1) CuCl2 -> Cu(OH)2 -> CuO
CuCl2 + 2NaOH = Cu(OH)2 + 2NaCl
Cu(OH)2 = CuO + H2O
2) Al2(SO4)3 -> Al(OH)3 - >AlCl3
Al2(SO4)3 + 6NaOH = 2Al(OH)3 + 3Na2SO4
Al(OH)3 + 3HCl = AlCl3 + 3H2O
3) ZnCl2 -> Zn(OH)2 -> ZnO
ZnCl2 + 2KOH = Zn(OH)2 + 2KCl
Zn(OH)2 = ZnO + H2O
4) Na -> NaOH ->Na2SO4
2Na + 2H2O = 2NaOH + H2
2NaOH + SO3 = Na2SO4 + H2O