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

Vanadium Pentasulphide, V2S5

Vanadium pentasulphide is prepared by heating vanadium trisulphide with slight excess over the calculated quantity of sulphur at 400° C. for several hours; excess of sulphur is finally removed with carbon disulphide. This reaction is reversible, for on being heated in the absence of air the pentasulphide loses sulphur and re-forms the trisulphide. Heated in air it forms vanadium pentoxide. It is a black powder, of density 3.0. It does not differ from the lower sulphides in its behaviour towards acids; colourless ammonium sulphide also dissolves it to give the purple solution given by the other sulphides, but yellow ammonium sulphide produces a brownish-red solution. It differs markedly from the other sulphides in being readily dissolved by caustic soda, especially on warming, and in this respect acts in a manner comparable to vanadium pentoxide. Several thiovanadates analogous to the vanadates are known.

The order of stability of the sulphides of vanadium is not the same as that of the oxides; for whilst in the oxygen series the penta-compound is stable at a red heat, in the sulphur series the penta-compound is converted into the trisulphide at this temperature. Again, the trioxide is permanent in hydrogen at intense redness, whilst the trisulphide is reduced to the monosulphide under similar conditions.

A sulphide in which the vanadium is tetravalent, corresponding to the oxide VO2, has not hitherto been prepared.

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