Question

Na2O->NaOH->Al(OH)3->Al2O3->Al2(So4)3->BaSo4

Answer 1

Na2O + H2O = 2NaOH
3NaOH + AlBr3 = 3NaBr + Al(OH)3
2Al(OH)3 = Al2O3 + 3H2O
Al2O3 + 3H2SO4 = Al2(SO4)3 + 3H2O
Al2(SO4)3 + 3Ba(OH)2 = 2Al(OH)3 + 3BaSO4