Chemical elements
  Uranium
    Isotopes
    Energy
    Production
    Application
    Physical Properties
    Chemical Properties
    Compounds
      Uranium Difluoride
      Uranium Tetrafluoride
      Uranous Oxyfluoride
      Uranium Hexafluoride
      Uranyl Fluoride
      Uranium Trichloride
      Uranium Tetrachloride
      Uranium Pentachloride
      Uranyl Chloride
      Uranyl Chlorate
      Uranyl Perchlorate
      Uranium Tetrabromide
      Uranyl Bromide
      Uranium Tetra-iodide
      Uranyl Iodide
      Uranyl Iodate
      Uranous Oxide
      Uranous Hydroxide
      Uranium Pentoxide
      Urano-uranic Oxide
      Uranium Trioxide
      Ammonium Diuranate
      Ammonium Hexa-uranate
      Hydroxylamine Uranate
      Hydroxylamine Potassio-uranate
      Barium Uranate
      Barium Diuranate
      Bismuth Uranate
      Iron Uranate
      Lithium Uranate
      Potassium Uranate
      Potassium Diuranate
      Potassium Tetra-uranate
      Potassium Hexa-uranate
      Rubidium Uranate
      Silver Diuranate
      Sodium Uranate
      Sodium Diuranate
      Sodium Triuranate
      Sodium Penta-uranate
      Strontium Uranate
      Zinc Uranate
      Peruranic acid
      Ammonium Peruranate
      Barium Peruranates
      Lithium Peruranate
      Nickel Peruranate
      Potassium Peruranate
      Sodium Peruranates
      Uranium Monosulphide
      Uranium Sesquisulphide
      Uranium Disulphide
      Uranium Oxysulphide
      Uranyl Sulphide
      Uranium Sulphite
      Uranyl Sulphite
      Complex Uranyl Sulphites
      Uranium Sulphate
      Uranium Dithionates
      Uranyl Sulphate
      Uranyl Pyrosulphate
      Uranyl Thiosulphate
      Uranyl Dithionate
      Uranium Sesquiselenide
      Uranium Diselenide
      Uranyl Selenide
      Uranyl Selenite
      Uranyl Selenate
      Uranium Telluride
      Uranium Nitrides
      Uranous Nitrate
      Uranyl Nitrate
      Uranium Monophosphide
      Uranous Phosphide
      Uranyl Hypophosphite
      Uranyl Phosphite
      Uranous Phosphates
      Uranyl Phosphates
      Complex Uranyl Phosphates
      Uranyl Aminophosphates
      Uranous Arsenide
      Uranyl Metarsenite
      Uranous Arsenate
      Uranyl Arsenates
      Complex Uranyl Arsenates
      Uranous Antimonide
      Uranous Antimonate
      Uranium Carbide
      Complex Uranyl Carbonates
      Ammonium Uranyl Carbonate
      Calcium Uranyl Carbonate
      Potassium Uranyl Carbonate
      Sodium Uranyl Carbonate
      Thallium Uranyl Carbonate
      Potassium Uranyl Ferrocyanide
      Uranyl Platinocyanide
      Uranyl Cyanate
      Uranyl Thiocyanate
      Uranium Silicide
      Uranium Boride
      Uranyl Perborate
    PDB 1anv-3pu4

Uranyl Iodate, UO2(IO3)2






Uranyl Iodate, UO2(IO3)2, is obtained by precipitation of a solution of uranyl nitrate by means of sodium iodate in presence of a large excess of nitric acid. According to Ditte, the anhydrous salt is obtained as yellow crystals by mixing the boiling solutions and crystallising at 60° C. A pentahydrats, UO2(IO3)2.5H2O, is obtained when iodic acid or sodium iodate is added to a cold solution of uranyl acetate. When heated to 250° C. the iodate decomposes, yielding iodine and urano-uranic oxide. According to Artmann, however, the iodate does not exist in the anhydrous condition, but only as the mono- and di-hydrates, the nature of the product in the precipitation of uranyl nitrate by means of sodium iodate depending upon the conditions. From hot and acid solutions the monohydrate, UO2(IO3)2.H2O, is obtained, while from cold solutions the dihydrate, UO2(IO3)2.2H2O, is precipitated. The monohydrate exists in two modifications: a rhombic prismatic form, stable at ordinary temperatures, of density 5.220 at 18° C., and a pyramidal form of density 5.052 at 18° C. The former is converted into the latter by boiling with water, while the reverse change takes place slowly at ordinary temperatures. The two varieties differ in solubility, 100 c.c. of water dissolving at 18° C. 0.1049 gram of the prismatic form and 0.1214 gram of the pyramidal form. The di-hydrate has a lighter yellow colour and crystallises in irregular aggregates. It is slightly soluble in water, the solution being strongly acid. When heated, uranyl iodate retains one molecule of water and does not become anhydrous. Artmann, therefore, suggests that the molecule of the compound should be represented by the formula (OH)(UO2)IO3.IO3H., i.e.



The potassium salt, K(UO2)(IO3)3.3H2O, is precipitated when potassium iodate is added in large excess to uranyl iodate solution as a light yellow powder of density 3.706. It is sparingly soluble in and is hydrolysed by water; it is converted into uranyl iodate by excess of uranyl nitrate.


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