Al2O3→Al2(SO4)3→Al(OH)3→Al2O3
Al2O3+3H2SO4 → Al2(SO4)3+3H2O
Al2(SO4)3+6NaOH → 2Al(OH)3+3Na2SO4
2Al(OH)3 → Al2O3+3H2O
Al2O3→Al2(SO4)3→Al(OH)3→Al2O3
Al2O3+3H2SO4 → Al2(SO4)3+3H2O
Al2(SO4)3+6NaOH → 2Al(OH)3+3Na2SO4
2Al(OH)3 → Al2O3+3H2O