Q. The solubility product of a salt having general formula $MX_{2}$ in water is $4 \times 10^{- 12}$. The concentration of $M^{2 +}$ ions in the aqueous solution of the salt is
A) $2.0 \times 10^{- 6}M$
B) $1.0 \times 10^{- 4}M$
C) $1.6 \times 10^{- 4}M$
D) $4.0 \times 10^{- 10}M$
Explanation
(b)
$MX_{2} = M^{2 +} + 2X^{-}$
$s\ \ \ \ \ \ \ \ \ \ \ 2s$
$K_{sp} = (2s)^{2}(s) = 4s^{3}$
$\Rightarrow s = \sqrt[3]{\frac{K_{sp}}{4}} = \sqrt[3]{\frac{4 \times 10^{- 12}}{4}} = 1.0 \times 10^{- 4}M$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.