Difference between revisions of "Lithium hydride"
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Lithium hydride is sold by chemical suppliers, though it's not cheap.
Lithium hydride is sold by chemical suppliers, though it's not cheap
Revision as of 19:45, 8 October 2019
| IUPAC name
| Other names
|Molar mass||7.95 g/mol|
|Appearance||White or light gray samples|
|Melting point||688.7 °C (1,271.7 °F; 961.9 K)|
|Boiling point||900 °C (1,650 °F; 1,170 K) (decomposes)|
|Solubility|| Reacts with alcohols, aldehydes, amines, ammonia, carboxylic acids, DMSO, esters, ethers, halocarbons, ketones|
Soluble in molten lithium borohydride, lithium fluoride and sodium hydride
Slightly soluble in dimethylformamide
Insoluble in hydrocarbons
|Vapor pressure||~0 mmHg|
Std enthalpy of
|Safety data sheet||Sigma-Aldrich|
| Sodium hydride|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Lithium hydride is an inorganic compound with the formula LiH.
Lithium hydride reacts with water to release hydrogen.
- LiH + H2O → LiOH + H2
Lithium hydride is an odorless white or slight grayish solid, which reacts with most solvents and is insoluble in those with which it doesn't react, like hydrocarbons.
Lithium hydride is sold by chemical suppliers, though it's not cheap, and it's hard to find.
On Alibaba one can find many sellers selling what is described as "lihium hydride", but be very careful if you want to purchase the product from there, since most of the prices listed for this compound are very low, which may be suspicious, since lithium compounds aren't cheap, let alone a hydrogen-rich and potentially pyrophoric powdered lithium compound.
Can be prepared by reacting molten lithium metal with hydrogen. The reaction takes place in a nickel crucible, between 450-500 °C, and the hydrogen used must be air and water-free. The yield of this reaction is 95%.
However, the reaction can proceed at temperatures as low as 29 °C. The yield is 60% at 99 °C and 85% at 125 °C, and the rate depends significantly on the surface condition of LiH and the purity of the inert gas used as inert conditions.
Hydrogenolysis of n-butyllithium at normal temperature and atmospheric pressure in the absence of catalyst will yield LiH.
- Make lithium aluminium hydride
Lithium hydride is very reactive towards most common solvents, it will even slowly attack ethers. It may spontaneously ignite in moist air.
Lithium hydride must be kept in air-tight containers, in an inert atmosphere, away from moisture. Schlenk flasks are good storage containers.
Lithium hydride can be safely neutralized by slowly adding it in a large volume of alcohol, followed by slow addition of water.
- Brandt, P.; Acta Chemica Scandinavica (1947-1973); vol. 3; (1949); p. 1050 - 1057
- Gilman, H.; Jacoby, A. L.; Ludeman, H.; Journal of the American Chemical Society; vol. 60; (1938); p. 2336 - 2338