2 [CrII(N-IIIH2CIVON-IIIH2)6]3[CrIII(CIIN-III)6]2 + 137 K2Cr2VIO7 + 515 H2SO4 89 K2SO4 + 96 KNVO3 + 142 Cr2III(SO4)3 + 60 CIVO2 + 587 H2O

This is an oxidation-reduction (redox) reaction:

24 CII - 48 e- 24 CIV (oxidation)

96 N-III - 768 e- 96 NV (oxidation)

6 CrII - 6 e- 6 CrIII (oxidation)

274 CrVI + 822 e- 274 CrIII (reduction)

Change the oxidation states