Question

explain catalytic oxidation of ammonia.

Answer 1

In the presence of Platinum at 800°C, ammonia reacts with oxygen to give nitric oxide and water vapour.
Procedure:
Pass dry ammonia gas and oxygen gas through inlets over heated platinum placed in the combustion tube, which in the heated state emits reddish glow.
Reaction:
4NH₃+ 5O₂  4NO + 6H₂O + Heat
2NO + O₂ → 2NO₂
Brown gas
Observation:
Reddish brown vapours of nitrogen dioxide are seen in the flask due to the oxidation of nitric oxide.
The platinum continues to glow even after the heating is discontinued since the catalytic oxidation of ammonia is exothermic.