Question

The molar solubility $\left[\right.in \, mol \, L^{- 1}\left]\right.$ of a sparingly soluble salt $MX_{4}$ is ‘s’. The corresponding solubility product is Ksp.s is given in terms of Ksp by the relation

• A. $s=\left(\frac{K s p}{256}\right)^{1 / 5}$
• B. $s=\left(128 K s p\right)^{1 / 4}$
• C. $s=\left(\frac{K s p}{128}\right)^{1 / 6}$
• D. $s=\left(256 K s p\right)^{1 / 5}$

Answer 1

Answer: (A)

For the solute $\text{AxBy} \overset{}{\rightleftharpoons} \text{xA} + \text{yB}$
$Ksp=x^{x}y^{y}\left(s\right)^{x + y}$
$\text{MX}_{4} \overset{}{\rightleftharpoons} \text{M}^{4 +} + 4 \text{X}^{-}$
x = 1, y = 4
$Ksp=\left(4\right)^{4}\left(1\right)^{1}\left(s\right)^{5}=256s^{5}$
$s=\left(\frac{K s p}{256}\right)^{1 / 5}$