Balance the following redox reaction:
MnO4-(aq) + C2O42-(aq) -> Mn2+(aq) + CO2(g)
First, you must identify what is being reduced and what is being oxidized. Through inspection of the oxidation states of the elements involved, we realize that manganese is going from an oxidation state of +7 to an oxidation state of +2. On the other hand, carbon is going from +3 to +4. Therefore Mn is reduced and ...