Use the ksp values in the table to calculate the molar solubility of fe (oh) 2 in pure water

The solubility equilibrium for Fe (OH) 2 is:

Fe (OH) 2 (aq) ↔ Fe²⁺ (aq) + 2OH⁻ (aq)

Ksp (Fe (OH) 2) = [Fe²⁺][OH⁻]²

If 's' is the molar solubility of Fe (OH) 2 then:

Ksp = (s) (2s) ² = 4s³

the solubility constant Ksp for Fe (OH) 2 can be obtained from any online database = 4.87*10⁻¹⁷

4.87*10⁻¹⁷ = 4s³

s³ = 1.218*10⁻¹⁷

s = ∛1.218*10⁻¹⁷ = 2.33*10⁻⁶ M

Molar solubility of Fe (OH) 2 = 2.33*10⁻⁶ M