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.

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