The Formation Of Nitric Acid From Ammonia

Nitric acid (HNO3) is made from ammonia (NH3).

The reaction happens in three stages:

1. Ammonia and oxygen from the air are reacted together to make nitrogen monoxide and water.

They are heated to 300 0C and passed over a catalyst of platinum (other catalyst'shave been used). (A catalyst speeds up a chemical reaction without itself being changed).

The reaction makes its own heat (exothermic) and is cooled down by using more air than is needed to react with the ammonia.

4NH3 + 5O2 --------> 4 NO + 6 H2O

ammonia + oxygen -----------> nitrogen monoxide + water

2. The nitrogen monoxide is reacted with more oxygen from the air to make nitrogen dioxide which is a brown poisonous gas.

2 NO + O2----------> 2NO2

nitrogen monoxide + oxygen ---------->nitrogen dioxide

3. The nitrogen dioxide is dissolved in water in the presence of air to make nitric acid.

4NO2 + O2 + 2 H2O----------> 4HNO3

nitrogen dioxide + oxygen + water---------> nitric acid