Ammonium Nitrate

Title: Ammonium Nitrate
CAS Registry Number: 6484-52-2
Molecular Formula: H4N2O3
Molecular Weight: 80.04
Percent Composition: H 5.04%, N 35.00%, O 59.97%
Line Formula: NH4NO3
Literature References: Manuf: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 97-102. Comprehensive description of manuf processes and physical data: B. T. Federoff et al., Encyclopedia of Explosives and Related Items vol. I (Picatinny Arsenal, Dover, N.J., 1960) pp A311-A379. Review: Thatcher, "Ammonium Nitrate" in Mellor's vol. VIII, supplement I, Nitrogen (part 1) 506-562 (1964).
Properties: Odorless, transparent, hygroscopic, deliquesc crystals or white granules. Five solid phases exist at normal pressure. Orthorhombic at room temp. d 1.72. Dec at about 210°, mostly into H2O and N2O. 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. Keep well closed.
Density: d 1.72
NOTE: Disastrous explosions ascribed to ammonium nitrate occurred in 1947 at Texas City and at Brest.
Use: Making nitrous oxide (laughing gas); in freezing mixtures, safety explosives, matches; pyrotechnics; in fertilizers.
Therap-Cat-Vet: Has been used as an expectorant, urinary acidifier.
Ammonium Nitroferricyanide Ammonium Oleate Ammonium Osmium Chloride Ammonium Oxalate Ammonium Palmitate

Ammonium nitrate
Structural formula
Ammonium nitrate crystal structure
Sample of white powder
CAS number 6484-52-2 YesY
ChemSpider 21511 YesY
UN number 0222 – with > 0.2% combustible substances
1942 – with <= 0.2% combustible substances
2067 – fertilizers
2426 – liquid
RTECS number BR9050000
Jmol-3D images Image 1
Molecular formula (NH4)(NO3)
Molar mass 80.052 g/mol
Appearance white/grey solid
Density 1.725 g/cm3 (20 °C)
Melting point 169.6 °C
Boiling point approx. 210 °C decomp.
Solubility in water 118 g/100 ml (0 °C)
150 g/100 ml (20 °C)
297 g/100 ml (40 °C)
410 g/100 ml (60 °C)
576 g/100 ml (80 °C)
1024 g/100 ml (100 °C)[1]
Crystal structure trigonal
Explosive data
Shock sensitivity very low
Friction sensitivity very low
Explosive velocity 5270 m/s
EU Index not listed
Main hazards Explosive
NFPA 704
NFPA 704.svg
LD50 2085–5300 mg/kg (oral in rats, mice)[2]
Related compounds
Other anions Ammonium nitrite
Other cations Sodium nitrate
Potassium nitrate
Hydroxylammonium nitrate
Related compounds Ammonium perchlorate
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

The chemical compound ammonium nitrate, the nitrate of ammonia with the chemical formula NH4NO3, is a white crystalline solid at room temperature and standard pressure. It is commonly used in agriculture as a high-nitrogen fertilizer, and it has also been used as an oxidizing agent in explosives, including improvised explosive devices. It is the main component of ANFO, a popular explosive, which accounts for 80% explosives used in North America. It is used in instant cold packs, as hydrating the salt is an endothermic process.

Ammonium nitrate is found as a natural mineral (ammonia nitre—the ammonium analogue of saltpetre and other nitre minerals like sodium nitrate) in the driest regions of the Atacama Desert in Chile, often as a crust on the ground and/or in conjunction with other nitrate, chlorate, iodate, and halide minerals. Ammonium nitrate was mined there in the past, but virtually 100 per cent of the chemical now used is synthetic.