Ethyl nitrate
Salpetersäureethylester
Colorless, pleasant -smelling liquid
Liquid
1.11 g · cm -3
-112 ° C
88 ° C.
66.5 hPa ( 20 ° C)
Practically insoluble in water
1.3852 (20 ° C)
Risk
-190.4 KJ / mol
Template: Infobox chemical / molecular formula search available
Ethyl nitrate, nitric acid ester of ethanol, is a transparent high -explosive liquid with a pleasant odor.
Natural Occurrence
According to research from the University of East Anglia ethyl nitrate comes in addition to the artificial production also biogenic. Origin have a high probability of aquatic bacteria
Representation
Ethyl nitrate is formed under the action of concentrated, nitric oxide- free nitric acid to ethanol. The esterification reaction is exothermic with a molar heat of reaction of -25.9 kJ · mol -1. To isolate the resulting ethyl nitrate, it must be carefully distilled off. The production of ethyl nitrate is indeed remarkably simple and inexpensive, but also very dangerous, because the ethyl nitrate needs to be cleaned in the gas state in which it is highly explosive, transferred.
To prevent that by a side reaction takes place oxidation of ethanol, even the smallest traces of nitrous acid by the addition of urea nitrate must be removed. Otherwise, it may result in autocatalytic extending reaction that can proceed explosively.
Properties
Ethyl nitrate has a boiling point of 88 ° C under normal pressure, and is heavier than water. The vapor pressure function is given by Antoine corresponding log10 (P) = A- ( B / ( T C)) (P in Torr, T in ° C) with A = 7.145, B = 1329 and C = 224.0 in the temperature range of 0 ° C to 88 ° C. The molar enthalpy of vaporization at boiling point is 33.9 kJ · mol -1 at 25 ° C and 36.4 kJ mol -1. With water boiling at 74.35 ° C azeotrope is formed. The azeotrope composition is 22 % by mass of water and 78 % by mass of ethyl nitrate. The compound forms flammable vapor - air mixtures. It has a flash point of 10 ° C. The lower explosive limit (LEL) is 3.8 % by volume (140 g/m3). An upper explosive limit ( UEL) can not be determined due to the spontaneous decomposition of the compound. The vapors are Ethylnitrates as that of the closely related chemically, methyl nitrate, even the absence of air explosive, which carries a high risk potential in conjunction with the large volatility of the substances. It is similar shock sensitive as nitroglycerin, but this is inferior to the explosive force. Since there is not enough oxygen atoms in the molecule, in order to completely oxidize the available carbon and hydrogen atoms, it has a negative oxygen balance. Therefore, the resulting from the detonation fumes contain flammable gases such as hydrogen and carbon monoxide. For complete combustion oxygen must be added:
The heat of combustion of -1355.8 kJ · mol -1.
Explosion characteristics
- Heat of explosion: 4133 kJ · kg -1 (H2O ( l) ), 3739 kJ · kg -1 (H2O ( g)).
- Detonation velocity: 5800 m · s -1 at a density of 1.1 g · cm -3
- Normal gas volume: 1228 l · kg -1.
- Specific energy: 1108 kJ · kg -1
- Lead block expansion: 420 cm 3/ 10 g
Use
Ethyl nitrate is little commercial use, for example to increase the cetane number in diesel fuels ( similar to others used for this is alkyl nitrates ). In pure form, it is weaker and less safe to handle than nitroglycerin. However, it is often manufactured illegally due to the ready availability of the starting materials and used by terrorists. Will it be used as an explosive, so it is often mixed with oxidizing substances such as ammonium nitrate, to compensate for the oxygen balance and optimum use of the explosive power of the substance.