Nitric acid

Nitric-acid

Nitric acid

Nitric acid is a highly corrosive and strong oxidizing agent that is widely used in various industries for its versatile properties. It is available in two main forms: weak nitric acid and concentrated nitric acid.

Weak nitric acid, typically with a concentration of around 68-72% by weight, is commonly used in applications such as pickling and cleaning metals, etching printed circuit boards, and producing ammonium nitrate. It is milder in nature compared to concentrated nitric acid and is suitable for processes that require controlled and less aggressive reactions.

Concentrated nitric acid, with a minimum concentration of 98.5% by weight, is known as fuming nitric acid. It is a highly potent and reactive form of nitric acid used for various purposes, including nitrations, oxidations, and etching processes. Concentrated nitric acid is characterized by its yellowish color and pungent odor.

Property Concentrated Nitric Acid Weak Nitric Acid
HNO3 Concentration 98.5% by weight minimum 61.5 ± 0.5% by weight (68%, 72%)
Nitrous Oxide as HNO2 500 ppm maximum 500 ppm maximum
Chloride as Cl 10 ppm maximum 10 ppm maximum
Sulphate as H2SO4 50 ppm maximum
Arsenic as As 2 ppm maximum
Residue on Ignition 500 ppm maximum 100 ppm maximum
Heavy Metal as Pb To pass the test To pass the test
Specific Gravity 1.5 at 25°C 1.368 at 25°C
CAS Number 7697-37-2 7697-37-2
UN Number 2031 2031