Copper (Cu) is reacted with sulfuric acid (H2SO4) to form copper sulfate (CuSO4). This compound can then react with sodium chloride (NaCl) to form sodium sulfate (Na2SO4) and copper chloride (CuCl2). Finally, if barium chloride (BaCl2) is added, barium sulfate (BaSO4) will be formed as a white precipitate, while copper chloride remains in solution.