Question

The solubility product of a sparingly soluble salt AX is \(4.9 \times 10^{-13}\). What is its solubility in \(\text{mol dm}^{-3}\) ?

• A. \(2.4 \times 10^{-13}\)
• B. \(4.9 \times 10^{-7}\)
• C. \(7.0 \times 10^{-7}\)
• D. \(7.0 \times 10^{-13}\)

Hint:

For 1:1 salt → \(K_{sp} = s^2\)

Answer 1

The Correct Option is C

Concept:
\[ \text{AX} \rightleftharpoons \text{A}^+ + \text{X}^- \quad K_{sp} = s^2 \] Step 1: Find solubility. \[ s = \sqrt{4.9 \times 10^{-13}} \]
Step 2: Calculate. \[ s = 7.0 \times 10^{-7} \]
Step 3: Conclusion. Solubility = \(7.0 \times 10^{-7}\)