Question

The solubility of $ A{{g}_{2}}S $ is $ [{{K}_{sp}}=256\times {{10}^{-6}}]: $

• A. $ 4\times {{10}^{-2}} $
• B. $ 4\times {{10}^{-3}} $
• C. $ 0.4\times {{10}^{-2}} $
• D. $ 0.4\times {{10}^{-3}} $

Answer 1

Answer: (A)

Let solubility of $Ag _{2} S =x g / L$
$\underset{\text{concentration}}{Ag_{2}S} \to \underset{2x}{AG^{+}} + \underset{x}{S^{2-}}$
$K_{s p}=\left[ Ag ^{+}\right]^{2}\left[ S ^{2-}\right]$
$=(2 x)^{2}(x)$
$=4 x^{3}$
Given, $K_{s p}=256 \times 10^{-6}$
$\therefore 256 \times 10^{-6}=4 x^{3}$
or $x=\sqrt[3]{\frac{25 \times 10^{-6}}{4}}$
$=4 \times 10^{-2}$