Barium bromide

Barium bromide is the chemical compound with the formula BaBr2. Like barium chloride, it dissolves well in water and is toxic.

Barium bromide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.024
EC Number
  • 234-140-0
UNII
Properties
BaBr2 (anhydrous)

BaBr2·2H2O (dihydrate)

Molar mass 297.14 g/mol
Appearance White solid
Density 4.78 g/cm3 (anhydrous)
3.58 g/cm3 (dihydrate)
Melting point 857 °C (1,575 °F; 1,130 K)
Boiling point 1,835 °C (3,335 °F; 2,108 K)
92.2 g/100 mL (0°C)
-92.0·10−6 cm3/mol
Structure
orthorhombic, oP12
Pnma, No. 62
Thermochemistry
−181.1 kcal/mol
Hazards
Main hazards Toxic
Safety data sheet NIH BaBr
GHS pictograms
GHS Signal word Warning
H302, H332
P261, P264, P270, P271, P301+312, P304+312, P304+340, P312, P330, P501
NFPA 704 (fire diamond)
Flammability code 0: Will not burn. E.g. waterHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
0
3
0
Related compounds
Other anions
 Barium fluoride
Barium chloride
Barium iodide
Other cations
 Beryllium bromide
Magnesium bromide
Calcium bromide
Strontium bromide
Radium bromide
Lead bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Structure and properties

BaBr2 crystallizes in a lead chloride motif, giving white orthorhombic crystals that are deliquescent.[1] In aqueous solution BaBr2 behaves as a simple salt.

Solutions of barium bromide reacts with the sulfate salts to produce a solid precipitate of barium sulfate.

BaBr2 + SO42− → BaSO4 + 2 Br−

Similar reactions occur with oxalic acid, hydrofluoric acid, and phosphoric acid, giving solid precipitates of barium oxalate, fluoride, and phosphate, respectively.

Preparation

Barium bromide can be prepared by treating barium sulfide or barium carbonate with hydrobromic acid:

BaS + 2 HBr → BaBr2 + H2S
BaCO3 + 2 HBr → BaBr2 + CO2 + H2O

Barium bromide crystallizes from concentrated aqueous solution in its dihydrate , BaBr2·2H2O. Heating this dihydrate to 120 °C gives the anhydrous salt. [2]

Uses

Barium bromide is a precursor to chemicals used in photography and to other bromides.
Historically, barium bromide was used to purify radium in a process of fractional crystallization devised by Marie Curie. Since radium precipitates preferentially in a solution of barium bromide, the ratio of radium to barium in the precipitate would be higher than the ratio in the solution.[3]

Safety

Barium bromide, along with other water-soluble barium salts, is toxic.

References
  1. Brackett, Elizabeth B.; Breackett, Thomas E.; Sass, Ronald L. (December), "The Crystal Structures of Barium Chloride, Barium Bromide, and Barium Iodide.", The Journal of Physical Chemistry (– Scholar search), 67 (published 1963), p. 2132, retrieved 2007-12-03 Check date values in: |date= (help)
  2. Patnaik, Pradyot (2003), Handbook of Inorganic Chemical Compounds, McGraw-Hill Professional, pp. 81–82, ISBN 978-0-07-049439-8, retrieved 2007-12-03
  3. Sime, Ruth Lewin (1996), Lise Meitner: A Life in Physics, University of California Press, p. 233, ISBN 978-0-520-20860-5, retrieved 2007-12-03
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