Calculate the solubility of barium carbonate, baco3, in pure water (ksp = 2.0  10–9 for baco3).

Answer is: molar solubility of barium carbonate is 4.47·10⁻⁵ M.

Chemical reaction:BaCO₃(s) → Ba²⁺(aq) + CO₃²⁻(aq).

Ksp = 2.0·10⁻⁹.

s(BaCO₃) = ?M.

s(BaCO₃) = s(Ba²⁺) =s(CO₃²⁻) = x.

Ksp = s(Ba²⁺) · s(CO₃²⁻).

Ksp = x · x.

2.0·10⁻⁹ = x².

x = √2.0·10⁻⁹ = 4.47·10⁻⁵ M.

first one is the correct answer