Calcium hydride

Calcium hydride
Calcium hydride
Names
IUPAC name
Calcium hydride
Other names
Calcium(II) hydride
Calcium dihydride
Hydrolith
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.029.263 Edit this at Wikidata
EC Number
  • 232-189-2
UNII
  • InChI=1S/Ca.2H/q+2;2*-1 checkY
    Key: UUGAXJGDKREHIO-UHFFFAOYSA-N checkY
  • InChI=1/Ca.2H/q+2;2*-1
    Key: UUGAXJGDKREHIO-UHFFFAOYAG
  • [H-].[H-].[Ca+2]
Properties
CaH2
Molar mass 42.094 g/mol
Appearance gray powder (white when pure)
Density 1.70 g/cm3, solid
Melting point 816 °C (1,501 °F; 1,089 K)
reacts violently
Solubility reacts in alcohol
Structure
Orthorhombic, oP12
Pnma, No. 62
Thermochemistry
41.4 J/(mol·K)[1]
−181.5 kJ/mol
−142.5 kJ/mol
Hazards
GHS labelling:
GHS07: Exclamation markGHS05: CorrosiveWater-react. 1GHS09: Environmental hazard
Danger
H260
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
3
3
2
W
Related compounds
Other cations
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Calcium hydride is the chemical compound with the formula CaH2, an alkaline earth hydride. This grey powder (white if pure, which is rare) reacts vigorously with water, liberating hydrogen gas. CaH2 is thus used as a drying agent, i.e. a desiccant.[2]

CaH2 is a saline hydride, meaning that its structure is salt-like. The alkali metals and the alkaline earth metals heavier than beryllium all form saline hydrides. A well-known example is sodium hydride, which crystallizes in the NaCl motif. These species are insoluble in all solvents with which they do not react. CaH2 crystallizes in the PbCl2 (cotunnite) structure.[3]

  1. ^ Zumdahl, Steven S. (2009). Chemical Principles (6th ed.). Houghton Mifflin Company. p. A21. ISBN 978-0-618-94690-7.
  2. ^ Gawley, Robert E.; Davis, Arnold (2001). "Calcium Hydride". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rc005. ISBN 0471936235.
  3. ^ Wells, A. F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.