1 Al3+ + 3OH- = Al(OH)3 (s) 
2 Al(OH)3 + 3H+ = Al3+ + 3H2O 
3 Al(OH)3 + OH- = AlO2- + 2H2O 
4 AlO2- + H+ + H2O = Al(OH)3 (s) 
5 Al3+ + 4OH- = AlO2- + 2H2O 
6 AlO2-+ 4H+ = Al3+ + 2H2O s 为沉淀 
1 Fe + 2H+ = Fe2+ + H2 (g) 
2 Fe2+ + Zn = Fe + Zn2+ 
3 2Fe2+ + Cl2 = 2Fe3+ + 2Cl- 
4 2Fe3+ + Fe = 3Fe2+ 还可以和Cu反应 
5 2Fe + 3Cl2 = 2Fe3+ + 6Cl- 
6 2Fe3+ + 3Zn = 2Fe + 3Zn2+
