a)
$n_{Al} = \dfrac{0,54}{27} = 0,02(mol)$
$2Al + 6HCl \to 2AlCl_3 + 3H_2$
$n_{H_2} = \dfrac{3}{2}n_{Al} = 0,03(mol)$
$V_{H_2} = 0,03.22,4 = 0,672(lít)$
b)
$n_{HCl} = 3n_{Al} = 0,06(mol)$
$C_{M_{HCl}} = \dfrac{0,06}{0,18} = 0,33M$
$C_{M_{AlCl_3}} = \dfrac{0,02}{0,18} = 0,11M$