Sulfuric Acid, Nitrogen-free

Sulphuric acid, nitrogen-free

Complies with the requirements prescribed for sulfuric acid with the following additional test.

Nitrates. To 5 mL of water add carefully 45 mL of the sulfuric acid, allow to cool to 40 °C and add 8 mg of diphenylbenzidine. The solution is colourless or very pale blue.