The overall reaction takes place in the process is
2KMnO4+3H2SO4+5(COOH)2→K2SO4+2MnSO4+8H2O+10CO2↑
Potassium permanganate is a strong oxidising agent and in the presence of sulfuric acid it acts as a powerful oxidising agent. In acidic medium the oxidising ability of KMnO4 is represented by the following equation.
MnO4−+8H++5e−→Mn2++4H2O