Question

Choose the most correct answer :

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

पर्याय

• 7.2 × 10^–7

• 1.35 × 10^–4

• 7.2 × 10^–8

• 13.5 × 10^–8

Answer 1

The solubility product of a sparingly soluble salt AX is 5.2 × 10^–13. Its solubility in mol dm^–3 is ${\displaystyle \underline{7.2\times {10}^{-7}}}$.

Explanation:

K_sp = 5.2 × 10^–13

$$\underset{\mathrm{s}}{\mathrm{AX}}\stackrel{-\rightharpoonup }{\leftharpoondown -}\underset{\mathrm{s}}{\mathrm{A}}{\phantom{A}}^{-}+\underset{\mathrm{s}}{\mathrm{X}}{\phantom{A}}^{+}$$

K_sp = [A^–][X⁺]

= s × s

5.2 × 10^–13 = s²

${\displaystyle \sqrt{{10}^{-13}}=\sqrt{{10}^{-12}}}$ = 10^–6

0.52 × 10^–12 = s²

${\displaystyle \sqrt{0.52\times {10}^{-12}}}$ = s

0.7211 × 10^–6 = s

s = 7.211 × 10^–7