NITRIC acid is a colourless liquid with a suffocating odour. It is highly caustic and corrosive and can cause severe and painful burns on the skin.
This strong, inorganic acid has many industrial uses, principally in the production of fertilisers, drugs and explosives.
It is such a powerful oxidising agent that it can dissolve many metals, although it does not affect gold and platinum. As such, it was used to test whether jewellery purportedly made from these precious metals was genuine.
The chemical industry uses nitric acid to prepare dyes, drugs and nitrate salts. Nitric acid reacts with toluene in the presence of sulphuric acid to form trinitrotoluene, otherwise known as the explosive TNT.
Cellulose is treated with nitric acid to make cellulose nitrate for guncotton and other explosives.
Commercially, most nitric acid is produced by oxidising ammonia using a platinum catalyst. Ammonia and air are passed through heated platinum gauze. The gases react to form nitrogen oxide and water. Upon cooling, this gaseous mixture forms nitric acid.