QuestionIonic equilibrium / Ksp
The solubility product of Ag₂CrO₄ is 32 × 10⁻¹². What is the concentration of CrO₄²⁻ ion in that solution?
- (a) 2 × 10⁻⁴ M
- (b) 16 × 10⁻⁴ M
- (c) 8 × 10⁻⁴ M
- (d) 8 × 10⁻⁸ M
Answer: (a) 2 × 10⁻⁴ M
Ag₂CrO₄ ⇌ 2Ag⁺ + CrO₄²⁻. Ksp = (2s)²·s = 4s³ = 32 × 10⁻¹² → s³ = 8 × 10⁻¹² → s = 2 × 10⁻⁴ M = [CrO₄²⁻] → (a).