$n_{Al} = \dfrac{4,05}{27} = 0,15(mol)$
$2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2$
Theo PTHH :
$n_{H_2} = \dfrac{3}{2}n_{Al} = 0,225(mol)$
$V_{H_2} = 0,225.22,4 = 5,04(lít)$
\(n_{Al}=\dfrac{m}{M}=\dfrac{4,05}{27}=0,15\left(mol\right)\)
PTHH:\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
0,15 0,225
\(V_{H2}=n.22,4=0,225.22,4=5,04\left(l\right)\)