Chemical elements
  Tungsten
    Isotopes
    Energy
    Production
    Preparation
    Application
    Physical Properties
    Chemical Properties
    Compounds
      Tungsten Hexafluoride
      Tungsten Oxyfluorides
      Tungsten Dichloride
      Double Chlorides of Trivalent Tungsten
      Tungsten Tetrachloride
      Tungsten Pentachloride
      Tungsten Hexachloride
      Tungsten Oxychlorides
      Tungsten Dibromide
      Tungsten Pentabromide
      Tungsten Hexabromide
      Tungsten Chlorobromides
      Tungsten Oxybromides
      Tungsten Di-iodide
      Tungsten Tetra-iodide
      Tungsten Dioxide
      Ditungsten Pentoxide
      Tungsten Trioxide
      Tungstic Acid
      Aluminium Tungstates
      Ammonium Tungstates
      Antimony Tungstates
      Barium Tungstates
      Normal Bismuth Tungstate
      Cadmium Tungstates
      Calcium Tungstates
      Cerium Tungstate
      Chromium Tungstates
      Cobalt Tungstates
      Copper Tungstates
      Indium Tungstate
      Iron Tungstates
      Lanthanum Tungstate
      Lead Tungstates
      Lithium Tungstates
      Magnesium Tungstates
      Manganese Tungstates
      Mercury Tungstates
      Neodymium Tungstate
      Nickel Tungstates
      Platinum Tungstates
      Potassium Tungstates
      Praseodymium Tungstate
      Rubidium Tungstates
      Samarium Tungstate
      Silver Tungstates
      Sodium Tungstates
      Strontium Tungstates
      Thallium Tungstates
      Tin Tungstates
      Uranium Tungstate
      Ytterbium Tungstates
      Yttrium Tungstate
      Zinc Tungstates
      Metatungstic Acid
      Ammonium Metatungstate
      Barium Metatungstate
      Cadmium Metatungstate
      Calcium Metatungstate
      Cerium Metatungstate
      Cobalt Metatungstate
      Lead Metatungstate
      Magnesium Metatungstate
      Mercurous Metatungstate
      Nickel Metatungstate
      Potassium Metatungstate
      Rubidium Metatungstate
      Samarium Metatungstate
      Silver Metatungstate
      Sodium Metatungstate
      Strontium Metatungstate
      Thallous Metatungstate
      Zinc Metatungstate
      Pertungstic Acid
      Tungsten Bronzes
      Potassium Tungsten Bronze
      Lithium Tungsten Bronze
      Lithium Potassium Tungsten Bronze
      Sodium tungsten bronzes
      Tungsten Disulphide
      Tungsten Trisulphide
      Thiotungstates
      Tungsten Diselenide
      Tungsten Triselenide
      Tungsten Phosphides
      Tungsten Diphosphide
      Tritungsten Tetraphosphide
      Tungsten Monophosphide
      Tungsten Subphosphide
      Phosphotungstic Acids
      12-Tungstophosphoric Acid
      11-Tungstophosphates
      21:2-Tungstophosphoric Acid
      10-Tungstophosphoric Acid
      9-Tungstophosphoric Acid
      17:2-Tungstophosphates
      3-Tungstophosphates
      Hypophosphotungstates
      Tungsten Diarsenide
      Tungsten Chloro-arsenide
      12-Tungsto-arsenates
      11-Tungsto-arsenates
      9-Tungsto-arsenic Acid
      17:2-Tungsto-arsenates
      Tungsto-arsenites
      Tritungsten Carbide
      Ditungsten Carbide
      Tungsten Monocarbide
      Tungsten Iron Carbides
      Tungstocyanic Acid
      Ammonium Tungstocyanide
      Calcium Tungstocyanide
      Cadmium Tungstocyanide
      Caesium Tungstocyanide
      Lead Tungstocyanide
      Magnesium Tungstocyanide
      Manganese Tungstocyanide
      Potassium Tungstocyanide
      Rubidium Tungstocyanide
      Silver Tungstocyanide
      Sodium Tungstocyanide
      Strontium Tungstocyanide
      Thallium Tungstocyanide
      Zinc Tungstocyanide
      Tungsticyanic Acid
      Tungsten Sesquisilicide
      Tungsten Disilicide
      Tungsten Trisilicide
      12-Tungstosilicic Acid
      Iso-12-tungstosilicic Acid
      10-Tungstosilicates
      Tungsten Boride
      12-Tungstoboric Acid
      Iso-12-tungstoboric Acid
    Alloys
    PDB 1aor-2rav
    PDB 2rb5-6fit

Barium Tungstates






The anhydrous normal salt, BaWO4, may be obtained by fusing together sodium tungstate, sodium chloride, and barium chloride. It crystallises in colourless octahedratetragonal bipyramidal; a:c = 1:1.6046, of density, according to Zambonini, 6.35. It is only slightly soluble in water. On heating, it first fuses and at high temperatures glows brightly.

Various hydrates have been described. When a solution of barium metatungstate or metatungstic acid is treated with barium hydroxide solution a white gelatinous precipitate is formed which slowly becomes crystalline. According to Pechard, the gelatinous precipitate has the composition BaWO4.2H2O, whilst the crystalline precipitate is BaWO4.H2O. A precipitate, of composition BaWO4.2.5H2O, is obtained by adding barium chloride to a solution of sodium paratungstate containing acetic acid. If barium hydroxide solution is added to a boiling solution of sodium paratungstate until the precipitate no longer redissolves, and the liquid is then allowed to cool, a double salt of sodium and barium (see below) separates; on adding excess of barium hydroxide solution to the mother-liquor a white crystalline precipitate of the pure subhydrated normal tungstate, 2BaWO4.H2O, is obtained.

Barium tungstate has been recommended for use instead of white lead and for colouring porcelain.

Barium ditungstate, BaO.2WO3.H2O, is obtained according to Lefort by double decomposition from solutions of sodium ditungstate and barium acetate, as a white amorphous precipitate, slightly soluble in water. The existence of this compound has been disputed.

Barium paratungstate, 3BaO.7WO3.xH2O, is precipitated on adding excess of a barium salt to a solution of an alkali paratungstate. When dried in the air the salt contains 16H2O; dried over sulphuric acid, 8H2O; dried at 100° C., 4H2O. The double salt, 3Na2O.2BaO.12WO3.24H2O, or 2Na2O.BaO.7WO3.14H2O, separates when excess of barium hydroxide solution is added to a boiling solution of sodium paratungstate and the mixture is allowed to cool.

The acid salt, 4BaO.10WO3.22H2O, is obtained as a white insoluble granular powder when barium chloride is added to a boiling aqueous solution of the corresponding sodium salt.

Barium tritungstate, BaO.3WO3.6H2O, is obtained as a white amorphous precipitate by the addition of cold water to barium metatungstate; a similar precipitate is obtained on mixing solutions of barium acetate and sodium tritungstate, which on drying at 100° C. gives a product of composition BaO.3WO3.4H2O. It dissolves in 300 parts of water at 15° C. Boiling water decomposes it with formation of the insoluble ditungstate and the soluble metatungstate.

An acid tungstate, of composition BaO.8WO3.8H2O, is described by Zettnow, who obtained it by the addition of hydrochloric acid and barium chloride , to a solution of sodium paratungstate which contained sufficient phosphoric acid to prevent precipitation by hydrochloric acid alone; according to Scheibler the precipitate so formed is not of definite composition.

Complex beryllium tungstates corresponding with the formulae: xBeCl2.yBeWO4.zBeO and xBe(NO3)2.yBeWO4.zBeO, have been prepared.


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