Chemical elements
  Selenium
    Isotopes
    Energy
    Production
    Application
    Allotropy
    Colloidal
    Physical Properties
    Chemical Properties
      Hydrogen Selenide
      Selenium Fluorides
      Selenium Monochloride
      Selenium Tetrachloride
      Selenium Monobromide
      Selenium Tetrabromide
      Selenium Chlorobromides
      Selenium Oxyfluoride
      Selenium Oxychloride
      Sulphur Selenium Oxytetrachloride
      Selenium Oxybromide
      Chloroselenic Acid
      Selenium Dioxide
      Selenious Acid
      Selenium Trioxide
      Selenic Acid
      Selenates
      Perselenic Acid
      Selenium Sulphoxide
      Selenotrithionic Acid
      Diselenotrithionic Acid
      Selenopentathionic Acid
      Selenium Nitride
      Nitrosylselenic Acid
      Phosphorus Subselenide
      Phosphorus Monoselenide
      Tetraphosphorus Triselenide
      Phosphorus Triselenide
      Phosphorus Pentaselenide
      Phosphorus Chloroselenide
      Selenophosphates and Oxyselenophosphates
      Carbon Diselenide
      Carbon Subselenides
      Carbon Oxyselenide
      Carbon Sulphidoselenide
      Cyanogen Monoselenide
      Cyanogen Diselenide or Selenocyanogen
      Cyanogen Triselenide
      Selenocyanic Acid
      Ammonium Selenocyanate
      Caesium Triselenocyanate
      Copper Selenocyanate
      Lead Selenocyanate
      Magnesium Selenocyanate
      Mercurous Selenocyanate
      Mercuric Selenocyanate
      Potassium Selenocyanate
      Silver Selenocyanate
      Sodium Selenocyanate
      Zinc Selenocyanate
      Silicon Selenide
    Detection and Estimation

Selenium Oxyfluoride, SeOF2






When dry hydrogen fluoride vapour is passed over selenium dioxide, the former is rapidly absorbed, the product liquefying and becoming warm. From this liquid Prideaux has isolated a product approximating to the composition SeO2.5HF, but a definite oxyfluoride does not appear to be obtainable by this method. The Selenium Oxyfluoride, SeOF2, may be prepared by passing selenium oxychloride vapour over silver fluoride at 140° to 200° C.; the reaction begins suddenly, and copious fumes are evolved which may be condensed to a colourless liquid of density 2.67 and boiling-point 124° C. This solidifies to an ice-like mass which melts at 4.6° C. Glass is readily attacked by the liquid or vapour, a white deposit of selenium dioxide being formed:

2SeOF2 + SiO2 = 2SeO2 + SiF4.

The reaction with red phosphorus is violent and accompanied by inflammation, the products being similar to those described with the tetrafluoride. The oxyfluoride is hydrolysed by water with evolution of heat.


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