JEE PYQ: Ionic Equilibrium Question 19
Question 19 - 2020 (09 Jan Shift 1)
Type: MCQ
The $K_{sp}$ for the following dissociation is $1.6 \times 10^{-5}$:
$\text{PbCl}2(s) \rightleftharpoons \text{Pb}^{2+}{(aq)} + 2\text{Cl}^-_{(aq)}$
Which of the following choices is correct for a mixture of 300 mL 0.134 M $\text{Pb(NO}_3)_2$ and 100 mL 0.4 M NaCl?
(a) Not enough data provided
(b) $Q < K_{sp}$
(c) $Q > K_{sp}$
(d) $Q = K_{sp}$
Show Answer
Answer: (b)
Solution
Given $K_{sp} = 1.6 \times 10^{-5}$
$[\text{Pb}^{2+}] = \frac{300 \times 0.134}{400} = 0.1005$
$[\text{Cl}^-] = \frac{100 \times 0.4}{400} = 0.1$
$Q = [\text{Pb}^{2+}][\text{Cl}^-]^2 = 0.1005 \times (0.1)^2 = 1.005 \times 10^{-3}$
$Q > K_{sp}$
BETA
