Question

The solubility product of $PbC{l}_2$ at $20^{\circ }C$ is $1.5\times 10^{-4}$ . Calculate the solubility.

• A. $3.75\times 10^{-4}$
• B. $3.34\times 10^{-2}$
• C. $3.34\times 10^2$
• D. None of these

Answer 1

Answer: (B)

$PbC{l}_2\underset{S}{P{b}^{2+}}+\underset{2S^2}{2C{l}^{-}}$
$K_{sp}=S\times (2S{)}^{2}4S^3$
$S=\sqrt[3]{\frac{K_{sp}}{4}}=\sqrt[3]{\frac{1.5\times 10^{-4}}{4}}$
$=3.34\times {10}^{-2}$