Ostwald process

The Ostwald process is a commercial process, invented by Wilhelm Ostwald, used to produce nitric acid. Ammonia is heated with a catalyst (platinum) to form nitric oxide that is then oxidized to yield nitrogen dioxide, which in turn reacts with water to yield nitric acid and nitric oxide:

2 NH₃ + 4 O₂ → 2 NO + 3 H₂O

2 NO + O₂ → 2 NO₂

4 NO₂ + O₂ + 2 H₂O → 4 HNO_3(aq)