Question

Calculate the solubility (in g / L) of a generic salt with a formula of A2 B, a Ksp of 3.60 × 10^−12 and a molar mass of 106 g / mol.

Answer 1

A2B ----------->   2A+ + B2-

                           2S         S

Ksp = [A+]^2[B2-]

3.60 x 10^-12 = (2S)^2 x S

4S^3 = 3.60 x 10^-12

S = 9.65 x 10^-5 M

solubility = 9.65 x 10^-5 mol / L

               = 9.65 x 10^-5 x 106

solubility = 0.0102 g / L