Calcium bromide

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Calcium bromide
Hydrophilite.GIF
Names
IUPAC name
Calcium bromide
Other names
Calcium dibromide
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.240
EC Number 232-164-6
RTECS number EV9328000
UNII
Properties
CaBr2
Molar mass 199.89 g/mol (anhydrous)
235.98 g/mol (dihydrate)
Appearance anhydrous is hygroscopic colorless crystals
sharp saline taste
Density 3.353 g/cm3
Melting point 730 °C (1,350 °F; 1,000 K)
Boiling point 1,935 °C (3,515 °F; 2,208 K) (anhydrous)
810 °C (dihydrate)
125 g/100 mL (0 °C)
143 g/100 ml (20 °C)
312 g/100 mL (100 °C)
Solubility in alcohol, acetone soluble
Acidity (pKa) 9
-73.8·10−6 cm3/mol
Structure
rhomboid
Thermochemistry
75 J/mol K
130 J/mol K
-647.9 kJ/mol
-656.1 kJ/mol
Hazards
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Lethal dose or concentration (LD, LC):
4100 mg/kg (rat, oral)
1580 mg/kg (mouse, subcutaneous)
Related compounds
Other anions
Calcium fluoride
Calcium chloride
Calcium iodide
Other cations
Beryllium bromide
Magnesium bromide
Strontium bromide
Barium bromide
Radium 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

Calcium bromide is the name for compounds with the chemical formula CaBr2(H2O)x. Individual compounds include the anhydrous material (x = 0), the hexahydrate (x = 6), and the rare dihydrate (x = 2). All are white powders that dissolve in water, and from these solutions crystallizes the hexahydrate. The hydrated form is mainly used in some drilling fluids.[1]

Synthesis, structure, and reactions[edit]

It is produced by the reaction of calcium oxide, calcium carbonate with hydrobromic acid or the reaction of calcium metal with elemental bromine.[1]

It adopts the rutile structure, featuring octahedral Ca centres bound to six bromide anions, which also bridge to other Ca centres.

When strongly heated in air, calcium bromide will react with oxygen to produce calcium oxide and bromine:

2 CaBr2 + O2 → 2 CaO + 2 Br2

In this reaction the oxygen oxidizes the bromide to bromine.

Uses[edit]

It is mainly used as dense aqueous solutions for drilling fluids.[1] It is also used in neuroses medication, freezing mixtures, food preservatives, photography and fire retardants.[2]

References[edit]

  1. ^ a b c Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders “Bromine Compounds” Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a04_405
  2. ^ "Chemical Land 21". Retrieved 25 December 2008. 

External links[edit]