A hydride is a chemical compound in which hydrogen (H) acts as an anion, meaning it carries a negative charge (H⁻). This contrasts with most hydrogen compounds where hydrogen exists as a cation (H⁺). Hydrides are typically formed when hydrogen combines with a more electropositive element, particularly alkali metals (Group 1) and alkaline earth metals (Group 2) in the periodic table, but can also be formed with transition metals and nonmetals. The properties of hydrides vary widely depending on the element to which hydrogen is bonded, ranging from salt-like ionic hydrides to more covalent, volatile hydrides.
Hydride meaning with examples
- Lithium hydride (LiH), a classic example, reacts vigorously with water, producing hydrogen gas and lithium hydroxide. It's a powerful reducing agent, used in organic synthesis. The strong ionic bond between Li+ and H- gives it high thermal stability, making it valuable in various applications. Its role in reducing complex molecules highlights its reactivity.
- Sodium borohydride (NaBH₄) is widely used in organic chemistry to reduce carbonyl groups. It's a milder reducing agent compared to lithium aluminum hydride. Unlike the latter, it can be safely used with water and alcohols making it versatile, safe, and user-friendly in a wide variety of organic reactions and applications.
- Metal hydrides, such as palladium hydride, can absorb large amounts of hydrogen, acting as a hydrogen storage medium. This property is crucial in fuel cell research and development. The ability to reversibly store hydrogen in a compact form offers promise for hydrogen-powered transportation and energy sustainability.
- Silane (SiH₄), a covalent hydride, is a colorless, pyrophoric gas used in semiconductor manufacturing for silicon deposition. It is a precursor in the fabrication of microchips and other electronic components, with strict safety precautions due to its flammability when in contact with air.
- Calcium hydride (CaH₂) reacts with water to generate hydrogen gas, making it a convenient desiccant and hydrogen source in laboratory settings. Its reaction with water makes it useful in creating hydrogen gas for specialized purposes, especially in remote areas or when on an exploration expedition.