| IUPAC name
| Other names
|Molar mass||112.911 g/mol|
|Appearance||Unstable yellowish solution|
|Solubility||Reacts with bases|
|Acidity (pKa)||3.43-6.25 (est.)|
Std enthalpy of
|Safety data sheet||None|
| Hydrobromic acid|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Bromous acid is the inorganic compound with the formula of HBrO2. It is an unstable compound, although salts of its conjugate base, bromites, have been isolated. In acidic solution, bromites decompose to bromine.
Bromous acid is unstable and will rapidly decompose in aq. solution to hypobromite and bromate.
- HBrO2 + H2O2 → HBrO + H2O + O2
- 2 MnO−
4 + BrO−
2 + OH− → 2 MnO2−
4 + BrO−
3 + H2O
Due to its instability, the compound is poorly characterized, thus any properties of the compound are derived from its dilute solution.
Bromous acid is unstable and thus it is not commercially available.
Addition of acid to bromite salts will produce bromous acid, which is unstable and will rapidly decompose.
- Br2 + AgNO3 + H2O → HBrO + AgBr + HNO3
- 2 AgNO3 + HBrO + Br2 + H2O → HBrO2 + 2 AgBr + 2 HNO3
- HBrO + HClO → HBrO2 + HCl
A redox reaction of hypobromous acid can form bromous acid as its product:
- HBrO + H2O − 2e− → HBrO2 + 2H+
The |disproportionation reaction of two equivalents hypobromous acid results in the formation of both bromous acid and hydrobromic acid:
- 2 HBrO → HBrO2 + HBr
- 2 HBrO3 + HBr → 3 HBrO2
- Make bromite salts
- Chemical demonstrations
- Belousov–Zhabotinsky reaction
Bromous acid is unstable and corrosive.
Cannot be stored due to its instability.
Thiosulfates, sulfites, metabisulfites can be used to neutralize the compound to bromide.
- Kshirsagar, Girish; Field, Richard J.; Journal of Physical Chemistry; vol. 92; nb. 25; (1988); p. 7074 - 7079
- Field, Richard J.; Foersterling, Horst-Dieter; Journal of Physical Chemistry; vol. 90; nb. 21; (1986); p. 5400 - 5407
- Ariese, Freek; Ungvarai-Nagy, Zsuzsanna; Journal of Physical Chemistry; vol. 90; nb. 1; (1986); p. 1 - 4
- Bray, W. C.; Davis, P. R.; Journal of the American Chemical Society; vol. 52; (1930); p. 1427
- Richards, A. H.; Journal of the Society of Chemical Industry, London; vol. 25; (1906); p. 4