Write the steps to be followed while balancing redox equation by oxidation number method.

Explanation

Oxidation number method:
This method is based on the fact that
Number of electrons lost by atoms = Number of electrons gained by atoms
Steps to be followed while balancing Redox reactions by Oxidation Number method:
1. Write skeleton equation representing redox reaction
2. Write the oxidation number of atoms undergoing oxidation and reduction.
3. Calculate the increase or decrease in oxidation numbers per atom.
4. Make increase in oxidation number equal to decrease in oxidation number by multiplying the formula of oxidant and reductant by suitable numbers.
5. Balance the equation atomically on both sides except O and H atoms.
6. Balance oxygen atoms by adding required number of water molecules to the side deficient in oxygen atoms.
7. Add required number of `H^(+)` ions to the side deficient in hydrogen atom if the reaction is in acidic medium.
8. For reactions in basic medium, add `H_(2)O` molecules to the side deficient in hydrogen atoms and simultaneously add equal number of `OH^(-)` ions on the other side of the equation.
9. Finally balance the equation by cancelling common species present on both sides of the equation.