Question

If the solubility product of a sparingly soluble salt $M{X}_2$ at ${25}^{o}C$ is $1.0\times {10}^{-11}$, the solubility of the salt in moles $L^{-1}$ at this temperature will be:

• A. $2.46\times {10}^{14}$
• B. $1.36\times {10}^{-4}$
• C. $2.60\times {10}^{-7}$
• D. $1.20\times {10}^{-10}$

Answer 1

The correct option is B $1.36\times {10}^{-4}$

$M{X}_2\to M^{+}+2X^{-}$

At Equilibrium,

$\left[M^{+}\right]=s,\left[X^{-}\right]=2s$

$K_{sp}=4s^3$

$s=1.35\times {10}^4$