Chemical elements
  Barium
    Isotopes
    Energy
    Production
    Application
    Physical Properties
    Chemical Properties
      Barium Hydride
      Barium Subfluoride
      Barium Fluoride
      Acid Barium Fluoride
      Barium Subchloride
      Barium Chloride
      Barium Bromide
      Barium Perbromides
      Barium Iodide
      Barium Periodides
      Barium Mixed Halides
      Barium Mixed Perhalides
      Barium Oxychloride
      Barium Hypochlorite
      Barium Chlorite
      Barium Chlorate
      Barium Perchlorate
      Barium Oxybromide
      Barium Hypobromite
      Barium Bromate
      Barium Perbromate
      Barium Oxyiodide
      Barium Iodate
      Barium Periodate
      Barium Manganites
      Barium Manganate
      Barium Permanganate
      Barium Suboxide
      Barium Oxide
      Barium Hydroxide
      Barium Peroxide
      Barium Peroxyhydrate
      Barium Tetroxide
      Barium Sulphide
      Barium Hydrosulphide
      Barium Polysulphides
      Barium Hydroxyhydrosulphide
      Barium Oxysulphides
      Barium Sulphite
      Barium Thiosulphate
      Barium Dithionate
      Barium Trithionate
      Barium Tetrathionate
      Barium Pentathionate
      Barium Sulphate
      Acid Barium Sulphates
      Barium Pyrosulphate
      Barium Persulphate
      Barium Selenide
      Barium Selenite
      Barium Selenate
      Acid Barium Selenate
      Barium Telluride
      Barium Tellurite
      Barium Tellurate
      Barium Chromite
      Barium Chromate
      Barium Dichromate
      Barium Potassium Trichromate
      Barium Chlorochromate
      Barium Perchromate
      Barium Molybdate
      Barium Permolybdate
      Barium Tungstate
      Barium Uranate
      Barium Diuranate
      Barium Peruranate
      Barium Nitride
      Barium Azide
      Barium Hexammoniate
      Barium Ammonium
      Barium Amide
      Baramide
      Barium Amidosulphonate
      Barium Imide
      Barium Imidosulphonate
      Barium Hyponitrite
      Barium Nitroxysulphite
      Barium Nitrososulphate
      Barium Nitrohydroxylaminate
      Barium Nitrite
      Barium Nitrate
      Barium Phosphide
      Barium Dihydrohypophosphite
      Barium Hydrophosphite
      Barium Hypophosphate
      Barium Orthophosphates
      Barium Pyrophosphate
      Barium Metaphosphate
      Basic Barium Phosphates
      Barium Thiophosphites
      Barium Thiophosphates
      Barium Selenophosphates
      Barium Azophosphates
      Barium Phosphimates
      Barium Arsenide
      Barium Orthoarsenite
      Barium Pyroarsenite
      Barium Orthoarsenates
      Barium Pyroarsenate
      Barium Thioarsenites
      Barium Thioarsenates
      Barium Sodium Selenoxyarsenate
      Barium Metantimonate
      Barium Thioantimonites
      Barium Chloroantimonite
      Barium Orthothioantimonate
      Barium Hypovanadate
      Barium Vanadates
      Barium Metapervanadate
      Barium Niobate
      Barium Tantalate
      Barium Pertantalate
      Barium Carbide
      Barium Carbonyl
      Barium Formate
      Barium Acetate
      Barium Oxalate
      Barium Carbonate
      Barium Thiocarbonate
      Barium Percarbonate
      Barium Cyanide
      Barium Cyanamide
      Barium Cyanate
      Barium Cyanurate
      Barium Thiocyanate
      Barium Selenocyanate
      Barium Silicide
      Barium Silicates
      Barium Fluosilicate
      Barium Stannate
      Barium Orthoplumbate
      Barium Titanate
      Barium Peroxide Pertitanate
      Barium Pertitanate
      Barium Fluoroxytitanate
      Barium Zirconate
      Barium Boride
      Barium Borates
      Barium Fluorborate
      Barium Perborate
      Barium Aluminates
      Barium Ferrite
      Barium Ferrate
      Barium Gobaltite
      Barium Dinickelite
      Barium Platinate
    Detection of Barrium
    PDB 1djh-3iqp
    PDB 3iqr-4e7y

Barium Chloride, BaCl2






Barium Chloride, BaCl2, was first described by Scheele. It may be formed from the metal by direct combination with chlorine; from barium oxide by the action of chlorine at red heat, or of hydrochloric acid; from barium sulphate by heating to redness in hydrochloric acid gas, or by fusing with excess of ammonium chloride; and from barium hydroxide, carbonate, or sulphide by the action of aqueous hydrochloric acid, evaporation to dryness, and fusion in an atmosphere of hydrochloric acid gas to remove the last traces of moisture.

