Al2O3 ->AlCl3->Al(OH)3->Al2O3->Al2(SO4)3
1)Al2O3+6HCl=2AlCl3+3H2O
2)AlCl3+3RbOH=3RbCl+Al(OH)3
3)2Al(OH)3=Al2O3+3H2O
4)Al2O3+3SO3=Al2(SO4)3
Al2O3 ->AlCl3->Al(OH)3->Al2O3->Al2(SO4)3
1)Al2O3+6HCl=2AlCl3+3H2O
2)AlCl3+3RbOH=3RbCl+Al(OH)3
3)2Al(OH)3=Al2O3+3H2O
4)Al2O3+3SO3=Al2(SO4)3