Write the reaction equation: Al2 (SO4) 3⇒AlCl3⇒Al (OH) 3⇒Al2O3⇒AlBr3

1) Al2 (SO4) 3 + 3BaCl2 = 2AlCl3 + 3BaSO4 (when aluminum sulfate interacts with barium chloride, aluminum chloride and barium sulfate are formed);

2) AlCl3 + 3KOH = Al (OH) 3 + 3KCl (when aluminum chloride interacts with potassium hydroxide, aluminum hydroxide and potassium chloride are formed);

3) 2Al (OH) 3 = Al2O3 + 3H2O (when heated, aluminum hydroxide decomposes into aluminum oxide and water);

4) Al2O3 + 6HBr = 2AlBr3 + 3H2O (when aluminum oxide interacts with hydrogen bromide, aluminum bromide and water are formed).