IV. The solubility product of a sparingly soluble salt AX is 5.2×10-13. Its solubility in mol dm-3 is

Choose the most correct answer: 

iv. The solubility product of a sparingly soluble salt AX is 5.2×10-13. Its solubility in mol dm-3 is
a. 7.2 × 10-7

b. 1.35 × 10-4

c. 7.2 × 10-8

d. 13.5 × 10-8

Answer:-

The solubility product of a sparingly soluble salt \(AX\) is \(5.2 \times 10^{-13}\). Its solubility in mol dm\(^{-3}\) is 7.2 \times 10^{-7}.

Explanation:

\(K_{sp} = 5.2 \times 10^{-13}\)

\[ \ce{AX <=> A^{-} + X^{+}} \]

\(K_{sp} = [A^{-}][X^{+}] = s \times s\)

\(5.2 \times 10^{-13} = s^{2}\)

\(\sqrt{10^{-13}} = \sqrt{10^{-12}} = 10^{-6}\)

\(0.52 \times 10^{-12} = s^{2}\)

\(\sqrt{0.52 \times 10^{-12}} = s\)

\(0.7211 \times 10^{-6} = s\)

\(s = 7.211 \times 10^{-7}\)

Chapter 3 Ionic Equilibira – Exercises (page 61)