When potassium nitrate is heated it produce potassium nitrite and nitrogen (IV) oxide gas

The first step in the industrial manufacture of nitric acid is the catalytic oxidation of ammonia gas

Nitric (V) acid react with all metals to produce hydrogen gas

Nitric (V) acid is stored in dark bottles becase it is decomposed by light.

Iron  is used as a catalsyt in the large scale manufacture of nitric (V) acid