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| Names | |
|---|---|
| IUPAC name Ammonium nitrite | |
| Identifiers | |
3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.033.257 |
| EC Number |
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| UNII | |
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| Properties | |
| [NH4]NO2 | |
| Molar mass | 64.044 g·mol−1 |
| Appearance | colorless or pale yellow crystals |
| Density | 1.69 g/cm3 |
| Melting point | Decomposes |
| 118.3 g / 100mL | |
| Explosive data | |
| Shock sensitivity | Low |
| Friction sensitivity | Low |
| Detonation velocity | >1000 m/s |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Explosive |
| GHS labelling: | |
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| Danger | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Non-flammable | |
| Related compounds | |
Otheranions | Ammonium nitrate |
Othercations | Sodium nitrite |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Ammonium nitrite is achemical compound with thechemical formula[NH4]NO2. It is theammonium salt ofnitrous acid. It is composed of ammoniumcations[NH4]+ andnitriteanionsNO−2. It is not used in pure isolated form since it is highly unstable and decomposes intowater andnitrogen, even at room temperature.
Ammonium nitrite forms naturally in the air and can be prepared by the absorption of equal partsnitrogen dioxide andnitric oxide in aqueousammonia.[1]
It can also be synthesized by oxidizing ammonia withozone orhydrogen peroxide, or in aprecipitation reaction of barium or lead nitrite withammonium sulfate, or silver nitrite withammonium chloride, orammonium perchlorate withpotassium nitrite. The precipitate is filtered off and the solution concentrated. It forms colorless crystals which are soluble in water.
Ammonium nitrite may explode at a temperature of 60–70 °C,[1] and will decompose quicker when dissolved in a concentrated aqueous solution, than in the form of a dry crystal. Even in room temperature the compound slowly decomposes into water and nitrogen:
It decomposes when heated or in the presence of acid into water and nitrogen.[2] Ammonium nitrite solution is stable at higherpH and lower temperature. If there is any decrease in pH lower than 7.0, it may lead to an explosion, since the nitrite can react to it. A safe pH can be maintained by adding an ammonia solution. The mole ratio of ammonium nitrite to ammonia must be above 10%.
