Barium chloride

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Barium chloride
Names
Other names
  • Barium dichloride
  • Barium muriate
  • Muryate of Barytes[1]
  • Neutral barium chloride
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
 100.030.704 Edit this at Wikidata
EC Number
  • 233-788-1
RTECS number
  • CQ8750000 (anhydrous)
    CQ8751000 (dihydrate)
UNII
UN number 1564
  • InChI=1S/Ba.2ClH/h;2*1H/q+2;;/p-2 checkY
    Key: WDIHJSXYQDMJHN-UHFFFAOYSA-L checkY
  • InChI=1/Ba.2ClH/h;2*1H/q+2;;/p-2
    Key: WDIHJSXYQDMJHN-NUQVWONBAL
  • [Ba+2].[Cl-].[Cl-]
Properties
BaCl2
Molar mass 208.23 g/mol (anhydrous)
244.26 g/mol (dihydrate)
Appearance White powder, or colourless or white crystals (anhydrous)
Colourless rhomboidal crystals (dihydrate)[2][3]
Odor Odourless
Density 3.856 g/cm3 (anhydrous)
3.0979 g/cm3 (dihydrate)
Melting point 962 °C (1,764 °F; 1,235 K) (960 °C, dihydrate)
Boiling point 1,560 °C (2,840 °F; 1,830 K)
  • 31.2 g/(100 mL) (0 °C)
  • 35.8 g/(100 mL) (20 °C)
  • 59.4 g/(100 mL) (100 °C)
Solubility Soluble in methanol, insoluble ethyl acetate, slightly soluble in hydrochloric acid and nitric acid, very slightly soluble in ethanol.[4][3] The dihydrate of barium chloride is soluble in methanol, almost insoluble in ethanol, acetone and ethyl acetate.[3]
−72.6·10−6 cm3/mol
Structure
monoclinic
(dihydrate)
polymorph)
  • 10 (the post-cotunnite polymorph at pressures of 7–10 GPa)
    • Thermochemistry
    123.9 J/(mol·K)
    Std enthalpy of
    formation
    (ΔfH⦵298)
    		 −858.56 kJ/mol
    Hazards
    Occupational safety and health (OHS/OSH):
    Main hazards
    		 Highly toxic, corrosive
    GHS labelling:
    GHS06: Toxic
    Danger
    H301, H302, H332
    P261, P264, P270, P271, P301+P310, P304+P312, P304+P340, P312, P321, P330, P405, P501
    NFPA 704 (fire diamond)
    NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
    3
    0
    0
    Flash point Non-flammable
    Lethal dose or concentration (LD, LC):
    78 mg/kg (rat, oral)
    50 mg/kg (guinea pig, oral)[6]
    112 mg/kg (as Ba) (rabbit, oral)
    59 mg/kg (as Ba) (dog, oral)
    46 mg/kg (as Ba) (mouse, oral)[6]
    NIOSH (US health exposure limits):
    PEL (Permissible)
    		 TWA 0.5 mg/m3[5]
    REL (Recommended)
    		 TWA 0.5 mg/m3[5]
    IDLH
    (Immediate danger)
    		 50 mg/m3[5]
    Safety data sheet (SDS) NIH BaCl
    Related compounds
    Other anions
    Other cations
    Supplementary data page
    Barium chloride (data page)
    Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
    ☒N verify (what is checkY☒N ?)

    Barium chloride is an

    hygroscopic, converting to the dihydrate BaCl2·2H2O, which are colourless crystals with a bitter salty taste. It has limited use in the laboratory and industry.[7][3]

    Preparation

    On an industrial scale, barium chloride is prepared via a two step process from

    barite (barium sulfate).[8]
    The first step requires high temperatures.

    BaSO4 + 4 C → BaS + 4 CO

    The second step requires reaction between barium sulfide and hydrogen chloride:

    BaS + 2 HCl → BaCl2 + H2S

    or between barium sulfide and calcium chloride:

    BaS + CaCl2 → CaS + BaCl2[2]

    In place of HCl, chlorine can be used.[7] Barium chloride is extracted out from the mixture with water. From water solutions of barium chloride, its dihydrate (BaCl2·2H2O) can be crystallized as colorless crystals.[2]

    Barium chloride can in principle be prepared by the reaction between barium hydroxide or barium carbonate with hydrogen chloride. These basic salts react with hydrochloric acid to give hydrated barium chloride.

