Question

Al->Al2O3->AlCl3->Al(OH)3->Al2O3->Al2(SO4)3

Answer 1

1)4Al+3O2->2Al2O3
2)Al2O3+HCl->AlCl3+H2O
3)AlCl3+H2O->Al(OH)3
4)Al(OH)3->Al2O3+H2
5)Al2O3+H2SO4->Al2(SO4)3+H2