Question

AL+O2→AL2O3+HNO3→AL(NO3)3→AL (OH) 3→AL2O3

Answer 1

4Al + 3O2 -> 2Al2O3
Al2O3 + 6HNO3 -> 2Al(NO3)3 + 3H2O
Al(NO3)3 + 3NaOH -> Al(OH)3↓ + 3NaNO3
2Al(OH)3 -> Al2O3 + 3H2O