In the reaction,

$2\mathrm{Al}\left(s\right)+6\mathrm{HCl}\left(aq\right)⟶6{\mathrm{Cl}}^{-}\left(aq\right)+3{\mathrm{H}}_2$. 

6 L HCl(aq) is consumed for every 3 L ${\mathrm{H}}_2$ produced.

$33.6 \mathrm{L} {\mathrm{H}}_2\left(\mathrm{g}\right)$is produced regardless temperature and pressure for every moles that reacts.

$67.2 \mathrm{L} {\mathrm{H}}_2\left(\mathrm{g}\right)$ at 1 atm, 273 K is produced for every mole Al that reacts.

$11.2 \mathrm{L} {\mathrm{H}}_2\left(\mathrm{g}\right)$at 1 atm, 273 K is produced for every mole HCI(aq) consumed