Question

The solubility product of a salt $A_{2}B$ is $4\times {10}^{-9}$. Its solubility would be:

• A. $4\times {10}^{-2}M$
• B. $2\times {10}^{-4}M$
• C. $1\times {10}^{-4}M$
• D. $1\times {10}^{-3}M$

Answer 1

Answer: (D)

$1\times {10}^{-3}M$

$A_{2}B\rightleftharpoons 2A^{+}+B^{-}$

Let 'S' be solubility of $A_{2}B$

$K_{sp}=\left[2S{]}^2\right[S]=4S^3=4\times {10}^{-9}$

$S={10}^{-3}M$