CUSO4 -> CU(OH)2 -> CUCL2 -> CU(OH)2 -> CUO -> CUCL2 -> AGCL
1. CuSO4+2NaOH = Cu(OH)2+Na2SO4
2. Cu(OH)2+2HCl = CuCl2+2H2O
3. CuCl2+2KOH = Cu(OH)2+2KCl
4. Cu(OH)2(t) = CuO+H2O
5. CuO+2HCl = CuCl2+H2O
6. CuCl2+2AgNO3 = 2AgCl+Cu(NO3)2