Balancing Using Oxidation Numbers
| 1st step: | Balance all atoms with the exception of Hydrogen and Oxygen. |
| 2nd step: | Calculate the change in oxidation number for the reduced and oxidized element. |
| 3rd step: | Put coefficients in front of the reduced and oxidized elements so the gain of electrons made by the reduced species equals the loss of electrons by the oxidized species. |
| 4th step: | Add H2O to balance the oxygen atoms. |
| 5th step: | Add H+ to balance the hydrogen atoms. |
| 6th step: | If basic, add OH– to both sides equivalent to the amount of H+ and eliminated duplicate water molecules on either side of the equation. |
| 7th step: | Double check that the final charge balances. |
Example 1) Write a balanced equation for HClO2 and I-
when they react to
produce Cl2 and HIO in acidic solution.
Example 2) Write the balanced equation for ClO3- and
MnO2 when they react
in basic solution to form Cl2 and MnO4-