Barium chloride

Barium chloride
General
Molecular formula	BaCl₂
Molar mass	208.232 g/mol
Appearance	White solid
CAS number	10361-37-2
Properties
Density and phase	3.856 g/cm³, solid
Solubility in water	37.5 g/100 ml (26°C)
Solubility in methanol	1.7 g/100g
Solubility in ethanol	Slightly soluble
Melting point	962°C
Boiling point	1560°C
Magnetic Susceptibility	-7.26e-005 cm³/mol
Structure
Coordination geometry	?
Crystal structure	monoclinic or orthorhombic
Thermodynamic data
Std enthalpy of formation Δ_fH^o₂₉₈	−858.56 kJ/mol
Standard molar entropy S^o₂₉₈	123.70 J·K⁻¹·mol⁻¹
Heat of Fusion	76.1 J/g
Hazards
MSDS	External MSDS
EU classification	Toxic (T)
R-phrases	,
S-phrases	,
Flash point	Non-flammable
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	Barium fluoride Barium bromide Barium iodide
Other cations	Calcium chloride Strontium chloride
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Chemical infobox

Barium chloride (BaCl₂) is a salt of barium and chlorine. It is ionic and water-soluble. It is toxic like other barium salts. It imparts a yellow-green coloration to a flame.

Chemical properties

Since barium chloride is soluble in water, it can react with sulfate ion to produce a thick white precipitate of barium sulfate. It is also hygroscopic.

BaCl₂(aq) + SO₄^2-(aq) → BaSO₄(s) + 2 Cl^-(aq)

Barium chloride behaves as a simple salt, and it is completely neutral in solution.

Preparation

Barium chloride may be prepared from barium hydroxide or barium carbonate (found naturally as witherite) reacting with hydrochloric acid. On an industrial scale, it can be prepared via a two step process from barite (barium sulfate)^{^*}:

BaSO₄ + 4 C → BaS + 4 CO (done with heat)

BaS + CaCl₂ → BaCl₂ + CaS (done by fusion of the mixture)

The BaCl₂ can then be leached out from the mixture with water.

Uses

As a cheap, soluble salt of barium, barium chloride finds wide application in the laboratory. Most commonly it is used as a test for sulfate ion (see chemical properties above). It can be used to prepare other insoluble salts such as the oxalate by precipitation:

BaCl₂(aq) + Na₂C₂O₄(aq) → Ba₂C₂O₄ (s) + 2 NaCl(aq)

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 colour. However, its toxicity limits its applicability.

Precautions

Highly toxic- 0.8-0.9g is fatal.

References

N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, Oxford, UK, 1984.
Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
The Merck Index, 7th edition, Merck & Co., Rahway, New Jersey, 1960.
H. Nechamkin, The Chemistry of the Element, McGraw-Hill, New York, 1968.

External links

International Chemical Safety Card 0614. (anhydrous)
International Chemical Safety Card 0615. (dihydrate)
NIOSH Pocket Guide to Chemical Hazards.
European Chemicals Bureau.
Barium chloride's use in industry.