Fe-FeCl2-FeCl3-Fe(OH)Cl2-Fe(OH)3
Fe + 2HCl = FeCl2 + H2
2FeCl2 + Cl2 = 2FeCl3
FeCl3 + H2O = FeOHCl2 + HCl
FeOHCl2 + 2NaOH = Fe(OH)3 + 2NaCl