2 CH4 + 5 O2 → 8 HO + 2 CO
This is an oxidation-reduction (redox) reaction:
2 C-IV - 12 e- → 2 CII (oxidation)
8 O0 + 8 e- → 8 O-I (reduction)
2 O0 + 4 e- → 2 O-II (reduction)
CH4 is a reducing agent, O2 is an oxidizing agent, O2 is an oxidizing agent.