Answer :
To balance redox reactions, assign oxidation numbers to the reactants and products to determine how many moles
of each species are needed to conserve mass and charge. First, separate
the equation into two half-reactions, the oxidation portion and the
reduction portion. This is called the half-reaction method of balancing redox reactions or the ion-electron method.
Each half-reaction is balanced separately and then the equations are
added together to give a balanced overall reaction. We want the net
charge and number of ions to be equal on both sides of the final
balanced equation.
For this example, let's consider a redox reaction between KMnO4and HI in an acidic solution:
MnO4- + I- → I2 + Mn2+