Chemical elements
  Carbon
    Isotopes
    Energy
    Production
    Application
    Physical Properties
    Chemical Properties
      Methane
      Ethylene
      Acetylene
      Coal-Gas
      Carbon Tetrafluoride
      Tetrafluoromethane
      Carbon Tetrachloride
      Tetrachloromethane
      Carbon Tetrabromide
      Tetrabromomethane
      Carbon Tetraiodide
      Tetraiodomethane
      Carbon Oxychloride
      Carbonyl Chloride
      Phosgene
      Carbon Oxybromide
      Carbonyl Bromide
      Carbon Suboxide
      Carbon Monoxide
      Carbon Dioxide
      Percarbonic Acid
      Carbamic Acid
      Carbamide
      Urea
      Carbon Disulphide
      Carbonyl Sulphide
      Carbon Oxysulphide
      Thiocarbonyl Chloride
      Thiocarbonic Acid
      Thiocarbamic acid
      Thiourea
      Thiocarbamide
      Perthiocarbonates
      Carbon Monosulphide
      Carbon Subsulphide
      Carbon Sulphidoselenide
      Carbon Sulphidotelluride
      Carbon Nitrides
      Cyanogen
      Dicyanogen
      Hydrocyanic Acid
      Prussic Acid
      Cyanogen Chloride
      Chlorocyanogen
      Cyanogen Bromide
      Bromocyanogen
      Cyanogen Iodide
      Iodocyanogen
      Polymerised Cyanogen Halides
      Cyanamide
      Cyanic Acid
      Cyanuric Acid
      Cyamelide
      Fulminic Acid
      Thiocyanic Acid
      Sulphocyanic Acid
      Isoperthiocyanic Acid
      Cyanogen Sulphide
      Thiocyanic Anhydride
    Diamonds
    Graphite
    Amorphous Carbon
    Coal

Thiourea, CS(NH2)2






Thiocarbamide, Thiourea, CS(NH2)2. - Thiourea is formed by heating ammonium thiocyanate to 140° C., this salt undergoing an isomeric change analogous to that produced in ammonium cyanate by heat:

NH4SCNSC(NH2)2.

At the same time some guanidine thiocyanate, NH:C(NH2)2.HSCN, is produced, though a larger proportion of this latter substance is formed at 170°-180° C. The thiourea is freed from guanidine thiocyanate and unchanged ammonium thiocyanate by cold water, in which the thiourea is but sparingly soluble; it is then purified by recrystallisation from water.

A better method of preparation consists in heating carbon disulphide (6 grams) with ammonium carbonate (8 grams) in a sealed tube at 160° C., when the yield is quantitative.

Thiourea crystallises in rhombic prisms, and dissolves in eleven times its weight of cold water. When heated with water to 140° C. it reverts to ammonium thiocyanate. It forms salts analogous to those of urea; the most characteristic of these is the nitrate, CS(NH2)2.HNO3.


© Copyright 2008-2012 by atomistry.com