Question

The solubility of ZnS is measured and found to be 4.50×10^-11 g/L. Use this information to calculate a K_sp value for zinc sulfide.

Answer 1

Given:-

Solubility is given in g/L. But To calculate K_sp we require the solubility in mol/L (molar solubility)

Hence first we convert g/L solubility into mol/L solubility.

We have,

...(1)

Molar mass of ZaS = 97.47 g/mol

from eq(1) we have,

The solubility equilibrium for ZnS is

the solubility product is

  

Here, x = 1 and y = 1

if S is molar solubility of ZnS then

...(2)

Now,

from eq(2)

Therefor, K_sp value for ZnS is .

Note:-