| Urea nitrate | |
|---|---|
| Properties | |
| Molecular formula | CH5N3O4 |
| Molar mass | 123.068 g/mol |
| Density | 1.59 g/cc |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Urea nitrate is a fertilizer-based high explosive that has been used in improvised explosive devices in Israel, Iraq, and various other terrorism acts elsewhere in the world, like the 1993 World Trade Center bombings.[1] It has a destructive power similar to better-known ammonium nitrate explosives, with a velocity of detonation between 11,155 ft/s (3,400 m/s) and 15,420 ft/s (4,700 m/s).[2]
Production is by nitration of urea using nitric acid. This is an exothermic reaction, so steps must be taken to control the temperature. Presence of sulfuric acid during the nitration catalyzes the reaction, although this is not necessary. [2]
Urea nitrate explosions may be initiated using a blasting cap. [2]
Urea contains a carbonyl group. The more electronegative oxygen atom pulls electrons away from the carbon forming a greater electron density around the oxygen, giving the oxygen a partial negative charge and forming a polar bond. When nitric acid is presented, it ionizes. A hydrogen ion [proton] contributed by the acid is attracted to the oxygen and forms a covalent bond [electrophile H+]. The electronegative NO3- ion then is attracted to the positive hydrogen ion. This forms an ionic bond and hence the compound urea nitrate. As an ionic compound urea nitrate is highly soluble in water.
(NH2)2CO (aq) + HNO3 (aq) → (NH2)2COHNO3 (s)
The compound is favored by many amateur explosive enthusiasts as a principal explosive for use in larger charges. In this role it acts as a substitute for ammonium nitrate based explosives. 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.