OnlineCBT
Chemistry · EQUILIBRIUM
हिन्दीComparing two sparingly soluble salts at 298 K: \( \text{Ni(OH)}_2 \) (\( K_{sp} = 2.0 \times 10^{-15} \)) and \( \text{AgCN} \) (\( K_{sp} = 6.0 \times 10^{-17} \)). Which statement regarding their molar solubilities in pure water is correct? Which of the above statements is/are correct?
Correct answer · Option 3
\( \text{Ni(OH)}_2 \) is more soluble than \( \text{AgCN} \) because its calculated molar solubility is \( 7.94 \times 10^{-6}\text{ M} \) versus \( 7.75 \times 10^{-9}\text{ M} \) for \( \text{AgCN} \).
Explanation
For \( \text{AgCN} \), \( S_1 = \sqrt{6.0 \times 10^{-17}} \approx 7.75 \times 10^{-9}\text{ M} \). For \( \text{Ni(OH)}_2 \), \( 4S_2^3 = 2.0 \times 10^{-15} \implies S_2 = (0.50 \times 10^{-15})^{1/3} \approx 7.94 \times 10^{-6}\text{ M} \). Thus, \( \text{Ni(OH)}_2 \) is much more soluble.
