10 Cr^IIO + 2 HN^VO₃ → N₂⁰ + 5 Cr₂^IIIO₃ + H₂O

This is an oxidation-reduction (redox) reaction:

2 N^V + 10 e^- → 2 N⁰ (reduction)

10 Cr^II - 10 e^- → 10 Cr^III (oxidation)

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