Calcium bromide
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IUPAC name Calcium bromide | |
Other names Calcium dibromide | |
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ChEBI |
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ECHA InfoCard | 100.029.240 |
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InChI
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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 | 1,815 °C (3,299 °F; 2,088 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 |
-73.8·10−6 cm3/mol | |
Structure | |
rhomboid | |
Thermochemistry | |
Heat capacity (C) | 75 J/mol K |
Std molar entropy (S⦵298) | 130 J/mol K |
Std enthalpy of formation (ΔfH⦵298) | -647.9 kJ/mol |
Gibbs free energy (ΔfG⦵) | -656.1 kJ/mol |
Hazards | |
NFPA 704 (fire diamond) | 1 0 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 verify (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.[1]
Synthesis, structure, and reactions
It is produced by the reaction of calcium oxide, calcium carbonate with bromine in the presence of a reducing agent such as formic acid or formaldehyde:[1]
- CaO + Br2 + HCO2H → CaBr2 + H2O + CO2
Solid calcium bromide adopts the rutile structure, featuring octahedral Ca2+ centres bound to six bromide anions, which also bridge to other Ca2+ centres.
When strongly heated in air, calcium bromide reacts with oxygen to produce calcium oxide and bromine:
- 2 CaBr2 + O2 → 2 CaO + 2 Br2
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]
It minimizes the emission of gaseous mercury in the combustion of coal.[1]
In the laboratory
Calcium bromide forms complexes with triphenylphosphine oxide, allowing for removal of triphenylphosphine oxide from reaction mixtures without the use of chromatography.[3]
References
- ^ a b c d Yoffe, David; Frim, Ron; Ukeles, Shmuel D.; Dagani, Michael J.; Barda, Henry J.; Benya, Theodore J.; Sanders, David C. (2013). "Bromine Compounds". Ullmann's Encyclopedia of Industrial Chemistry. pp. 1–31. doi:10.1002/14356007.a04_405.pub2. ISBN 978-3-527-30385-4.
- ^ "Chemical Land 21". Retrieved 25 December 2008.
- ^ Rodríguez Hergueta, Antonio (2022). "Easy Removal of Triphenylphosphine Oxide from Reaction Mixtures by Precipitation with CaBr2". Organic Process Research & Development. 26 (6): 1845–1853. doi:10.1021/acs.oprd.2c00104. S2CID 249558328.
External links
- Calcium bromide at WebElements
- MSDS
- v
- t
- e
- CaH2
- CaF2
- CaCl2
- Ca(ClO)2
- Ca(ClO3)2
- Ca(ClO4)2
- CaBr2
- Ca(BrO3)2
- CaI2
- Ca(IO3)2
- CaICl
- CaC2
- Ca(CN)2
- CaCN2
- CaCO3
- Ca(HCO3)2
- CaSi
- CaSi2
- Ca2SiO4
- Ca3(BO3)2
- CaAl2O4
- Ca3Al2O6
- Ca(MnO4)2
- CaCrO4
- CaTiO3
- CaC2O4
- Ca(HCO2)2
- Ca(CH3CO2)2
- Ca(C3H5O2)2
- CaC4H2O4
- Ca3(C6H5O7)2
- C3H7CaO6P
- Ca(C6H5O5S)2
- Ca(C6H7O6)2
- C10H11CaN4O8P
- CaC10H12O4N5PO4
- C10H16CaN2O8
- C12H22CaO14
- C14H26CaO16
- C18H32CaO19
- C36H70CaO4
- C24H40B2CaO24