The given chemical equation represents the reaction pathway for the conversion of ammonia (NH3) to ammonium nitrate (NH4NO3) via nitric oxide (NO) and nitric acid (HNO3). This reaction pathway involves the oxidation of ammonia to nitric oxide by nitric acid, and the subsequent reaction of nitric oxide with oxygen to form nitrogen dioxide, which further reacts with water to form nitric acid. Finally, the ammonium nitrate is formed by neutralizing the nitric acid with ammonia.