Calculate the molar solubility of CuI (Ksp = 1.27 × 10−12).

Solution 88P:

Consider the equation

CuI.(s) ⇆ Cu+(aq) + I-(aq)

Let us consider the molar solubility of CuI (s) is “ S” mol/L.

Thus,

Solubility product = [Cu+(aq)][ I-(aq)]

Ksp = [Cu+(aq)][ I-(aq)] ------(1)

We know

Solubility product Ksp for CuI is 1.27 × 10−12

Therefore, from equation (1)

1.27 × 10−12 = S. S

S2 =1.27 × 10−12

= (1.27 × 10−12 )½ = 1.127 x 10-6 M

Thus, the molar solubility of CuI is 1.127 x 10-6 M.