Calcium hydride

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Calcium hydride
Calcium hydride CaH2 sample by Ormarion.jpg
CaH2 granules
Names
IUPAC name
Calcium hydride
Other names
Calcium(II) hydride
Calcium dihydride
Identifiers
Jmol-3D images Image
Properties
CaH2
Molar mass 42.094 g/mol
Appearance White (pure) or gray (impure) powder
Density 1.70 g/cm3
Melting point 816 °C (1,501 °F; 1,089 K)
Boiling point Decomposes
Reacts
Solubility Reacts with alcohols, carboxylic acids
Insoluble in common solvents
Vapor pressure ~0 mmHg
Thermochemistry
41.4 J·mol−1·K−1
−181.5 kJ·mol−1
Hazards
Safety data sheet ApolloScientific
Related compounds
Related compounds
Lithium hydride
Sodium hydride
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Calcium hydride is the chemical compound with the formula CaH2, widely used as a drying agent, especially in drying solvents.

Properties

Chemical

Calcium hydride reacts with water to release hydrogen gas:

CaH2 + H2O → Ca(OH)2 + H2

Physical

Calcium hydride is a grey or white solid powder, insoluble in all solvents. It reacts vigorously with water and alcohols. CaH2 has a density of 1.70 g/cm3.

Availability

CaH2 is sold by various chemical suppliers.

Preparation

Calcium hydride can be made by reacting dry hydrogen gas with calcium metal at temperatures between 300 to 400 °C.

Projects

  • Dry solvents
  • Readily hydrogen source

Handling

Safety

Calcium hydride reacts with water, releasing flammable hydrogen gas.

Storage

Calcium hydride is best stored in closed and airtight containers.

Disposal

A simple way of neutralizing calcium hydride is to add it slowly in a large volume of water, in a well ventilated area. A slower, but safer way is to expose calcium hydride to water vapors. Instead of water, long chain alcohols can also be used to neutralize this compound.

References

Relevant Sciencemadness threads