Al2(SO4)3⇒AlCl3⇒Al(OH)3⇒Al2O3⇒AlBr3

Al2(SO4)3 + 3 BaCl2 = 2AlCl3 + 3BaSO4↓ AlCl3 + 3NaOH = Al(OH)3 + 3NaCl 2Al(OH)3 = Al2O3 + 3H2O Al2O3 + 6HBr = 2AlBr3 + 3H2O

2Al(OH)3 + 3H2SO4 = Al2(SO4)3 + 6H2O Al2(SO4)3 + 3BaCl2 = 2AlCl3 + 3BaSO4 AlCl3 + 3NaOH = Al(OH)3 + 3NaCl  2Al(OH)3 = Al2O3 + 3H2O  последнее не знаю