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Barium chloride

Barium chloride
CAS number 10361-37-2
Molecular formula BaCl2 (anhydrous)


Molar mass 208.2324 g/mol
Appearance White solid
Density 3.856 g/cm3, solid
Melting point

962 °C

Boiling point

1560 °C

Solubility in water 37.5 g/100 ml (26°C)
Crystal structure monoclinic or orthorhombic
Std enthalpy of
−858.56 kJ/mol
MSDS External MSDS
EU classification Toxic (T)
R-phrases R20, R25
S-phrases (S1/2), S45
Flash point Non-flammable
Related Compounds
Other anions Barium fluoride
Barium bromide
Barium iodide
Other cations Calcium chloride
Strontium chloride
Lead chloride
Supplementary data page
Structure and
n, εr, etc.
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Barium chloride is the chemical compound with the formula BaCl2. It is one of the most important water-soluble salts of barium. Like other barium salts, it is toxic and imparts a yellow-green coloration to a flame. It is also hygroscopic.

Additional recommended knowledge


Structure and properties

BaCl2 crystallizes in both the fluorite and lead chloride motifs, both of which accommodate the preference of the large Ba2+ ion for coordination numbers greater than six.[1] In aqueous solution BaCl2 behaves as a simple salt; In water it is a 1:2 electrolyte and the solution exhibits a neutral pH.

Barium chloride reacts with sulfate ion to produce a thick white precipitate of barium sulfate.

BaCl2(aq) + SO42- → BaSO4(s) + 2 Cl-(aq)

Oxalate effects a similar reaction:

BaCl2(aq) + Na2C2O4(aq) → BaC2O4 (s) + 2 NaCl(aq)


Although inexpensively available, barium chloride can be prepared from barium hydroxide or barium carbonate, the latter being found naturally as the mineral witherite. These basic salts react with hydrochloric acid to give hydrated barium chloride. On an industrial scale, it is prepared via a two step process from barite (barium sulfate)[4]:

BaSO4 + 4 C → BaS + 4 CO

This first step requires high temperatures.

BaS + CaCl2 → BaCl2 + CaS

The second step reqiures fusion of the reactants. The BaCl2 can then be leached out from the mixture with water.


As a cheap, soluble salt of barium, barium chloride finds wide application in the laboratory. It is commonly used as a test for sulfate ion (see chemical properties above). In industry, barium chloride is mainly used in the purification of brine solution in caustic chlorine plants and also in the manufacture of heat treatment salts, case hardening of steel, in the manufacture of pigments, and in the manufacture of other barium salts. BaCl2 is also used in fireworks to give a bright green color. However, its toxicity limits its applicability.


Barium chloride, along with other water-soluble barium salts, is toxic. Sodium sulfate is a potential antidote because it forms the insoluble solid BaSO4.


  1. ^ Wells, A.F. (1984) Structural Inorganic Chemistry, Oxford: Clarendon Press. ISBN 0-19-855370-6.
  1. Greenwood, N. N.; & Earnshaw, A. (1997). Chemistry of the Elements (2nd Edn.), Oxford: Butterworth-Heinemann. ISBN 0-7506-3365-4.
  2. Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
  3. The Merck Index, 7th edition, Merck & Co., Rahway, New Jersey, 1960.
  4. H. Nechamkin, The Chemistry of the Element, McGraw-Hill, New York, 1968.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Barium_chloride". A list of authors is available in Wikipedia.
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