Balancing Redox Reactions in Acid or Base
Assign oxidation Numbers and identify ox and red species
Separate into half reactions
Balance each half reaction for mass
- Acid: Balance O’s with H2O and then H’s with H+
- Base: Balance H’s and O’s with OH- and H2O. Add H2O to the side of the reaction with the fewest H atoms.
Balance each half reaction for charge by adding electrons
Multiply half reactions by an appropriate factor to balance electrons gained with electrons lost
Acid: VO2+(aq) + Zn(s) ? VO2+(aq) + Zn2+(aq)
Base: MnO4-(aq) + HO2-(aq) ? MnO42-(aq) + O2(g)