In the following unbalanced reaction: MnO₄⁻ + Fe²⁺ + H⁺ → Mn²⁺ + Fe³⁺ + H₂O, what is the ratio of MnO₄⁻ to Fe²⁺ in the balanced equation?
1 : 1
1 : 3
1 : 5
2 : 5
📝 Detailed explanation
Mn changes from +7 to +2 (gains 5e⁻). Fe changes from +2 to +3 (loses 1e⁻). To balance the electrons, 5 moles of Fe²⁺ are needed for every 1 mole of MnO₄⁻.
