Chemical elements
    Physical Properties
    Chemical Properties
      Hypovanadous Oxide
      Vanadous Oxide
      Hypovanadic Oxide
      Vanadic Oxide
      Hypovanadous Fluoride
      Vanadous Fluoride
      Vanadium Tetrafluoride
      Vanadium Pentafluoride
      Vanadyl Difluoride
      Vanadium Oxytrifluoride
      Vanadium Dioxyfluoride
      Hypovanadous Chloride
      Vanadous Chloride
      Hypovanadic Chloride
      Divanadyl Chloride
      Vanadium Oxymonochloride
      Vanadyl Dichloride
      Vanadium Oxytrichloride
      Vanadium Oxydichloride
      Vanadous Bromide
      Hypovanadic Bromide
      Vanadium Oxymonobromide
      Vanadyl Dibromide
      Vanadium Oxytribromide
      Hydrated Vanadium Tri-iodide
      Vanadium Suboxide
      Hypovanadous Oxide
      Vanadous Oxide
      Hypovanadic Oxide
      Intermediate Vanadium Oxides
      Vanadium Pentoxide
      Sodium Stannovanadates
      Double Vanadates
      Heteropoly-Acids with Vanadium
      Pervanadic Acid
      Vanadium Monosulphide
      Vanadium Trisulphide
      Vanadium Pentasulphide
      Vanadium Oxysulphides
      Hypovanadous Sulphate
      Vanadous Sulphate
      Vanadyl Sulphites
      Vanadyl Sulphates
      Vanadic Sulphates
      Vanadyl Dithionate
      Ammonium Orthothiovanadate
      Ammonium Pyroxyhexathiovanadate
      Sodium Orthoxytrithiovanadate
      Sodium Orthoxymonothiovanadate
      Vanadium Selenides
      Vanadyl Selenite
      Vanadyl Selenates
      Vanadium Subnitride
      Vanadium Mononitride
      Vanadium Dinitride
      Alkali Vanadyl Nitrites
      Vanadium Nitrates
      Vanadyl Hypophosphite
      Vanadyl Phosphates
      Vanadous Pyrophosphate
      Vanadyl Arsenates
      Vanadium Carbide
      Vanadyl Cyanide
      Potassium Vanadocyanide
      Potassium Vanadicyanide
      Vanadium Ferrocyanides
      Ammonium Vanadyl Thiocyanate
      Vanadium Subsilicide
      Vanadium Disilicide
      Vanadium Boride
    Detection, Estimation
    PDB 1b8j-2i4e
    PDB 2jhr-6rsa


The salts of this class which have hitherto been prepared are all of low vanadium pentoxide content compared with the amount of arsenic pentoxide present. They correspond, therefore, to the luteo vanado-phosphates. Three series are known. The first has the general formula R••O.V2O5.As2O5.xH2O or , where R•• may be Mg, Zn, Cu, or Co. They form yellow crystals which are obtained by the addition of arsenic pentoxide to solutions of the respective vanadates, or by the action of the carbonate of the metal on the free vanado-phosphoric acid. Of the second series only the ammonium and potassium salts are known, viz. (NH4)2O.2V2O5.As2O5.5H2O or , and K2O.2V2O5.As2O5.5H2O or . These also give rise to yellow crystals. The third series has the general formula 2R2O.2V2O5.3As2O5.xH2O, where R2 may be (NH4)2, Ca, Sr, Mg, Zn, Mn, Co, Ni. They result from the action of arsenic pentoxide on solutions of vanadates, and form red crystals which, however, are unstable, and are readily converted by water into compounds of the first series.

The free acid of the first series has been obtained in yellow plates by boiling vanadium pentoxide with a solution of arsenic acid. Its composition is V2O5.As2O5.10H2O or . Recrystallisation of this hydrate from concentrated nitric acid gives a dihydrate, V2O5.As2O5.2H2O, which can be looked upon as the acid . The anhydride, V2O5.As2O5, is obtained by heating the dihydrate to 440° C.

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