Cupric Oxide or black oxide of copper (CuO)

It is obtained by heating copper in air above 9000c
Cu + O2           above 900  →            2CuO

It can also be formed by heating cupric hydro oxide, cupric carbonate or cupric nitrate.
Cu(OH)2         →       CuO + H2O
CuCO3             →           Cuo + CO2
2CuO(NO)3       →       2CuO + 4NO2 + O2


It is a black amorphous solid insoluble in water.

It reacts with acids forming corresponding salts. cuprous chloride.
CuO + 2HCl                →           CuCl2 + H2O
Cupric Chloride
CuO + H2SO           →             CuSO4 + H2O
Copper Sulphate
CuO + 2HNO3                →             Cu(NO3)2 + H2O
Cupric Nitrate

It is reduced by reducing agents like H2 CO etc. to copper.

CuO + H2                      →                    Cu + H2O
CuO + Co                  →             Cu + CO2


  • It is used in making colored glass.
  • It is used to remove sulphur from petroleum.