CuCI2--Cu(OH)2--CuO--CuSO4--BaSO4

CuCl2+2KOH --- Cu(OH)2+2KCl

Cu(OH)2 --- CuO+H2O

CuO+H2So4 --- CuSo4+H2O

CuSo4+Ba(OH)2 --- BaSo4+Cu(OH)2