What is the solubility of La(IO₃)₃ in a solution that contains 0.450 M La³⁺ ions? (Ksp of La(IO₃)₃ is 7.5 × 10⁻¹²)

Answer 1

Common Ion Effect:

The common ion is La³⁺

La(IO₃)₃(s) <==> La³⁺(aq) + 3IO₃^-(aq)

Ksp = [La³⁺][IO₃^-]³

Since the [La³⁺] is given as 0.450 M, the additional concentration provided by the La(IO₃)₃ is insignificant..

7.5x10^-12 = (0.450)(3x)³

27x³ = 1.67x10^-11

x = 8.5x10^-5 M