What is the solubility of La(IO₃)₃ in water? (Ksp of La(IO₃)₃ is 7.5 × 10⁻¹²)

Answer 1

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

Ksp = [La³⁺][IO₃^-]³

Let [La³⁺] = x, and then [IO₃^-] = 3x

Ksp = (x)(3x)³

7.5x10^-12 = 27x⁴

x⁴ = 2.78x10^-13

x = 7.26x10^-4 M = [La³⁺] = molar solubility of La(IO₃)₃

(be sure to check the math)