Calcium bromide

Calcium bromide

Names
IUPAC name Calcium bromide
Other names Calcium dibromide
Identifiers
CAS Number	7789-41-5 anhydrous Y 7774-34-7 hexahydrate N 22208-73-7 dihydrate N
3D model (Jmol)	Interactive image
ChEBI	CHEBI:31338 Y
ChemSpider	23010 Y
ECHA InfoCard	100.029.240
EC Number	232-164-6
PubChem	24608
RTECS number	EV9328000
UNII	87CNY2EEBH Y
InChI InChI=1S/2BrH.Ca/h2*1H;/q;;+2/p-2 Y Key: WGEFECGEFUFIQW-UHFFFAOYSA-L Y InChI=1/2BrH.Ca/h2*1H;/q;;+2/p-2 Key: WGEFECGEFUFIQW-NUQVWONBAA
SMILES [Ca+2].[Br-].[Br-]
Properties
Chemical formula	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)
Solubility in water	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
Magnetic susceptibility (χ)	-73.8·10−6 cm3/mol
Structure
Crystal structure	rhomboid
Thermochemistry
Specific heat capacity (C)	75 J/mol K
Std molar entropy (So298)	130 J/mol K
Std enthalpy of formation (ΔfHo298)	-647.9 kJ/mol
Gibbs free energy (ΔfG˚)	-656.1 kJ/mol
Hazards
NFPA 704	0 2 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	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).
N  (what is YN ?)
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.

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

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:

In this reaction the oxygen oxidizes the bromide to bromine.

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