Lithium hydride (LiH) (also known as lithium deuteride, when the deuterium isotope of hydrogen is used for the hydrogen component) is a compound of lithium and hydrogen.

It is a white to grey, translucent, odorless, crystalline solid, with a melting point of 689 degrees Celsius (1272 degrees Fahrenheit), and a density of 780 kilograms per cubic metre.

It is a flammable solid, and is also very reactive to water, with which it reacts to produce lithium hydroxide (which is a corrosive strong alkali compound), and flammable hydrogen gas. It may ignite spontaneously in air, when at an elevated temperature.

Synthesis

It is produced by reacting lithium metal directly with hydrogen gas to form lithium hydride:

2Li + H₂ $\backslash rightarrow$ 2LiH

Uses

It has numerous uses, as a desiccant, among them as a precursor in chemical synthesis (in particular for lithium aluminium hydride), in hydrogen generators, as both a coolant and shielding in nuclear reactors, and in the manufacture of ceramics.

One of its most infamous usages is as the fusion fuel in thermonuclear weapons, in the deuteride form; when this is irradiated with neutrons, lithium forms tritium (along with more neutrons, creating a chain reaction), which is a key ingredient in the thermonuclear reactions which power these devices.

See also

• Hydride

Related compounds

• Sodium hydride

External links

• Compounds of lithium: Lithium (I) Hydride
• Emergency First Aid Treatment Guide - Lithium Hydride
• Computational Chemistry Wiki

Lithium compounds | Metal hydrides | Desiccants | Nuclear materials

Lithiumhydrid | Lithiumhydride