((N-IIIH4)2Cr2VIO7) N20 + Cr2IIIO3 + 4 H2O

This is an oxidation-reduction (redox) reaction:

2 N-III - 6 e- 2 N0 (oxidation)

2 CrVI + 6 e- 2 CrIII (reduction)

((NH4)2Cr2O7) is a reducing agent, ((NH4)2Cr2O7) is an oxidizing agent.