Definition

1. Noun:
   • A chemical compound: A hydride is any binary compound formed by the union of hydrogen with another, more electropositive element or group.

Usage

• Hydrides are a class of chemical compounds. The term is used primarily in chemistry to categorize and discuss compounds where hydrogen acts as the anion (H⁻) or is bonded in a similar manner.
• The general formula is often represented as , where is the other element.
• Example: "Sodium hydride (NaH) is a common example of a saline hydride."

Examples

• Noun:
  • Lithium aluminum hydride is a powerful reducing agent used in organic synthesis.
  • The properties of a metal hydride, like palladium hydride, are of interest for hydrogen storage.
  • Ammonia (NH₃) is not typically classified as a hydride, though it contains hydrogen.

Advanced Usage

• "Complex hydride": Refers to hydrides containing complex anions, such as borohydrides (e.g., sodium borohydride, NaBH₄) or alanates.
  • Complex hydrides are being researched for solid-state hydrogen storage applications.
• "Binary hydride": Emphasizes the compound consists of only two elements: hydrogen and one other.
  • Water (H₂O) is a binary compound of hydrogen and oxygen but is not considered a hydride in standard chemical nomenclature.

Variants and Related Words

• Hydridic (adj): Pertaining to or characteristic of a hydride, especially describing the H⁻ ion.
  • The hydridic hydrogen in sodium hydride is highly reactive.
• Hydride ion: The H⁻ anion itself.
  • The hydride ion is a strong base and a powerful reducing agent.

Synonyms

• Hydrogen compound: A broader, less specific term for any compound containing hydrogen.
• Binary hydrogen compound: A more descriptive synonym that specifies the two-element nature.

Related Phrases / Terminology

• Form a hydride: To combine chemically to create a hydride compound.
  • Some metals can form hydrides when exposed to hydrogen gas under pressure.
• Hydride formation: The process or reaction by which a hydride is produced.
  • The enthalpy of hydride formation is a key thermodynamic parameter.

Notes on Meaning

• In standard inorganic chemistry, "hydride" specifically implies hydrogen in a formal negative oxidation state. This distinguishes it from most common hydrogen compounds like water (H₂O) or hydrochloric acid (HCl), where hydrogen has a positive oxidation state.
• The classification of hydrides often includes:
  • Ionic (saline) hydrides (e.g., NaH, CaH₂)
  • Covalent hydrides (e.g., BH₃, CH₄)
  • Metallic (interstitial) hydrides (e.g., PdHₓ, TiH₂)

Noun

1. any binary compound formed by the union of hydrogen and other elements