 2 \times 10^{- 3} . At a given time, the reaction mixture has [A] = [B] = [C] = 3 \times 10^{- 4} M. Which of the following options is correct?$ (1) $The system is at equilibrium$ (2) $The reaction proceeds to the left$ (3) $The reaction proceeds to the right$ (4) $The reaction is complete$ 175. $The formation of ammonia from its constituent elements is an exothermic reaction. The effect of increase temperature on the reaction equilibrium is$ (1) $The rate of the forward reaction becomes zero$ (2) $No effect of temperature.$ (3) $Forward reaction is favored$ (4) $Backward reaction is favored$ 176. $For ammonia formation from constituent elements, the expression for K_{C} is$ (1) $K_{C} = \frac{( NH _{3} ) ^{3}}{( N _{2} ) ^{3} ( H _{2} ) ^{3}}$ (2) $K_{C} = \frac{( NH _{3} ) ^{2}}{( N _{2} ) ( H _{2} ) ^{3}}$ (3) $K_{C} = \frac{( NH _{3} )}{( N _{2} ) ( H _{2} )}$ (4) $K_{C} = (NH_{3})^{2}$ 177. $If K_{1} and K_{2} are the respective equilibrium constants for the two reactions, X e F_{6 (g)} + H_{2} O_{(g)} \to X e O F_{4 (g)} + 2 H F_{(g)} X e O_{4 (g)} + X e F_{6 (g)} \to X e O F_{4 (g)} + X e O_{3} F_{2 (g)}, the equilibrium constant of the reaction, X e O_{4 (g)} + 2 H F_{(g)} \to X e O_{3} F_{2 (g)} + H_{2} O_{(g)}, will be$ (1) $K_{1} / K_{2}$ (2) $K_{1} \cdot K_{2}$ (3) $K_{1} / (K_{2})^{2}$ (4) $K_{2} / K_{1}$ 178. $40 mL of a mixture of CH_{3} COOH and HCl (aqueous solution) is titrated against 0.1 M NaOH solution conductometrically. Which of the following statement is correct?$ (1) $The concentration of CH_{3} COOH in the original mixture is 0.005 M$ (2) $The concentration of HCl in the original mixture is 0.005 M$ (3) $CH_{3} COOH is neutralised first followed by neutralisation of HCl$ (4) $Point 'C' indicates the complete neutralization of HCl$ 179. $Calculate the pO H of asolution at 2 5^{0} C that contains 1 \times 1 0^{- 10} M ofhydronium ions, i.e. H_{3} O^{+}$ (1) $4.000$ (2) $9.000$ (3) $1.000$ (4) $7.000$ 180. $The dissociation constant of acetic is x x 1 0^{- 5}, When 25 mL of 0.2 M C H_{3} COONa solution is mixed with 25 mL of 0.02 M C H_{3} COOH solution, the pH of the resultant solution is found to be equal to 5. The value of x is$