Copper(I) oxide
Copper(I) oxide, also known as cuprous oxide, is a chemical compound. Its chemical formula is Cu2O. It contains copper in its +1 oxidation state. It also contains oxide ions.
Properties
Copper(I) oxide is a red solid. It can also be yellow, but not commonly. It does not dissolve in water. It turns into copper(II) oxide when in air. It dissolves in ammonia to make a colorless complex. This is oxidized to a blue complex of copper(II). It dissolves in concentrated hydrochloric acid. It also dissolves in concentrated sulfuric acid to make copper(II) sulfate and nitric acid to make copper(II) nitrate.
Occurrence
Copper(I) oxide is found in the ground. It is a copper ore.
Preparation
Copper(I) oxide is made by heating copper in air. Some copper(II) oxide is also made. It can also be made by reducing copper(II) oxide or other copper(II) compounds. It is the result of a test for sugars. Green copper(II) chloride is reduced to red copper(I) oxide when a sugar is present.
Uses
Copper(I) oxide is used as a semiconductor. It is also used as a pigment and fungicide. It can be used to stop things from growing on ships.
Copper(I) Oxide Media
Pourbaix diagram for copper in uncomplexed media (anions other than OH− not considered). Ion concentration 0.001 mol/kg water. Temperature 25 °C.
Large crystal of the mineral form of copper(I) oxide (cuprite).
