Sodium hydride

Off-white crystals

Fixed

1.36 g · cm -3

Decomposition from 425 ° C

Reacts violently with water

Risk

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Production and representation

It is prepared industrially at 250-300 ° C by passing pure hydrogen gas over molten sodium. Neither water nor oxygen must be present.

Properties

Sodium hydride is an ionic salt-like compound: It has the structure of an ion grid which is similar to the sodium chloride structure. On contact with water, it reacts violently to sodium hydroxide and molecular hydrogen, which is flammable. As a protection against humidity sodium hydride is usually sold as a mixture of 60 % NaH in paraffin oil or petroleum ether.

Sodium hydride is a strong base ( Brønsted by the hydride ion, the base ), which is used mainly in organic synthesis since it is able to deprotonate and weak acids such as alcohols. Furthermore sodium hydride is used as reducing agent, for example, of disulfides to thiols gain.