1)
Al -> Al+3 + 3e
aN+5 + 3ae -> aNO
2bN+5 + 8be -> bN2O
=> (a+2b)N+5 + (3a + 8b)e -> aNO + bN2O
(3a+8b) Al + (12a+30b) HNO3 -> (3a+8b) Al(NO3)3 + 3a NO + 3b N2O + (6a+15b) H2O
2)
Al -> Al+3 + 3e
3N+5 + 9e -> 3NO
2N+5 + 20e -> 2N2
=> 5N+5 + 29e -> 3NO + 2N2
29Al + 108HNO3 ---> 29Al(NO3)3 + 9NO + 6N2 + 54H2O