5 K2C2IIIO4 + 2 KMnVIIO4 + 8 H2SO4 2 MnIISO4 + 6 K2SO4 + 10 CIVO2 + 8 H2O

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, K2C2O4 is a reducing agent.