On a commercial scale it may be prepared from the sulphate, barytes, by fusion with calcium chloride alone, or with carbon or iron, or a mixture of manganese chloride and carbon; by the action of hydrochloric acid on a mixture of barium sulphate and carbon at red heat; or, finally, by reduction to sulphide and fusion with magnesium chloride under pressure. If witherite form the starting-point, it may be fused with ammonium chloride or calcium chloride.

Barium chloride may be purified by repeated precipitation with alcohol.

The heat of formation of barium chloride is 197.08 Cal. The density of the salt dried at 220° C. is 3.856 at 24° C. The melting point is 958.9° C., and there is a transition point to another form at 924.5° C. The specific heat is 0.0902.

The specific electrical conductivity at the melting-point is 1.91 reciprocal ohms, and increases to 2.31 at 1100° C.

The highest value found for the decomposition potential of barium chloride is 3.3 volts, but this is probably too low owing to the difficulty of avoiding polarisation. At 650° C. the value for barium chloride, mixed with lithium chloride to reduce the temperature of fusion, is 3.05 volts, and at 750° C., 1.45 volts.

By heating with bromine at 200°-300° C., part of the chlorine is removed. At the temperature of fusion it is partly decomposed by oxygen or by sulphur with loss of chlorine. It is decomposed by water vapour with the formation of hydrochloric acid, but less readily than the other alkaline earth chlorides.

Barium chloride is readily soluble in water, and the heat of solution is 1.92 Cal. Its solubility has been studied by a number of investigators, and the following values were given by Mulder: -

Temperature, °C.102030405060708090100
Grams BaCl2 in 100 grams water.33.335.738.240.843.646.449.452.455.658.8


The solubility is considerably diminished in presence of hydrochloric acid, sodium chloride, or barium nitrate, due to the action of a common ion. Engel found that, whereas 10 c.c. of pure water dissolve 28.9 milli-equivalents of barium chloride, 10 c.c. of hydrochloric acid solution, containing 50-5 milli-equivalents of acid, only dissolve 0.29 milli-equivalents of the salt.

Values for the solubility in different water-alcohol mixtures have also been determined, but it is almost insoluble in absolute alcohol. It is soluble in methyl alcohol to the extent of 2.18 parts in 100 parts of alcohol at 15.5° C.

Determinations of the transport number of the barium ion in chloride solutions of different concentrations have been made, and seem to indicate the presence of the complex ions BaCl3' and BaCl4'. Powdered quartz absorbs barium chloride from its solutions.


Hydrates of Barium Chloride

Two hydrates of barium chloride, the mono- and the di-hydrate, have been isolated. On the ground of vapour pressure measurements, the existence of a hexahydrate, only stable in contact with the aqueous solution below about 10° C., has been suggested, but the evidence scarcely seems sufficient to justify this supposition.

Barium Chloride Dihydrate, BaCl2,2H2O

Barium Chloride Dihydrate, BaCl2.2H2O, separates from solution at ordinary temperatures in colourless monoclinic crystals of density 3.097 at 24° C. and specific heat 0.171. The vapour pressure at 25° C. is 5.8 mm. The heat of solution is -4.93 Cal., and the heat of hydration is 7.00 Cal. The dihydrate melts at 100° C., giving the anhydrous salt.

Barium Chloride Monohydrate, BaCl2,H2O

The existence of Barium Chloride Monohydrate, BaCl2.H2O was first suspected by Thomsen, because he found that the heat of reaction of anhydrous barium chloride with one grm.-mol. of water, 3 17 Cal., is less than half the heat of reaction with two grm.-mol. Vapour pressure measurements also indicate its existence.

It may be formed by heating the dihydrate at 60°-65° C., or by shaking the dihydrate with 99 per cent, of methyl alcohol, filtering at once through a Buchner funnel to remove undissolved salt, and leaving to crystallise. After a few minutes the monohydrate separates from solution in colourless rhombic plates and can be dried over calcium chloride in vacuo. The vapour pressure of the monohydrate at 25° C. is 2.5 mm.

Barium chloride may be used for softening boiler water, especially for removing permanent hardness.

Addition Compoundsof Barrium Chloride

Barium chloride absorbs ammonia under pressure, but gives it up again when exposed to the atmosphere. The compound, BaCl2.4NH3, is formed. It has a dissociation pressure of 541 mm. of mercury at 0° C., and 1850 at 28.4° C. Ammonia also forms a compound with the double salt of mercury cyanide and barium chloride, 2Hg(CN)2.BaCl2.4NH3. Several addition compounds with ammonia derivatives have been isolated, with hydroxyiamine, BaCl2.NH2OH.2H2O and BaCl2.NH2OH, with glycine, BaCl2.2NH2CH2COOH, and with monobetaine, BaCl2.C5H11O2N.4H2O.

Barium chloride forms mixed crystals in all proportions with lead chloride.



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