Manufacturing Nitric Acid
The process is called the OSTWALD PROCESS.
It involves three steps.
Step 1
Ammonia is:
- mixed with air
- heated
- compressed
- and passed over platinum plates (catalysts)
4NH3 + 5O2 → 4NO + 6H2O
Step 2
Nitrogen monoxide is oxidised into nitrogen dioxide
2NO + O2 → 2NO2
Step 3
Nitrogen dioxide is absorbed in water, forming nitric acid.
3NO2 + H2O → 2HNO3 + NO
The overall reaction is :
NH3 + 2O2 → HNO3 + H2O
Some Uses of HNO3
The nitric acid is used to make:
- ammonium nitrate (NH4NO3) which is used in fertilisers
- nylon
- explosives
- nitrates for medicinal and industrial use
- plastics and dyes.
