What does the electrolysis of copper in a salt solution produce?

Question

copper oxide, copper chloride, copper chlorate?

Answer 1

If we are assuming that the salt in question is sodium chloride, and that the anode of the cell is made of copper metal, then copper(II) chloride will be produced (in solution).

You will get oxygen and chlorine gas coming off of the anode (Positive electrode).  These can oxidize the copper to form copper chloride and oxychlorides.  Copper(II) chloride is soluble in water, so if this forms, you will get copper metal deposited at the cathode (negative electrode).