Ammonium azide
| Names | |
|---|---|
| IUPAC name
Ammonium azide
| |
| Other names
Ammonium trinitride
Azanium azide | |
| Properties | |
| NH4N3 | |
| Molar mass | 60.059 g/mol |
| Appearance | White crystalline solid |
| Odor | Odorless |
| Density | 1.3459 g/cm3 (at 20 °C) |
| Melting point | 160 °C (320 °F; 433 K) |
| Boiling point | 400 °C (752 °F; 673 K) (decomposes) |
| Soluble | |
| Solubility | Soluble in anh. ammonia Insoluble in esters, ethers, hydrocarbons |
| Vapor pressure | 0.2 mmHg (at 15 °C)[1] |
| Thermochemistry | |
| Std enthalpy of
formation (ΔfH |
113.2 - 115 kJ·mol−1 140.4 - 142.3 kJ·mol−1[2] |
| Hazards | |
| Flash point | Detonates above 100 °C |
| Related compounds | |
| Related compounds
|
Sodium azide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Ammonium azide is an explosive chemical compound with the formula NH4N3.
Ammonium azide is one of the few oxygen-free explosive materials that can be handled (relatively) safely.
Contents
Properties
Chemical
Ammonium azide will detonate to release nitrogen and hydrogen gases.
- NH4N3 → 2 N2 + 2 H2
Traces of ammonia are also produced.
Physical
Ammonium azide is a non-hygroscopic colorless odorless crystalline solid. It melts at 160 °C and decomposes at 400 °C. Ammonium azide is soluble in water. It also is soluble in ammonia. It is also easily soluble in ethanol, glycerol, methanol, pyridine, sparingly soluble in allyl alcohol, butanol and isobutanol and insoluble in acetone, aniline, benzaldehyde, benzene, carbon disulfide, chlorobenzene, chloroform, diethyl ether, ethyl acetate, isoamyl alcohol, methyl acetate, methyl ethyl ketone, nitrobenzene, tetrachloroethane, toluene and xylene.[3]
Explosive
Ammonium azide has relative low shock sensitivity and is stable when heated to drying at 100 °C.[4] Strong heating will cause it to break down to ammonia and hydrazoic acid, the latter being the one that detonates. Due to its low shock sensitivity, ammonium azide can be safely ground in a wooden mortar.[5] It will also detonate under strong shock and in contact with some metals, such as copper.
Availability
Ammonium azide is not sold by any supplier and has to be made in situ.
Preparation
Ammonium azide can be made by bubbling anhydrous ammonia in a ether solution of HN3. Since ammonium azide is almost insoluble in ether, it will precipitate. The precipitate is filtered and vacuum dried. Water traces are removed using phosphorus pentoxide in a desiccator.
Heating a mixture of sodium azide with ammonium nitrate in a stream of dry air in a tube at 190 °C for 30 min will yield ammonium azide. The yield of the process is 93%. Ammonium sulfate can also be used instead of nitrate.[6]
Projects
- Make exotic azides
Handling
Safety
Ammonium azide is explosive and toxic.
Storage
Should only be stored in closed bottles in cold places for short periods of time, as it will slowly sublime away.
Disposal
Can be neutralized with nitrous acid or acidified sodium nitrite.
Bleach can also be used, though it's best to precipitate the azide first with a base, since ammonium ions may react with bleach to form chloramines.[7]
References
- ↑ Frost; Cothran; Browne; Journal of the American Chemical Society; vol. 55; (1933); p. 3516
- ↑ Finch, Arthur; Gardner, P. J.; Head, A. J.; Xiaoping, Wu; Journal of Chemical Thermodynamics; vol. 22; nb. 3; (1990); p. 301 - 305
- ↑ Frost; Cothran; Browne; Journal of the American Chemical Society; vol. 55; (1933); p. 3516
- ↑ Reckeweg, Olaf; Simon, Arndt; Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences; vol. 58; nb. 11; (2003); p. 1097 - 1104
- ↑ Yakovleva, G. S.; Kurbangalina, R. Kh.; Stesik, L. N. (1977), Combustion, Explosion, and Shock Waves, Detonation properties of ammonium azide, 13 (3), p. 405
- ↑ Frierson, W. J.; Browne, A. W.; Journal of the American Chemical Society; vol. 56; (1934); p. 2384
- ↑ https://www.ncbi.nlm.nih.gov/m/pubmed/20667654/
