Potassium hydride
 |
|
| Identifiers | |
|---|---|
7693-26-7 
|
|
| 3D model (Jmol) | Interactive image |
| ChemSpider |
74121
|
| ECHA InfoCard | 100.028.823 |
| EC Number | 232-151-5 |
| PubChem | 82127 |
|
|
|
|
| Properties | |
| KH | |
| Molar mass | 40.1062 g/mol |
| Appearance | colourless crystals |
| Density | 1.43 g/cm3 |
| Melting point | decomposes at ~400 °C |
| reacts | |
| Solubility | insoluble in benzene, diethyl ether, CS2 |
| Structure | |
| cubic, cF8 | |
| Fm3m, No. 225 | |
| Thermochemistry | |
| 37.91 J/(mol K) | |
|
Std enthalpy of
formation (ΔfH |
-57.82 kJ/mol |
| Related compounds | |
|
Other cations
|
Lithium hydride Sodium hydride Rubidium hydride Caesium hydride |
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
|
 (what is  ?) |
|
| Infobox references | |
Potassium hydride, KH, is the inorganic compound of potassium and hydride, and is therefore classed as an alkali metal hydride. It is a white solid, although commercial samples appear gray. A powerful base 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.
Potassium hydride is soluble in fused hydroxides (such as molten sodium hydroxide) and salt mixtures, but not in organic solvents.
KH reacts with water according to the reaction:
Potassium hydride is a superbase that is stronger than sodium hydride. It is used to deprotonate certain carbonyl compounds to give enolates. It also deprotonated 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, including oxygen and other gases.
...
Wikipedia