8 HN3 (l) + Br2 (aq) → 2 NH4Br (aq) + 11 N2 (g)
This is an oxidation-reduction (redox) reaction:
2 Br0 + 2 e- → 2 Br-I (reduction)
22 N-1/3 - 22/3 e- → 22 N0 (oxidation)
2 N-1/3 + 16/3 e- → 2 N-III (reduction)
Br2 is an oxidizing agent, HN3 is a reducing agent, HN3 is an oxidizing agent.