铝三角:Al3+
1 2 5 6
Al(OH)3 3 4 AlO2-
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
2 铁三角:Fe
1 2 5 6
Fe2+ 3 4 Fe3+
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+ g为气体