Calcium bromide
 | |
| Names | |
|---|---|
| IUPAC name
Calcium bromide | |
| Other names
Calcium dibromide | |
| Identifiers | |
7789-41-5 anhydrous  7774-34-7 hexahydrate 22208-73-7 dihydrate  | |
| 3D model (Jmol) | Interactive image |
| ChEBI | CHEBI:31338 |
| ChemSpider | 23010 |
| ECHA InfoCard | 100.029.240 |
| EC Number | 232-164-6 |
| PubChem | 24608 |
| RTECS number | EV9328000 |
| UNII | 87CNY2EEBH |
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| 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 |
| Structure | |
| rhomboid | |
| Thermochemistry | |
| 75 J/mol K | |
| Std molar entropy (S |
130 J/mol K |
| Std enthalpy of formation (ΔfH |
-647.9 kJ/mol |
| Gibbs free energy (ΔfG˚) |
-656.1 kJ/mol |
| Hazards | |
| NFPA 704 | |
| 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). | |
| verify (what is ?) | |
| 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
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 produce a substance having calcium oxide and bromine:
- 2 CaBr2 + O2 → 2 CaO + 2 Br2
In this reaction the oxygen oxidizes the bromide to bromine.
Uses
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
- 1 2 3 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
- ↑ "Chemical Land 21". Retrieved 25 December 2008.