Question

If the solubility product of $BaS{O}_4$ is $1.5\times {10}^{-10}$ in water. Its solubility, in moles per litre, is.

• A. $1.5\times {10}^{-9}$
• B. $3.9\times {10}^{-5}$
• C. $7.5\times {10}^{-5}$
• D. $1.2\times {10}^{-5}$

Answer 1

The correct option is D $1.2\times {10}^{-5}$

Let $S$ be the molar solubility of barium sulphate.

For barium sulphate;

$K_{sp}=\left[B{a}^{2+}\right]\left[S{O}_4^{2-}\right]$

$=S\times S=S^2$

Molar solubility of barium sulphate, $S=\sqrt{Ksp}$

$=\sqrt{1.5\times {10}^{-10}}$

$=1.2\times {10}^{-5}$ M