Hydride Ion — Definition, Formula, Properties & Uses | AllChemicals | AllChemicals

Q: What is the formula for Hydride Ion?

The formula or notation for Hydride Ion is: Hydride ion: H⁻; isoelectronic with He; formed by reduction of H⁺

Formula / Notation	Hydride ion: H⁻; isoelectronic with He; formed by reduction of H⁺
Also Known As	H⁻, hydridic hydrogen, ionic hydride anion

What is Hydride Ion?

The hydrogen anion H⁻, consisting of a proton and two electrons. Hydride ions are powerful reducing agents and strong bases. Metal hydrides like NaH and LiAlH₄ are important reducing agents in organic synthesis, used to reduce carbonyl compounds to alcohols.

Formula & Notation

Hydride ion: H⁻; isoelectronic with He; formed by reduction of H⁺

Other Names / Synonyms: H⁻, hydridic hydrogen, ionic hydride anion

Properties & Characteristics

The hydride ion (H⁻) is a hydrogen atom with an extra electron, giving a charge of −1. It is the anion found in ionic hydrides (NaH, LiH, CaH₂). H⁻ is a strong Lewis base and Brønsted base, and a strong reducing agent: H⁻ + H₂O → H₂ + OH⁻. The H⁻ ion is also the hydridic hydrogen in metal hydride reducing agents (LiAlH₄, NaBH₄), where it acts as a nucleophilic hydride donor to electrophilic carbonyl carbons.

Uses & Applications

Hydride ions (as delivered by LiAlH₄, NaBH₄, DIBAL-H) are essential reducing agents in organic synthesis. Metal hydrides are used as hydrogen storage media for portable hydrogen energy. In inorganic chemistry, ionic hydrides react with protic reagents to generate H₂ gas.

Safety Information

Ionic hydrides react violently with water and moisture to generate H₂ gas and strong base (NaOH, LiOH). H₂ is flammable and the exothermic reaction can ignite it. Ionic hydride fires cannot be extinguished with water — use dry sand, dry graphite, or dry NaCl.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Hydride Ion

Formula Hydride ion: H⁻; isoelectronic with He; formed by reduction of H⁺

Index All "H" terms

Synonyms H⁻, hydridic hydrogen, ionic hydride anion

Frequently Asked Questions

What is Hydride Ion?

The hydrogen anion H⁻, consisting of a proton and two electrons. Hydride ions are powerful reducing agents and strong bases. Metal hydrides like NaH and LiAlH₄ are important reducing agents in organic synthesis, used to reduce carbonyl compounds to alcohols.

What is Hydride Ion used for?

Is Hydride Ion hazardous?

What is the formula for Hydride Ion?

More "H" Terms

Haber Process N₂ + 3H₂ ⇌ 2NH₃ | ΔH = −92 kJ/mol Hafnium Hf Half Cell Half Life Half-Cell E = E° − (RT/nF)lnQ Half-Life A(t) = A₀e^(−λt); t½ = ln2/λ Half-Reaction Halide X⁻ (e.g., F⁻, Cl⁻, Br⁻, I⁻) Halogen F₂, Cl₂, Br₂, I₂, At; Group 17; ns²np⁵ valence configuration Halogenation C-X + Cl₂/Br₂ (hv or AlCl₃) → C-X(halogen); EAS or radical pathway Halogens Hard Acid Hard acid: small, highly charged, low polarisability (e.g., H⁺, Mg²⁺, Al³⁺)

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