- Formula: HBr
- Hill system formula: Br1H1
- CAS registry number: [10035-10-6]
- Formula weight: 80.912
- Class: bromide
- Colour: colourless
- Appearance: gas
- Melting point: -88.6°C
- Boiling point: -67°C
- Density: 2603 kg m-3 (liquid near freezing point); 3.55 kg m-3 (gas)
The following are some synonyms of hydrogen bromide:
- hydrogen bromide
- hydrogen(I) bromide
- hyrobromic acid
The oxidation number of hydrogen in hydrogen bromide is 1.
Hydrogen bromide gas can be made in the laboratory by the bromination of tetralin (1,2,3,4-tetrahydronapthalene). The downside is that half of the bromine is lost. The yield is about 94% (that is, 47% of the bromine ends up as HBr).
C10H12 + 4Br2 → C10H8Br4 + 4HBr
Hydrogen bromide gas may also be made in the laboratory by the reaction of concentrated sulphuric acid upon sodium bromide. However, a lot of the product is lost by oxidation with excess sulphuric acid to form bromine and sulphur dioxide.
NaBr(s) + H2SO4 → HBr(g) + NaHSO4(s)
Hydrogen bromide may be made in the laboratory by the reaction between purified hydrogen gas and bromine. This is catalyzed by platinized asbestos and carried out in a quartz tube at 250°C.
Br2 + H2 [Pt] → 2HBr
Solid state structure
- Geometry of hydrogen: 1 coordinate: terminus
- Prototypical structure:
The table shows element percentages for HBr (hydrogen bromide).
Isotope pattern for HBr
The chart below shows the calculated isotope pattern for the formula HBr with the most intense ion set to 100%.
The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.
- R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
- N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
- F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
- A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
- R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
- A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
- A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
- J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
- D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
- J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
- J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.