Copper(II) chloride is a mild oxidant. It starts to decompose to copper(I) chloride and chlorine gas around  and is completely decomposed near :
The reported melting point of copper(II) chloride of  is a melt of a mixture of copper(I) chloride and copper(II) chloride. The true melting point of  can be extrapolated by using the melting points of the mixtures of CuCl and . Copper(II) chloride reacts with several metals to produce copper metal or copper(I) chloride (CuCl) with oxidation of the other metal. To convert copper(II) chloride to copper(I) chloride, it can be convenient to reduce an aqueous solution with sulfur dioxide as the reductant: