5 H2C2O4 (aq) + 2 KMnO4 (aq) + 3 H2SO4 (aq) → 2 MnSO4 (aq) + K2SO4 (aq) + 10 CO2 (g) + 8 H2O (l)
This is an oxidation-reduction (redox) reaction:
2 MnVII + 10 e- → 2 MnII (reduction)
10 CIII - 10 e- → 10 CIV (oxidation)
KMnO4 is an oxidizing agent, H2C2O4 is a reducing agent.
This is a gas evolution reaction, CO2 is the formed gas.