Question

Which of the following species is more soluble in water?

• A. $M(OH{)}_3,(K_{sp}=1\times {10}^{-35}{M}^4)$
• B. $M(OH{)}_2,(K_{sp}=1\times {10}^{-30}{M}^3)$
• C. $MOH,(K_{sp}=1\times {10}^{-28}{M}^2)$
• D. $MOH,(K_{sp}=1\times {10}^{-26}{M}^2)$

Answer 1

The correct option is A $M(OH{)}_3,(K_{sp}=1\times {10}^{-35}{M}^4)$

The expression for the solubility of $M(OH{)}_3$ is
$s=\sqrt[4]{4\frac{K_{sp}}{27}}$
Substitute values in the above equation
$s=\sqrt[4]{4\frac{{10}^{-35}}{27}}=7.8\times {10}^{-10}$
The expression for the solubility of $M(OH{)}_2$ is $s=\sqrt[3]{3\frac{K_{sp}}{4}}$
Substitute values in the above equation,
$s=\sqrt[3]{3\frac{1\times {10}^{-30}}{4}}=6.3\times {10}^{-11}$
The expression for the solubility of $MOH$ is $s=\sqrt{K_{sp}}$
Substitute values in the above equation,
$s=\sqrt{1\times {10}^{-28}}=1\times {10}^{-14}$
The expression for the solubility of $MOH$ is $s=\sqrt{K_{sp}}$
Substitute values in the above equation,
$s=\sqrt{1\times {10}^{-26}}=1\times {10}^{-13}$