Cupric oxide is a kind of +2 valence oxide of copper , black matter, display slightly amphoteric and slightly hygroscopicity, the formula is CuO, relative molecular mass is 79.545 ,density is 6.3～6.9g/cm3, melting point is 1326℃. It can soluble inacid and solution of ammonium chloride and potassium cyanide, insoluble in water and ethanol , dissolve slowly in ammonia water and react with alkaline solutions.
  Mainly used in the industry areas of glass , ceramics , enamel and clours , etc . It can be used as germicide , solar heat absorption material , artificial rainmarking materical ; it can also reduce tobacco tar.