Chemistry:Urea nitrate
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3D model (JSmol)
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PubChem CID
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| Properties[2] | |
| (NH 2) 2COHNO 3 | |
| Molar mass | 123.068 g·mol−1 |
| Appearance | Colorless monoclinic leaflets[1] |
| Density | 1.67±0.011 g/cm3 |
| Melting point | 157–159 °C (315–318 °F; 430–432 K) |
| 167.2±0.5 mg/mL | |
| Solubility in Ethanol | 14.2±0.1 mg/mL |
| Solubility in Acetone | 10.4±0.2 mg/mL |
| Solubility in Methanol | 54.8±0.9 mg/mL |
| Thermochemistry[1] | |
Std enthalpy of
formation (ΔfH⦵298) |
1090 kcal/kg |
Std enthalpy of
combustion (ΔcH⦵298) |
1071.7 cal/g |
| Structure[3] | |
| Monoclinic | |
| P21/c | |
a = 9.527±0.007 Å, b = 8.203±0.005 Å, c = 7.523±0.006 Å α = 90°, β = 124.37±0.05°, γ = 90°
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Formula units (Z)
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4 |
| Explosive data[1] | |
| Shock sensitivity | Insensitive, up to 49 N⋅m with no reaction. |
| Friction sensitivity | Insensitive |
| Detonation velocity |
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| RE factor |
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| Hazards | |
| GHS pictograms |    [4]
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| GHS Signal word | Danger |
| H228, H319 | |
| P210, P240, P241, P264, P280, P370+378, P305+351+338 | |
| Flash point | 72.7 °C (162.9 °F; 345.8 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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| Infobox references | |
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Urea nitrate is a fertilizer-based high explosive with the chemical formula of CH
5N
3O
4 (or (NH
2)
2COHNO
3) that has been used in improvised explosive devices in Afghanistan, Pakistan, Iraq, and various terrorist acts elsewhere in the world such as in the 1993 World Trade Center bombings.[6]
Synthesis
Urea nitrate is produced in one step by reaction of urea with nitric acid. This is an exothermic reaction, so steps must be taken to control the temperature.
Chemistry
Urea contains a carbonyl group. The more electronegative oxygen atom pulls electrons away from the carbon atom, forming a polar bond with greater electron density around the oxygen atom, giving it a partial negative charge. In a simplistic sense, nitric acid dissociates in aqueous solution into protons (hydrogen cations) and nitrate anions. The electrophilic proton contributed by the acid is attracted to the negatively charged oxygen atom on the urea molecule and the two form a covalent bond. Paired with the spectator nitrate counteranion, it forms urea nitrate.Template:Overexplained
- (NH
2)
2CO(aq) + HNO
3(aq) → [(NH
2)
2COH]+
[NO
3]−
(s)
History
It was discovered in 1797 by William Cruickshank, inventor of the Chloralkali process.[7]
Explosive properties
It has a destructive power similar to better-known ammonium nitrate explosives, with a velocity of detonation between 3,400 m/s (11,155 ft/s) and 4,700 m/s (15,420 ft/s). Urea nitrate must be initiated using a blasting cap.[8][1]
The compound has frequently been used by terrorist and criminal groups due to its ease of production and low skill level required for synthesis. This is due to the ease of acquiring the materials necessary to synthesize it, and its greater sensitivity to initiation compared to ammonium nitrate based explosives.[9][10]
References
- ↑ 1.0 1.1 1.2 1.3 Kaye, Seymour M.; Henry L., Herman (January 1983). "U - Urea Addition Compounds and Salts - Urea Nitrate". Encyclopedia of Explosives and Related Items (PDF) (Technical report). Vol. 10, U.D.C. through Z-Salz. Picatinny Arsenal, Dover, NJ: U.S. Army Research and Development Command TACOM - Ardec Warheads, Energetics and Combat Support Center. pp. U102-3. LCCN 61-61759. ADA134347, PATR 2700.
- ↑ Oxley, Jimmie C.; Smith, James L.; Vadlamannati, Sravanthi; Brown, Austin C.; Zhang, Guang; Swanson, Devon S.; Canino, Jonathan (2013). "Synthesis and Characterization of Urea Nitrate and Nitrourea". Propellants, Explosives, Pyrotechnics 38 (3): 335-44. doi:10.1002/prep.201200178. https://energetics.chm.uri.edu/system/files/UN%20and%20NU.pdf.
- ↑ Harkema, S.; Feil, D. (1 March 1969). "The crystal structure of urea nitrate". Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry 25 (3): 589–591. doi:10.1107/S0567740869002603.
- ↑ "SDS - Urea Nitrate (wetted)". TCI America. 13 December 2006. https://cloudfront.zoro.com/enhanced_pdf/ZQ_7nLhegt.PDF.
- ↑ "Urea nitrate SDS". ECHEMI. 15 July 2019. https://www.echemi.com/sds/ureanitrate-pid_Seven3850.html.
- ↑ Aaron Rowe (18 September 2007). "Chem Lab: Spray-On Test for Improvised Explosives". Wired. http://blog.wired.com/wiredscience/2007/09/spray-on-test-f.html.
- ↑ Rosenfeld, Louis (1999) (in en). Four Centuries of Clinical Chemistry. CRC Press. ISBN 978-90-5699-645-1. https://books.google.com/books?id=KPX6Yvax9jkC&pg=PA40.
- ↑ "Explosives - ANFO (Ammonium Nitrate - Fuel Oil)". GlobalSecurity.org. https://www.globalsecurity.org/military/systems/munitions/explosives-anfo.htm.
- ↑ D'Uva, Joshua A.; DeTata, David; Fillingham, Ryan; Dunsmore, Robert; Lewis, Simon W. (December 2021). "Synthesis and characterisation of homemade urea nitrate explosive from commercial sources of urea" (in en). Forensic Chemistry 26. doi:10.1016/j.forc.2021.100369.
- ↑ Tamiri, Tsippy; Rozin, Rinat; Lemberger, Nitay; Almog, Joseph (September 2009). "Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization". Analytical and Bioanalytical Chemistry 395 (2): 421–428. doi:10.1007/s00216-009-2882-x. PMID 19575193.
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