534. Ammonium Nitrate

Nomenclature

CAS number: 6484-52-2
Nitric acid ammonium salt (1:1); Norway saltpeter.
H4N2O3; mol wt 80.04.
H 5.04%, N 35.00%, O 59.97%.
NH4NO3.

Description and references

First prepd in 1659 by reaction of ammonium carbonate with nitric acid. Review of uses in explosives and fertilizers, and physical properties: K. D. Shah, A. G. Roberts in Nitric Acid and Fertilizer Nitrates, C. Keleti, Ed. (Marcel Dekker, New York, 1985) pp 165-169, 171-196; of industrial production: G. D. Honti, ibid. pp 197-223; of use as a solid propellant oxidizer: C. Oommen, S. R. Jain, J. Hazard. Mater. A67, 253-281 (1999).

Properties

Odorless, transparent, hygroscopic, deliquesc crystals or white granules, mp 169.6°. Dec begins above 170°. Five solid phases exist at normal pressure. Orthorhombic at room temp. Oxidizer in hot concentrated solns. Closed containers may rupture violently when heated. d 1.725. One gram dissolves in 0.5 ml water, 0.1 ml boil. water, about 20 ml alc, about 8 ml methanol, pH of 0.1M soln in water: 5.43. Sol in anhydrous and aq ammonia, aq nitric acid, acetic acid.

Use

Major component in manuf of industrial and military explosives; in matches, pyrotechnics. In fertilizers; freezing mixtures. In manuf of nitrous oxide (laughing gas). When dissolved in liq NH3 (Divers soln), used to strip ammonia from gases. Clean burning propellant oxidizer.