Calcium bromide is the name for compounds with the chemical formula Ca Br₂(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.

Synthesis, structure, and reactions

It is produced by the reaction of Cao,

calcium oxide Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term "''lime''" connotes calcium-containing inorganic ...

, calcium carbonate with

hydrobromic acid Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide (HBr) in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at and contains 47.6% HBr by mass, which is 8.77 mol/L. ...

or the reaction of

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

metal with elemental

bromine Bromine is a chemical element with the symbol Br and atomic number 35. It is the third-lightest element in group 17 of the periodic table ( halogens) and is a volatile red-brown liquid at room temperature that evaporates readily to form a simi ...

.Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders “Bromine Compounds” Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. It adopts the

rutile Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest refractive indices at visib ...

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

and

: :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. It is also used in neuroses medication, freezing mixtures, food preservatives, photography and fire retardants. Calcium bromide has been shown to undergo

complexation A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

with

triphenylphosphine oxide Triphenylphosphine oxide (often abbreviated TPPO) is the organophosphorus compound with the formula OP(C6H5)3, also written as Ph3PO or PPh3O (Ph = C6H5). This colourless crystalline compound is a common but potentially useful waste product in ...

, allowing for removal of triphenylphosphine oxide from reaction mixtures without the use of chromatography.

References

External links

Calcium bromide at WebElements

MSDS
{{DEFAULTSORT:Calcium Bromide Calcium compounds Bromides Alkaline earth metal halides