There is a wide variety of copper compounds, whose most common oxidation numbers are +1 and +2, known as cuprous and copper, respectively.
Like other elements, copper is capable of forming binary compounds, i.e., compounds consisting of only two elements, mainly oxides, sulfides, and halides. The oxides are cuprous oxide and copper oxide, and there are many types of sulfides, of which cuprous sulfide and copper sulfide are the more important.
The monovalent halides of copper are cuprous chloride, cuprous bromide and cuprous iodide, and the divalent halides are copper fluoride, copper chloride and copper bromide. If an attempt is made to prepare copper iodide, cuprous iodide and iodine monomers are obtained.
2 Cu 2+ + 4 I – → 2 CuI + I 2
Other simple compounds of copper are copper sulfate, copper nitrate, copper acetate, and copper tetrafluoroborate, all of which have a blue tint (copper acetate blue-green). Insoluble ones are copper hydroxide, cuprous hydroxide, and basic copper carbonate.
