What is "calcium hydride"

n. a salt-like binary compound (CaH2) used as a reducing agent and source of hydrogen [syn: hydrolith]

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

CaH is a saline hydride, meaning that its structure is salt-like. The alkali metals and the alkaline earth metals 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. CaH crystallizes in the PbCl ( cotunnite) structure.