CBSE Class 11-science Answered

Half-Reaction Method (or Ion-Electron Method) is to split an unbalanced redox equation into two half-reactions, oxidation and reduction half-reactions. Both half-reactions are then balanced in according to the change of electrons. It is applied the best for redox reactions with ions and in aqueous solution.

Chemical equations with changes of oxidation numbers can be balanced using half-equation method. This module can guide you through step-by-step in balancing redox reactions using this method. Here are the steps:

1. Separate into half-reactions.

2. Balance the oxidizing and reducing elements in each half-reaction.

3. Balance atoms other than O and H.

4. In acidic solution, balance oxygen with H2O. In basic solution, balance oxygen with OH- and H2O.

5. In acidic solution, balance hydrogen with H+. In basic solution, balance hydrogen with OH- and H2O.

6. Balance each half-reaction for charge with e-.

7. Multiply each half-reaction by a coefficient so the numbers of electrons are the same in each and add both half-equations together.

8. Cancel common reactants and products.

9. Eliminate fractions by multiplying a common factor if needed.

10. Complete the equation by final inspection.