Cuprous oxide is a valence oxide of copper, bright red material, the chemical formula is Cu2O, the relative molecular mass is 143.08. It is almost insoluble in water, in acidsolution disproportionation of cupric and copper, it oxidates gradually into black cupric oxide in the wet air.
  It's used as antipollution paint in the bottom of ship to kill lows forms of marine animal lives ;it can be also used as germicide , coloring agent in red glass . It can also used in manufacturing kinds of nantokites , analytical   regent and rectifier electroplate of electric appliances industry.