Ca2H

Ca2H is not a widely recognized standard chemical formula in inorganic chemistry. In common practice, calcium hydride is referred to as CaH2, an ionic solid used as a reducing agent and, in some applications, as a hydrogen storage material. If Ca2H appears in literature, it is typically a typographical error for CaH2 or a reference to a calcium-containing hydride cluster studied in specialized contexts; there is no broadly accepted stable compound with the exact formula Ca2H.

Calcium hydride (CaH2) overview. CaH2 consists of calcium ions in the Ca2+ state and two hydride ions (H−) per formula unit, forming an ionic lattice. It is a solid at room temperature and is sensitive to moisture and air. The material is commonly used as a reducing agent in organic synthesis and as a source of hydrogen in various chemical applications. Its hydrogen content is about 4.75% by weight, making it relevant for hydrogen storage discussions under certain conditions. Preparation is typically achieved by direct reaction of calcium metal with hydrogen gas at elevated temperatures, though commercial methods may vary. Calcium hydride readily hydrolyzes in water to produce calcium hydroxide and hydrogen gas: CaH2 + 2 H2O → Ca(OH)2 + 2 H2.

Handling and safety. CaH2 is reactive toward water and releases hydrogen gas, which is flammable. It should be stored in a dry, tightly sealed container under inert atmosphere or dry air, away from moisture. Proper protective equipment and ventilation are required during handling.

Notes. In high-pressure and cluster chemistry, other calcium hydride species and stoichiometries have been reported, but these are distinct from CaH2 and do not constitute a stable, widely recognized compound with formula Ca2H.