4 Cd0 + 10 HNVO3 4 CdII(NVO3)2 + N-IIIH4NVO3 + 3 H2O

This is an oxidation-reduction (redox) reaction:

4 Cd0 - 8 e- 4 CdII (oxidation)

NV + 8 e- N-III (reduction)

Change the oxidation states