Question

What is the solubility in pure water of ba(io3)2 in moles per liter at 25 ˚c? [ksp (25 ˚c) = 6.0  10–10]?

Answer 1

Ba(IO₃)₂(s) partially dissociates in water as Ba²⁺(aq) and IO₃⁻(aq).
Ba(IO₃)₂(s) ⇄ Ba²⁺(aq) + 2IO₃⁻(aq)
Initial
Change -X +X 2X
Equilibrium X 2X

Ksp = [Ba²⁺(aq)] x [IO₃⁻(aq)]²
6.0 x 10⁻¹⁰ = X * (2X)²
6.0 x 10⁻¹⁰ = 4X³
X = 5.313 x 10⁻⁴ mol/L

Hence, the solubility of the Ba(IO₃)₂(s) is 5.313 x 10⁻⁴ mol/L