5 C0 + 4 HNVO3 2 N20 + 5 CIVO2 + 2 H2O

This is an oxidation-reduction (redox) reaction:

5 C0 - 20 e- 5 CIV (oxidation)

4 NV + 20 e- 4 N0 (reduction)

C is a reducing agent, HNO3 is an oxidizing agent.