balancing redox equations

Question

In the reaction MnO₄⁻ + Fe²⁺ + H⁺ → Mn²⁺ + Fe³⁺ + H₂O (acidic medium), the ratio of MnO₄⁻ to Fe²⁺ is:

RankGuru · Accepted Answer

Using the **Ion-Electron Method** to balance the redox reaction:
1. **Reduction Half-reaction**: $MnO_4^- + 8H^+ + 5e^- 	o Mn^{2+} + 4H_2O$
- (Oxidation state of $Mn$ changes from $+7$ to $+2$, requiring $5e^-$).
2. **Oxidation Half-reaction**: $Fe^{2+} 	o Fe^{3+} + e^-$
- (Oxidation state changes from $+2$ to $+3$, releasing $1e^-$).
3. **Electron Balance**: To equalize electrons, multiply the oxidation half-reaction by $5$.
- Result: $1 \, MnO_4^-$ reacts with $5 \, Fe^{2+}$.
- Therefore, the stoichiometric ratio is **1:5**.

Rank Guru

balancing redox equations

Select the correct option: