Complete and balance the following half-reaction in basic solution. Be sure to include the proper phases for all species within the reaction. Cr₂O₇²⁻(aq) → Cr³⁺(aq)

Question

Complete and balance the following half-reaction in basic solution. Be sure to include the proper phases for all species within the reaction. Cr₂O₇²⁻(aq) → Cr³⁺(aq)

Answer 1

Cr₂O₇²⁻(aq) → Cr³⁺(aq)

Cr₂O₇^2-(aq) ==> 2Cr³⁺(aq) + 7H₂O(l) .. balanced for Cr and O

Cr₂O₇^2-(aq) + 14H₂O(l) ==> 2Cr³⁺(aq) + 7H₂O(l) + 14OH^-(aq).. balanced for Cr, O and H (using base, OH-)

Cr₂O₇^2-(aq) + 14H₂O(l) + 6e- ==> 2Cr³⁺(aq) + 7H₂O(l) + 14OH^-(aq) .. balance for mass and charge

Combine and cancel like terms to get the final balanced equation:

Cr₂O₇^2-(aq) + 7H₂O(l) + 6e- ==> 2Cr³⁺(aq) + 14OH^-(aq) .. balanced reduction half reaction