Question

A salt with general formula $MX_{2}$ has solubility product $4\times 10^{- 12}$ in water. The concentration of $M^{2 +}$ ions in the aqueous solution of the salt is

• A. $2\times 10^{- 6} \, M$
• B. $1\times 10^{- 4} \, M$
• C. $1.6\times 10^{- 4} \, M$
• D. $4\times 10^{- 10} \, M$

Answer 1

Answer: (B)

It is ternary electrolyte.
$\therefore K_{s p}=4S^{3}$
$S=10^{- 4} \, M$
$\therefore \left[M^{2 +}\right]=10^{- 4}M$