Exam Style Question - 2

Question: Write a half-equation for the reduction of MnO₄^- to Mn²⁺ in acidic solution.Step 1: balance the manganese. MnO₄^- → Mn²⁺Step 2: balance the oxygen by adding water to the other side. MnO₄^- → Mn²⁺ + 4H₂OStep 3: balance the hydrogen by adding H⁺ ions. MnO₄^- + 8H⁺ → Mn²⁺ + 4H₂OStep 4: balance the charge with electrons. The left side has a charge of +7 and the right side +2, so 5 electrons are added to the left: MnO₄^- + 8H⁺ + 5e^- → Mn²⁺ + 4H₂OCheck: manganese goes from +7 to +2, a change of 5, which matches the 5 electrons gained. This is a reduction half-equation because electrons appear on the left.