LAQ : How HNO3 is manufactured by Ostwalds process? 

Question

How HNO₃ is manufactured by Ostwald’s process? 

Answer

HNO₃ is manufactured by Ostwald’s Process, which involves the following steps:

1. Ammonia (NH₃) is oxidized to nitrogen monoxide (NO) by heating it in the presence of a platinum-rhodium catalyst at a temperature of around 850-900°C.
   4NH₃ (g) + 5O₂ (g) → 4NO (g) + 6H₂O (g)

2. The nitrogen monoxide is then oxidized to nitrogen dioxide (NO2) by reacting it with excess oxygen in the presence of a platinum-rhodium catalyst at a temperature of around 450-550°C.
   2NO (g) + O₂ (g) → 2NO₂ (g)

3. The nitrogen dioxide is then absorbed in water to form nitric acid (HNO₃), which is then concentrated to the desired strength through distillation.
   3NO₂ (g) + H₂O (l) → 2HNO₃ (aq) + NO (g)