Question

1. Name the process used for the manufacture of nitric acid.
2. What are the reactants required for it and what are their sources?
3. In which ratio reactants are taken in this process?
4. Name the catalyst used in the process.
5. What is the oxidizing agent in this process?
6. Write the equations involved.

Answer 1

1. Ostwald process
2. The reactants are ammonia and air. Ammonia is obtained from the Haber process, while air is obtained from the atmosphere.
3. Ammonia and air are mixed in the ratio 1 : 10.
4. Platinum gauze or platinum-rhodium gauze is used as the catalyst.
5. Oxygen present in air acts as the oxidising agent.
6. Catalytic oxidation of ammonia:
   \[\ce{4NH3 + 5O2 ->[Pt{.}, 800^\circ C] 4NO + 6H2O}\]
   Oxidation of nitric oxide:
   \[\ce{2NO + O2 -> 2NO2}\]
   Absorption of nitrogen dioxide in water:
   \[\ce{3NO2 + H2O -> 2HNO3 + NO}\]
   Thus, the Ostwald process manufactures nitric acid industrially.