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hydronium
Sign in to saveAlso known as hydroxonium, H3O(+), [OH3](+), hydronium cation, hydronium ion, oxonium, hydrogen, proton
In chemistry, hydronium (hydroxonium in traditional British English) is the cation , also written as , the type of oxonium ion produced by protonation of water. It is often viewed as the positive ion present when an Arrhenius acid is dissolved in water, as Arrhenius acid molecules in solution give up a proton (a positive hydrogen ion, ) to the surrounding water molecules (). In fact, acids must be surrounded by more than a single water molecule in order to ionize, yielding aqueous and conjugate base.
Chemical data
- Formula
- H3O+
- Molecular weight
- 19.023 g/mol
- IUPAC name
- hydron;hydrate
- SMILES
- [H+].O
- InChIKey
- XLYOFNOQVPJJNP-UHFFFAOYSA-O
- Polar surface area
- 1 Ų
- H-bond donors
- 2
- H-bond acceptors
- 1
- Formal charge
- 1
via PubChem
Wikidata facts
- Mass
- 19.01839
Show 4 more facts
- Commons category
- Hydronium ion
- canonical SMILES
- [OH3+]
- pKa
- 0.00
- chemical formula
- H₃O⁺
via Wikidata · CC0
~15 min read
Article
12 sectionsContents
- Relation to pH
- Nomenclature
- Structure
- Acids and acidity
- Solvation
- Solid hydronium salts
- Interstellar H<sub>3</sub>O<sup>+</sup>
- Interstellar chemistry
- Astronomical detections
- See also
- References
- External links
In chemistry, hydronium (hydroxonium in traditional British English) is the cation , also written as , the type of oxonium ion produced by protonation of water. It is often viewed as the positive ion present when an Arrhenius acid is dissolved in water, as Arrhenius acid molecules in solution give up a proton (a positive hydrogen ion, ) to the surrounding water molecules (). In fact, acids must be surrounded by more than a single water molecule in order to ionize, yielding aqueous and conjugate base.
Three main structures for the aqueous proton have garnered experimental support: the Eigen cation, which is a tetrahydrate, H3O+(H2O)3 the Zundel cation, which is a symmetric dihydrate, H+(H2O)2 and the Stoyanov cation, an expanded Zundel cation, which is a hexahydrate: H+(H2O)2(H2O)4