Balance the following equation in an acidic medium: Cr₂O₇²⁻ + Fe²⁺ → Cr³⁺ + Fe³⁺. What is the coefficient of Fe²⁺ in the balanced equation?
- 1
- 3
- 6
- 7
📝 Detailed explanation
Half-reactions:1) Cr₂O₇²⁻ + 14H⁺ + 6e⁻ → 2Cr³⁺ + 7H₂O
2) Fe²⁺ → Fe³⁺ + 1e⁻.
To equalize electrons, multiply the second reaction by 6. The coefficient for Fe²⁺ is 6.