Chemical elements
  Cobalt
    Isotopes
    Energy
    Production
    Preparation
    Application
    Physical Properties
    Chemical Properties
    Compounds
      Cobaltous Fluoride
      Hydrated Cobaltous Fluoride
      Cobaltic Fluoride
      Cobaltous Chloride
      Cobaltic Chloride
      Cobaltous Bromide
      Cobaltous Iodide
      Cobalt Oxy-fluoride
      Cobalt Oxy-chloride
      Cobalt Chlorate
      Cobalt Perchlorate
      Cobalt Bromate
      Cobalt Iodate
      Cobalt Monoxide
      Cobaltous Hydroxide
      Tri-cobalt Tetroxide
      Cobalt Sesquioxide
      Hydrated Cobaltic Oxide
      Cobalt Dioxide
      Cobalt Monosulphide
      Tricobalt Tetrasulphide
      Cobalt Sesquisulphide
      Cobalt Disulphide
      Cobalt Polysulphides
      Cobaltous Sulphite
      Cobaltic Sulphite
      Cobalt Thiosulphate
      Cobalt Dithionate
      Cobalt Sulphate
      Ammonium Cobalt Sulphate
      Potassium Cobalt Sulphate
      Cobaltic Sulphate
      Ammonium Cobalt Alum
      Potassium Cobalt Alum
      Cobalt Subselenide
      Cobalt Selenide
      Tricobalt Tetraselenide
      Cobalt Sesquiselenide
      Cobalt Diselenide
      Cobalt Selenite
      Cobalt Diselenite
      Cobalt Triselenite
      Cobaltous Selenate
      Cobaltic Selenate
      Cobalt Sesquitelluride
      Cobalt Tellurite
      Cobalt Chromate
      Cobalt Dichromate
      Double Chromates
      Cobalt Molybdate
      Cobalt Nitride
      Cobalt Azoimide
      Nitro-cobalt
      Potassium Cobaltous Nitrite
      Potassium Cobalti-nitrite
      Sodium Cobalti-nitrite
      Sodium Potassium Cobalti-nitrite
      Ammonium Cobalti-nitrite
      Barium Cobalti-nitrite
      Red Sodium Cobalti-nitrite
      Red Barium Cobalti-nitrite
      Red Strontium Cobalti-nitrite
      Zinc Cobalti-tri-nitrite
      Silver Cobalti-tri-nitrite
      Cobalto-cobalti-tri-nitrite
      Cobaltous Nitrate
      Cobaltic Nitrate
      Cobalt Subphosphide
      Cobalt Sesquiphosphide
      Tri-cobalt Diphosphide
      Tetra-cobalt Triphosphide
      Cobalt Hypophosphite
      Cobalt Phosphite
      Cobalt Metaphosphate
      Tri-cobalt Di-arsenide
      Cobalt Monarsenide
      Cobalt Tri-arsenide
      Cobalt Arsenites
      Cobalt Arsenates
      Cobalt Antimonide
      Cobalt Di-antimonide
      Cobalt Antimonate
      Cobalt Thio-antimonite
      Cobalt Carbide
      Cobalt Tetra-carbonyl
      Cobaltous Carbonate
      Basic Cobaltous Carbonates
      Cobaltic Carbonate
      Cobaltous Cyanide
      Potassium Cobalto-cyanide
      Nickel Cobalto-cyanide
      Cobaltous Cobalto-cyanide
      Zinc Cobalto-cyanide
      Cobalti-cyanic Acid
      Ammonium Cobalti-cyanide
      Barium Cobalti-cyanide
      Potassium Cobalti-cyanide
      Cobalt Cobalti-cyanide
      Cupric Cobalti-cyanide
      Ferrous Cobalti-cyanide
      Nickel Cobalti-cyanide
      Silver Cobalti-cyanide
      Lead Cobalti-cyanide
      Sodium Cobalti-cyanide
      Cobalt Thiocyanate
      Cobalt Subsilicide
      Cobalt Monosilicide
      Cobalt Disilicide
      Cobalt Orthosilicate
      Cobalt Fluosilicate
    PDB 1a0c-1epy
    PDB 1et4-1k7y
    PDB 1k98-1r6x
    PDB 1r8k-1v9b
    PDB 1vl3-212d
    PDB 222d-2eff
    PDB 2ehd-2j3z
    PDB 2j4j-2r1p
    PDB 2r2s-331d
    PDB 362d-3fqw
    PDB 3ft6-3igy
    PDB 3igz-3o0n
    PDB 3o0o-4req
    PDB 4xim-9icb

Cobaltous Bromide, CoBr2






Cobaltous Bromide, CoBr2, may be obtained as a green mass by passing bromine vapour or a mixture of bromine and hydrogen bromide over heated cobalt; by heating the hydrated salt to 130° C.; and also by addition of the calculated quantity of dry bromine to finely divided cobalt under ether. The green salt, CoBr2.(C2H5)2O, is produced which, on heating, yields CoBr2. The salt may be purified by sublimation in a current of hydrogen bromide. The product is green, crystalline, of density 4.91. It begins to be reduced by dry hydrogen at about 350° C. The reaction is more rapid at higher temperatures, but is accompanied by partial sublimation. With moist hydrogen the reduction begins at 250° C.

The salt deliquesces to a dark red liquid upon exposure to air. The solution, which also results when metallic cobalt is exposed to the prolonged action of bromine and water, yields, on concentration over sulphuric acid, splendid purple-red prismatic crystals of the hexahydrate, CoBr.6H2O. These melt at 47-48° C. At 100° C. they fuse to a deep blue liquid, evolving water, and leaving on cooling purplish blue crystals of the dihydrate, CoBr2.2H2O. When heated to 130° C., the salt dries up to an opaque, amorphous, vivid green mass of anhydrous bromide.

In addition to the foregoing, several other hydrates are known, their formulae and appearance, together with those above cited, being as follow:

CoBr2.6H2Ored prisms m.pt. 47-48° C.
CoBr2.5.5H2Orose-coloured
CoBr2.5H2Opink
CoBr2.4H2Oreddish-violet m.pt. 70-71° C.
CoBr2.2H2Opurple
CoBr2.H2Oblue
CoBr2.0.5H2O?
CoBr2green


On exposing the anhydrous salt to ammonia gas, as also by passing ammonia into a solution of cobalt bromide in methyl acetate, the hexammoniate, CoBr2.6NH3, is obtained as pale rose-red crystals. These lose ammonia on heating, becoming light blue at 120° C. and having the composition CoBr2.2NH3.

The solubility of cobalt bromide in water is as follows:

Temperature ° С597597
Grams CoBr2 in 100 grams solution66.766.868.1


When dissolved in organic liquids the molecular weight, as determined by ebullioscopic methods, appears to correspond to the single formula, CoBr2.


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