5 (N-IIIH4)2Cr2VIO7 6 NIIO + 5 Cr2IIIO3 + 4 N-IIIH3 + 14 H2O

This is an oxidation-reduction (redox) reaction:

6 N-III - 30 e- 6 NII (oxidation)

10 CrVI + 30 e- 10 CrIII (reduction)

Change the oxidation states