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

Cobalt Iodate, Co(IO3)2






Cobalt Iodate, Co(IO3)2, was known to Rammelsberg in 1838, and was further studied by Fullerton and Ditte, the last-named investigator claiming to have prepared the anhydrous salt, and salts with 2, 3, 4, and 5 molecules of water, whilst Fullerton describes a hexahydrate.

Meusser confirms the existence of the anhydrous salt, and of the di- and tetra-hydrates, but throws doubt on the existence of the tri-, penta-, and hexa-hydrates.

The anhydrous salt may be obtained by maintaining for a prolonged period at 80° to 90° C. a mixed solution of cobalt nitrate and alkali iodate in the presence of free nitric acid. It is also formed at ordinary temperatures by mixing saturated solutions of cobalt nitrate and alkali iodate and agitating with a glass rod the flocculent, rose-coloured, hydrated precipitate, when it yields the blue-violet anhydrous compound. The salt is also produced by heating the same solutions from two to three hours in a glass tube at 120° C.

Anhydrous cobalt iodate yields microscopic needles, blue-violet in colour, and which on heating become dark blue in colour, but regain their original hue on cooling. Below 200° C. decomposition sets in, iodine and oxygen being evolved.

The dihydrate, Co(IO3)2.2H2O, is obtained by mixing equivalent amounts of cobalt nitrate and alkali iodate (or free iodic acid) in ten times their weight of water and allowing to crystallise at 30° C. Microscopic crystals of lilac hue are obtained, which are the stable form of the salt up to 68° C.

The tetrahydrate, Co(IO3)2.4H2O, is obtained as red crystals by evaporating a 5 per cent, solution containing equivalent proportions of cobalt nitrate and iodic acid at 0° to 20° C. When agitated for a prolonged period with water at 30° C. the tetrahydrate yields the dihydrate.

The various solubilities of the hydrates of cobalt iodate at different temperatures are as follow:

Tetrahydrate, Co(IO3)2.4H2O
Temperature ° C01830506065
Grams Co(IO3)2 per 100 grams solution0.540.831.031.461.862.17
Dihydrate, Co(IO3)2.2H2O
Temperature ° С018305075100
Grams Co(IO3)2 per 100 grams solution0.320.450.520.670.841.02
Anhydrous Salt, Co(IO3)2
Temperature °C.18305075100
Grams Co(IO3)2 per 100 grams solution1.030.890.850.750.69


..
. hydrates of cobalt iodate solubility.
. Solubility curves of the hydrates of cobalt iodate.
These results are shown graphically in Fig., and are interesting as showing the rapid rise in solubility of the tetrahydrate with increase of temperature, and the simultaneous fall in solubility of the anhydrous salt.


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