3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||40.1062 g/mol|
|Melting point||decomposes at ~400 °C|
|Solubility||insoluble in benzene, diethyl ether, CS2|
|Fm3m, No. 225|
Heat capacity (C)
|37.91 J/(mol K)|
Std enthalpy of
|Occupational safety and health (OHS/OSH):|
|very corrosive, pyrophoric in air, and reacts violently with acids|
|NFPA 704 (fire diamond)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|(what is ?)|
Potassium hydride, KH, is the inorganic compound of potassium and hydrogen. It is an alkali metal hydride. It is a white solid, although commercial samples appear gray. A powerful superbase that is useful in organic synthesis, it is also a dangerously reactive compound. For this reason it is sold commercially as a slurry (~35%) in mineral oil or sometimes paraffin wax to facilitate dispensing.
Potassium hydride is produced by direct combination of the metal and hydrogen:
This reaction was discovered by Humphry Davy soon after his 1807 discovery of potassium, when he noted that the metal would vaporize in a current of hydrogen when heated just below its boiling point.: p.25
KH reacts with water according to the reaction:
Potassium hydride is a superbase that is stronger than sodium hydride. It is extremely basic and it is used to deprotonate certain carbonyl compounds to give enolates. It also deprotonates amines to give the corresponding amides of the type KNHR and KNR2.
KH is pyrophoric in air, reacts violently with acids and ignites upon contact with oxidants and several other gasses. As a suspension in mineral oil, KH is less pyrophoric.