First slide

Ionic equilibrium

Question

An acidified solution of 0.05 M Zn²⁺ is saturated with 0.1 M H₂S. What is the minimum molar concentration (M) of H⁺
required to prevent the precipitation of ZnS?
Use Ksp (ZnS) = 1.25 × 10^–22 and Overall dissociation constant of H₂S , KNET = K₁K₂ = 1 × 10^–21

Moderate

Solution

For ppt, $[{Zn}^{+ 2}] [S^{- 2}] = K_{sp}$
$[S^{- 2}] = \frac{1.25 \times 10^{- 22}}{0.05}$
= 2.5 × 10^–21 M
$\begin{array}{l} H_{2} S ⇌ 2 H^{+} + S^{- 2} \\ K_{Net} = 10^{- 21} = \frac{{[H^{+}]}^{2} \times 2.5 \times 10^{- 21}}{0.1} \\ {[H^{+}]}^{2} = \frac{1}{25} \\ [H^{+}] = \frac{1}{5} M = 0.2 M \end{array}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App