    Ba(OH)2 + 2 HCl → BaCl2 + 2 H2O
    BaCO3 + 2 HCl → BaCl2 + H2O + CO2

    Structure and properties

    BaCl2 crystallizes in two forms (

    polymorphs accommodate the preference of the large Ba2+ ion for coordination numbers greater than six.[10] The coordination of Ba2+ is 8 in the fluorite structure[11] and 9 in the cotunnite structure.[12] When cotunnite-structure BaCl2 is subjected to pressures of 7–10 GPa, it transforms to a third structure, a monoclinic post-cotunnite phase. The coordination number of Ba2+ increases from 9 to 10.[13]

    In aqueous solution BaCl2 behaves as a simple

    precipitate of barium sulfate
    .

    BaCl2 + Na2SO4 → 2 NaCl + BaSO4

    This precipitation reaction is used in

    chlor-alkali plants to control the sulfate concentration in the feed brine
    for electrolysis.

    Oxalate effects a similar reaction:

    BaCl2 + Na2C2O4 → 2 NaCl + BaC2O4

    When it is mixed with sodium hydroxide, it gives barium hydroxide, which is moderately soluble in water.

    BaCl2 + 2 NaOH → 2 NaCl + Ba(OH)2

    BaCl2·2H2O is stable in the air at room temperature, but loses one water of crystallization above 55 °C (131 °F), becoming BaCl2·H2O, and becomes anhydrous above 121 °C (250 °F).[2] BaCl2·H2O may be formed by shaking the dihydrate with methanol.[3]

    BaCl2 readily forms

    eutectics with alkali metal chlorides.[3]

    Uses

    Although inexpensive, barium chloride finds limited applications in the laboratory and industry.

    Its main laboratory use is as a reagent for the gravimetric determination of sulfates. The sulfate compound being analyzed is dissolved in water and hydrochloric acid is added. When barium chloride solution is added, the sulfate present precipitates as barium sulfate, which is then filtered through ashless filter paper. The paper is burned off in a muffle furnace, the resulting barium sulfate is weighed, and the purity of the sulfate compound is thus calculated.

    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.[7] It is also used to make red pigments such as Lithol red and Red Lake C. Its toxicity limits its applicability.[citation needed]

    Toxicity

    Barium chloride, along with other water-soluble barium salts, is highly toxic.

    cardiac arrhythmia, muscular paralysis, and death. The Ba2+ ions compete with the K+ ions, causing the muscle fibers to be electrically unexcitable, thus causing weakness and paralysis of the body.[3] Sodium sulfate and magnesium sulfate
    are potential antidotes because they form barium sulfate BaSO4, which is relatively non-toxic because of its insolubility in water.

    Barium chloride is not classified as a human carcinogen.[3]

    References

    1. ^ Chemical Recreations: A Series of Amusing and Instructive Experiments, which May be Performed with Ease, Safety, Success, and Economy ; to which is Added, the Romance of Chemistry : An Inquiry into the Fallacies of the Prevailing Theory of Chemistry : With a New Theory and a New Nomenclature. R. Griffin & Company. 1834.
    2. ^ a b c d "Barium Chloride - an overview | ScienceDirect Topics".
    3. ^ a b c d e f g h "Barium chloride".
    4. ^ Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
    5. ^ a b c NIOSH Pocket Guide to Chemical Hazards. "#0045". National Institute for Occupational Safety and Health (NIOSH).
    6. ^ a b "Barium (soluble compounds, as Ba)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
    7. ^
      ISBN 978-3527306732
      .
    8. ISBN 978-0-08-037941-8
      .
    9. ISSN 0021-8979
      .
    10. ISBN 0-19-855370-6
      .
    11. doi:10.1002/zaac.19784410120
      .
    12. doi:10.1021/j100804a038
      .
    13. doi:10.1107/S0021889895001580
      .
    14. ^ The Merck Index, 7th edition, Merck & Co., Rahway, New Jersey, 1960.

    External links

    Retrieved from "https://en.wikipedia.org/w/index.php?title=Barium_chloride&oldid=1212387211"