Copper(II) oxide

From Freepedia

Copper(II) oxide or cupric oxide (CuO) is the higher oxide of copper. It is a black solid which melts above 1200 °C with some loss of oxygen. It can be formed by heating copper in air, but in this case it is formed along with copper(I) oxide; thus, it is better prepared by heating copper(II) nitrate, copper(II) hydroxide or copper(II) carbonate:

CuCO₃ → CuO + CO₂

Copper(II) oxide is a basic oxide, so it dissolves in mineral acids such as hydrochloric acid, sulfuric acid or nitric acid to give the corresponding copper(II) salts:

CuO + 2 HNO₃ → Cu(NO₃)₂ + H₂O

It can also be reduced to copper metal using hydrogen or carbon monoxide:

H₂ + CuO → Cu + H₂O

See also

• copper(I) oxide