Write the reaction equations: Al – Al2O3 – Al2 (SO4) 3 – Al (OH) 3 – AlCl3 – Al

1) 4Al + 3O2 = 2Al2O3 (when aluminum interacts with oxygen, aluminum oxide is formed);

2) Al2O3 + 3H2SO4 = Al2 (SO4) 3 + 3H2O (when aluminum oxide interacts with sulfuric acid, aluminum sulfate and water are formed);

3) Al2 (SO4) 3 + 6NaOH = 2Al (OH) 3 + 3Na2SO4 (when aluminum sulfate reacts with sodium hydroxide, aluminum hydroxide and sodium sulfate are formed);

4) Al (OH) 3 + 3HCl = AlCl3 + 3H2O (when aluminum hydroxide interacts with hydrochloric acid, aluminum chloride and water are formed);

5) 2AlCl3 = 2Al + 3Cl2 (when aluminum chloride decomposes, aluminum and chlorine are formed).