Al3+
1 /25\ 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