Question

The solubility product of a sparingly soluble salt $ AX_2 $ is $ 3.2 \times 10^{-11} $ . Its solubility (in mol/L) is

• A. $ 5.6 \times 10^{-6} $
• B. $ 3.1 \times 10^{-4} $
• C. $ 2 \times 10^{-4} $
• D. $ 4 \times 10^{-4} $

Answer 1

Answer: (C)

$AX _{2} \rightarrow \underset{x}{A ^{2+}}+\underset{2x}{2 X ^{-}}$
$K _{ sp }=4 x ^{3} ; x =\sqrt[3]{\frac{3.2 \times 10^{-11}}{4}} ; x $
$=2 \times 10^{-4}$ mole / litre