Question

The solubility product of a sparingly soluble salt $A{X}_2$ is $3.2\times {10}^{-11}$. Its solubility (in moles/litres) is:

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

Answer 1

The correct option is A $2\times {10}^{-4}$

$A{X}_2\to \underset{x}{A^{2+}}+\underset{2x}{2X^{-}}$

$K_{sp}=4x^3;x=\sqrt[3]{3\frac{3.2\times {10}^{-11}}{4}};x=2\times {10}^{-4}$ mole/ litre