Lithium azide
| Names | |
|---|---|
| IUPAC name
Lithium azide
| |
| Other names
Lithium triazide
| |
| Properties | |
| LiN3 | |
| Molar mass | 48.96 g/mol |
| Appearance | Colorless solid |
| Odor | Odorless |
| Melting point | 115 °C (239 °F; 388 K) (decomposes) |
| Boiling point | 298 °C (568 °F; 571 K) (explodes) |
| 36.12 g/100 ml (10 °C) 62.07 g/100 ml (15.5 °C) 66.41 g/100 ml (16 °C)[1] | |
| Solubility | Reacts with acids Soluble in ethanol, hydrazine, methanol Insoluble in diethyl ether |
| Solubility in ethanol | 20.26 g/100 ml (16 °C) |
| Vapor pressure | ~0 mmHg |
| Hazards | |
| Safety data sheet | Sigma-Aldrich (20% aq. solution) |
| Related compounds | |
| Related compounds
|
Sodium azide Potassium azide Rubidium azide Caesium azide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Lithium azide is the lithium salt of hydrazoic acid, with the chemical formula LiN3.
Contents
Properties
Chemical
Lithium azide decomposes when heated.
Physical
Lithium azide is a colorless crystalline solid, soluble in water. The compound can be encountered as a monohydrate between -31 °C and 68 °C, and above this temperature, the compound exists only as anhydrous.[2]
Explosive
Lithium azide has been characterized as being explosive. If heated rapidly above 115 °C it will violently decompose, but its decomposition can be delayed until 298 °C if heated slowly.[3] It has a reported detonation velocity of 990 m/s.
Availability
Lithium azide is sold by chemical suppliers, albeit only as solution.
Due to the high toxicity of azides, it is not generally available for the public.
Preparation
It can be prepared by metathesis reaction between sodium azide and lithium nitrate or lithium sulfate solutions:[4]
- NaN3 + LiNO3 → LiN3 + NaNO3
- 2 NaN3 + Li2SO4 → 2 LiN3 + Na2SO4
It can also be prepared by reacting lithium sulfate with barium azide. Barium sulfate precipitates out of the solution and after filtering, the solution is slowly evaporated to obtain the pure lithium azide.
- Ba(N3)2 + Li2SO4 → 2 LiN3 + BaSO4
Very pure lithium azide can be obtained by neutralizing lithium carbonate with hydrazoic acid.
Projects
- Azidation agent
- Make other azide salts
Handling
Safety
Lithium azide is extremely toxic. The toxicity of azides is similar that of cyanides. There is no known antidote.
Storage
Lithium azide should be stored in spark-free containers, away from moisture or any acidic vapors.
Disposal
When disposed of, it must never be poured down the drain, as it will react to either copper or lead plumbing to yield copper azide, which is highly sensitive. Hydrolysis can also occur in aqueous solutions, at certain pH. Lithium azide must be treated with nitrous acid before being discarded. This can be easily obtained by acidifying sodium nitrite.
References
- ↑ https://aip.scitation.org/doi/10.1063/1.1563591
- ↑ A. P. Rollet, J. Wohlgemuth, Compt. Rend., 198, 1772 (1934)
- ↑ Fair H.D, Walker R.F. (ed.) - Energetic Materials. Physics and Chemistry of Inorganic Azides. 1-Plenum Press (1977)
- ↑ http://www.lambdasyn.org/synfiles/lithiumazid.htm
