Hydrobromic acid
General
Molecular formula	HBr
Molar mass	80.91 g/mol
Appearance	colorless liquid
CAS number	*
Properties
Density and phase	variable
Solubility in water	aqueous solution
Melting point	variable
Boiling point	variable
Acidity (pKa)	−9
Hazards
MSDS	External MSDS
EU classification	Corrosive (C)
NFPA 704
R-phrases	,
S-phrases	, , ,
Flash point	non flammable
RTECS number	MW3850000
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	Hydrofluoric acid Hydrochloric acid Hydroiodic acid
Related compounds	Hydrogen bromide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Chemical infobox

Hydrobromic Acid is formed by dissolving the diatomic molecule hydrogen bromide in water. It has a pK_a of −9, making it a stronger acid than hydrochloric acid, but not as strong as hydroiodic acid. Hydrobromic acid is one of the strongest mineral acids known. (See strong acid.)

Uses

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Hydrobromic acid is mainly used for the production of inorganic bromides, cleaving alkoxy and phenoxy compounds, substitution of hydroxyl groups, and the hydrobromination of alkenes. It also catalyzes alkylation reactions and the extraction of certain ores.¹

Syntheses

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Hydrobromic acid can be prepared in the laboratory via the reaction of Br₂, SO₂, and water.2 More typically laboratory preparations involve the production of anhydrous HBr, which is then dissolved in water.

Hydrobromic acid has commonly been prepared industrially by reacting bromine with either sulfur or phosphorus and water. However, it can also be produced electrolytically.²

Hydrobromic acid is available in various concentrations and purities.

References

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(1) Carlin, W. W. U.S. Patent 4,147,601, April 3, 1979.

(2) Scott, A. (1900) Preparation of pure hydrobromic acid. J. Chem. Soc. Trans., 648-650.

External links

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• International Chemical Safety Card 0282
• NIOSH Pocket Guide to Chemical Hazards

Acids | Bromides | Nonmetal halides

Bromwasserstoff | Acido bromidrico | Waterstofbromide | Bromowodór | Бромоводород | Bromovodikova kislina