The molar solubility of ag2s is 1.26 * 10-16 m in pure water. calculate the ksp for ag2s.

Answer is: Ksp for silver sulfide is 8.00·10⁻⁴⁸.

Reaction of dissociation: Ag₂S (s) → 2Ag⁺ (aq) + S²⁻ (aq).

s (Ag₂S) = s (S²⁻) = 1.26·10⁻¹⁶ M.

s (Ag⁺) = 2s (Ag₂S) = 2.52·10⁻¹⁶ M; equilibrium concentration of silver cations.

Ksp = s (Ag⁺) ² · s (S²⁻).

Ksp = (2.52·10⁻¹⁶ M) ² · 1.26·10⁻¹⁶ M.

Ksp = 6.35·10⁻³² M² · 1.26·10⁻¹⁶ M.

Ksp = 8.00·10⁻⁴⁸ M³.