What is the oxidation number of copper?

1 Answer
Jul 2, 2014

The oxidation number of copper depends on its state.

The oxidation number of metallic copper is zero.

In its compounds, the most common oxidation number of Cu is +2. Less common is +1. Copper can also have oxidation numbers of +3 and +4.

ON = +2: Examples are CuCl₂, CuO, and CuSO₄. See, for example


ON = +1: Examples are CuCl, Cu₂O, and Cu₂S.

ON = +3: Examples are KCuO₂ and K₃CuF₆.

ON = +4: An example is Cs₂CuF₆.

Hope this helps.