What Is Calcium Hydride?
Calcium hydride, with the formula H2Ca, is primarily a gray powder, though it can appear as white crystals when pure. It is designated for research and development uses only, excluding pharmaceutical, household, or other applications.
Produced by reacting calcium with hydrogen at temperatures between 300°C to 400°C in the presence of hydrogen and sodium chloride, or through the reaction of calcium chloride with hydrogen and sodium metal, calcium hydride is a versatile compound.
Uses of Calcium Hydride
1. Desiccant
As a relatively mild desiccant, calcium hydride is preferred for handling safety over more reactive alternatives. It’s utilized for drying basic solvents and as a preparatory drying step before employing more potent desiccants.
2. Hydrogen Production
Traditionally, calcium hydride has been a source of hydrogen for both industrial and experimental applications, including safe methods to inflate balloons and determine the water content in diesel fuel through the hydrogen produced.
3. Reducing Agent
Effective in reducing various metals into their powder forms at temperatures between 600 and 1,000 °C, calcium hydride serves as a powerful reducing agent.
Properties of Calcium Hydride
1. Physical Properties
With a molecular weight of 42.09 g/mol and a CAS number of 7789-78-8, calcium hydride is an odorless light gray powder. It has a melting point of 816°C and decomposes at temperatures above 600°C, exhibiting a non-flammable nature under normal conditions but posing a dust explosion risk when finely dispersed.
2. Chemical Properties
While chemically stable under normal atmospheric conditions, calcium hydride reacts violently with water, alcohols, halogens, and certain acids, potentially leading to combustion or explosion.
Other Information on Calcium Hydride
1. Safety
Calcium hydride requires careful handling to avoid violent reactions with water and air moisture. It’s an irritant to the skin and eyes and necessitates careful disposal and handling.
2. First Aid Measures
For skin or eye contact, immediate rinsing with water is advised. In cases of inhalation, move to fresh air, and if ingested, drink water and seek medical attention promptly, providing SDS information to the physician.
3. Handling Instructions
Handling should involve protective gear and measures to prevent dust generation, with operations ideally conducted under inert gas to avoid moisture contact. Contaminated clothing should be changed, and thorough washing is recommended post-handling.
4. Storage
Store in a dry, tightly sealed container away from heat and ignition sources, ensuring no contact with water to prevent the release of flammable gases.