How Nitric Acid is Made
Published by Nitric acid can be made in different ways.
Nitric acid is a strong acid which is also poisonous and corrosive. A strong acid is one that is completely ionised in solution and is not related to its concentration. It is important that nitric acid is stored at temperatures lower than 0°C else it decomposes into nitrogen dioxide, oxygen and water.
Nitric acid used to be produced industrially via the arc process (Birkeland–Eyde Process) which involved an electric discharge being passed through the air. The nitrogen and oxygen in the air were atomised and reacted together to form nitrogen monoxide. Once cooled the nitrogen monoxide was mixed with more air which gave nitrogen dioxide. The nitrogen dioxide was passed through water to produce nitric acid. So much electricity was required by this process that it had to be powered by a hydroelectric power station.
The Ostwald Process is used now to make nitric acid industrially. It involves oxidising ammonia (from the Haber Process) by heating in oxygen in the presence of a platinum catalyst, at a temperature of about 900°C and a pressure of about 5 atmospheres. The nitrogen monoxide produced is mixed with more oxygen to make nitrogen dioxide. The nitrogen dioxide is absorbed into water to produce hot dilute nitric acid and some nitrogen monoxide is also liberated which is recycled back in the process.
Nitric acid can be made in a laboratory by mixing concentrated sulphuric acid with a nitrate salt. Sulphuric acid, being more acidic than nitric acid donates its protons, thereby forming nitric acid and the corresponding bisulphate salt.
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On September 28, 2010 at 6:24 am
wow, superb creating the yellowing liquid