Chemistry

Problem

The minimum pH required to prevent the precipitation of

\text{ZnS}

in a solution having

0.1 M \text{ZnCl}_2

and

0.1 M \text{H}_2\text{S}

K_{a1} \times K_{a2}

for

\text{H}_2\text{S}

10^{-20}

and

K_{sp}

\text{ZnS} = 10^{-21}