Which of the following is the correctly balanced chemical equation for the reaction of ClO⁻(aq) with Cr(OH)₃(s) to form Cl⁻(aq) and CrO₄²⁻(aq) in a basic solution?

• A. ClO⁻(aq) + Cr(OH)₃(s) + OH⁻(aq) → Cl⁻(aq) + CrO₄²⁻(aq) + H₂O(l)
• B. ClO⁻(aq) + Cr(OH)₃(s) → Cl⁻(aq) + CrO₄²⁻(aq) + OH⁻(aq)
• C. 2 ClO⁻(aq) + Cr(OH)₃(s) + 3 OH⁻(aq) → 2 Cl⁻(aq) + CrO₄²⁻(aq) + H₂O(l)
• D. 3 ClO⁻(aq) + Cr(OH)₃(s) + 4 OH⁻(aq) → 3 Cl⁻(aq) + CrO₄²⁻(aq) + 2 H₂O(l)

Answer: (D)

Verified step by step guidance

1. Identify the oxidation and reduction half-reactions. ClO⁻ is reduced to Cl⁻, and Cr(OH)₃ is oxidized to CrO₄²⁻.
2. Write the half-reaction for the reduction of ClO⁻ to Cl⁻: ClO⁻(aq) + 2 e⁻ + H₂O(l) → Cl⁻(aq) + 2 OH⁻(aq).
3. Write the half-reaction for the oxidation of Cr(OH)₃ to CrO₄²⁻: Cr(OH)₃(s) + 5 OH⁻(aq) → CrO₄²⁻(aq) + 3 H₂O(l) + 3 e⁻.
4. Balance the electrons between the two half-reactions by multiplying the reduction half-reaction by 3 and the oxidation half-reaction by 2.
5. Combine the balanced half-reactions, ensuring that all species are balanced, including electrons, to obtain the overall balanced equation: 3 ClO⁻(aq) + Cr(OH)₃(s) + 4 OH⁻(aq) → 3 Cl⁻(aq) + CrO₄²⁻(aq) + 2 H₂O(l).