Balancing the redox reaction MnO4⁻ + H2O2 → Mn²⁺ + O2 (in acidic medium), what are the stoichiometric coefficients of H2O2 and MnO4⁻?
Correct: A
Oxidation (H₂O₂ → O2: O oxidation state increases from -1 to 0. Mn is reduced from +7 to +2. Balanced equation: 2MnO4⁻ + 5H2O2 + 6H+ → 2Mn²⁺ + 5O2 + 8H2O. Ratio: MnO4⁻:5, H2O2:2.