Ammonium nitrate
The chemical compound ammonium nitrate, the nitrate of ammonium with chemical formula NH4NO3, is commonly used in agriculture as a high-nitrogen fertilizer. As a strong oxidizing agent, it has applications as a component of explosives. In the latter use, it is usually mixed with oil. Because of the ready availability in bulk of the raw materials, Ammonium nitrate/fuel oil (ANFO) mixtures have occasionally been used for terrorist bombs, such as in the Oklahoma City bombing.
Ammonium nitrate decomposes into gases including oxygen when heated (non-explosive reaction); however, ammonium nitrate can be induced to decompose explosively by detonation. Large stockpiles of the material can be a major fire risk due to their supporting oxidation, and may also detonate, as happened in the Texas City disaster[?] of 1947, which led to major changes in the regulations for storage and handling.
Another heavy explosion occurred in the city of Oppau (Germany) on September 21. 1921.
Ammonium Nitrate is also used in instant cold packs, as it dissolves in water endothermically, absorbing 26.2 kilojoules per mole of heat to do so.
General
Name
Ammonium nitrate
Chemical formula
NH4NO3
Appearance
White solid
Physical
Formula weight
80.0 amu
Melting point
442 K (169 °C)
Boiling point
decomposes at 483 K (210 °C)
Density
1.7 ×103 kg/m3
Crystal structure
?
Solubility
208 g in 100g water
Thermochemistry
ΔfH0liquid
-359.6 kJ/mol
ΔfH0solid
-366 kJ/mol
S0liquid, 1 bar
? J/mol·K
S0solid
151 J/mol·K
Safety
Ingestion
Dangerous in large quantities.
Inhalation
Very dangerous - can be fatal.
Skin
May cause irritation.
Eyes
May cause irritation.
More info
Hazardous Chemical Database (http://ull.chemistry.uakron.edu/erd/chemicals/7/6028.html)
SI units were used where possible. Unless otherwise stated, standard conditions were used.