Solubility product constant () of salts of types MX, MX and MX at temperature, are , and , respectiv — Ionic Equilibrium Chemistry Question
Question
Solubility product constant ($K_{sp}$) of salts of types MX, MX$_2$ and M$_3$X at temperature, $T$ are $4.0 \times 10^{-8}$, $3.2 \times 10^{-14}$ and $2.7 \times 10^{-15}$, respectively. Solubilities (in M) of the salts at temperature, $T$, are in the order
💡 Solution & Explanation
For MX: $S^2 = 4.0 \times 10^{-8} \implies S = 2.0 \times 10^{-4} \text{ M}$.<br>For $\text{MX}_2$: $4S^3 = 3.2 \times 10^{-14} \implies S^3 = 8.0 \times 10^{-15} \implies S = 2.0 \times 10^{-5} \text{ M}$.<br>For $\text{M}_3\text{X}$: $27S^4 = 2.7 \times 10^{-15} \implies S^4 = 10^{-16} \implies S = 10^{-4} \text{ M}$.<br>Comparing them: $2.0 \times 10^{-4} > 1.0 \times 10^{-4} > 2.0 \times 10^{-5}$, which means the order of solubility is $\text{MX} > \text{M}_3\text{X} > \text{MX}_2$.