Barium bromide

Barium bromide

Identifiers
CAS Number	10553-31-8 (anhydrous) N 7791-28-8 (dihydrate) N
3D model (Jmol)	Interactive image
ChemSpider	59728 Y
ECHA InfoCard	100.031.024
UNII	TI8NM689HW N
InChI InChI=1S/Ba.2BrH/h;2*1H/q+2;;/p-2 Y Key: NKQIMNKPSDEDMO-UHFFFAOYSA-L Y InChI=1/Ba.2BrH/h;2*1H/q+2;;/p-2 Key: NKQIMNKPSDEDMO-NUQVWONBAE
SMILES [Ba+2].[Br-].[Br-]
Properties
Chemical formula	BaBr2 (anhydrous) BaBr2·2H2O (dihydrate)
Molar mass	297.14 g/mol
Appearance	White solid
Density	4.78 g/cm3 (anhydrous) 3.58 g/cm3 (dihydrate)
Melting point	857 °C (1,575 °F; 1,130 K)
Boiling point	1,835 °C (3,335 °F; 2,108 K)
Solubility in water	92.2 g/100 mL (0°C)
Magnetic susceptibility (χ)	-92.0·10−6 cm3/mol
Structure
Crystal structure	orthorhombic, oP12
Space group	Pnma, No. 62
Thermochemistry
Std enthalpy of formation (ΔfHo298)	−181.1 kcal/mol
Hazards
EU classification (DSD)	Harmful (Xn)
R-phrases	R20, R22
S-phrases	S28
Related compounds
Other anions	Barium fluoride Barium chloride Barium iodide
Other cations	Beryllium bromide Magnesium bromide Calcium bromide Strontium bromide Radium bromide Lead 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

BaBr₂·2H₂O (dihydrate)

Barium bromide is the chemical compound with the formula BaBr₂. Like barium chloride, it dissolves well in water and is toxic in aqueous solution.

BaBr₂ crystallizes in a lead chloride motif, giving white orthorhombic crystals which are deliquescent. In aqueous solution BaBr₂ behaves as a simple salt.

Barium bromide reacts with the sulfate ion from sulfuric acid to produce a precipitate of barium sulfate.

Similar reactions occur with oxalic acid, hydrofluoric acid, and phosphoric acid.

Barium bromide can be prepared from barium sulfide or barium carbonate via reaction with hydrobromic acid to give hydrated barium bromide. This happens over a short period of time

Barium bromide can be crystallized out from the solution in its dihydrate form, BaBr₂·2H₂O, which gives the anhydrous form upon heating to 120 °C.

Barium bromide is a precursor to chemicals used in photography and to other bromides.
Historically, barium bromide was used to purify radium in a process of fractional crystallization devised by Marie Curie. Since radium precipitates preferentially in a solution of barium bromide, the ratio of radium to barium in the precipitate would be higher than the ratio in the solution.