4 Cu0 + 10 HNVO3 N2IO + 4 CuII(NVO3)2 + 5 H2O

This is an oxidation-reduction (redox) reaction:

4 Cu0 - 8 e- 4 CuII (oxidation)

2 NV + 8 e- 2 NI (reduction)

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