Phần 1 : $n_{NO_2} = \dfrac{8,96}{22,4} = 0,4(mol)$
$Cu + 4HNO_{3\ đặc} \to Cu(NO_3)_2 + 2NO_2 + 2H_2O$
$n_{Cu} = \dfrac{1}{2}n_{NO_2} = 0,2(mol)$
Phần 2 : $n_{H_2} = \dfrac{6,72}{22,4} = 0,3(mol)$
$2Al + 6HCl \to 2AlCl_3 + 3H_2$
$n_{Al} = \dfrac{2}{3}n_{H_2} = 0,2(mol)$
Suy ra:
$m = (0,2.64 + 0,2.27).2 = 36,4 (gam)$