Question

If $K_{s p}$ is the solubility products of a sparingly soluble salt $A_{3} X_{2}$, then its solubility is :

• A. $\left(K_{s p} / 108\right)^{1 / 5}$
• B. $\left(K_{s p}\right)^{1 / 5}$
• C. $\left(K_{\text {sp }} / 72\right)^{1 / 5}$
• D. $\left(K_{s p}\right)^{1 / 2}$

Answer 1

Answer: (A)

$\underset {1-s}{A_3 X_2} \rightleftharpoons \underset {3s}{3A^{2+}} + \underset {2s}{2X^{3-}} $

$K_{\mathrm{sp}}=(3 s)^{3}(2 s)^{2}=108 s^{5}$

$s=\left(\frac{K_{s p}}{108}\right)^{1 / 5}$