Calculating Solubility from the Ksp

Question

Calculate the molar solubility of calcium sulfate given K_sp = 2.4 x 10^-5

Answer 1

CaSO₄(s) <==> Ca²⁺(aq) + SO₄^2-(aq)

Let x = [Ca²⁺]; then [SO₄^2-] = x

Ksp = [Ca²⁺][SO₄^2-]

2.4x10^-5 = (x)(x)

x² = 2.4x10^-5

x = 4.9x10^-3 M = molar solubility of CaSO₄