what is the pressure of H2 if the hydrogen gas collected occupies 14L at 300K and was produced upon reaction of 4.5 mol of Al?

Answer 1

PV=nRT

now to n...
2Al+3H2SO4>> Al2(SO4)3 + 3H2
which would indicate 4.5*3/2 moles H2

But what if the acid were HCl?
2Al+ 6HCl>>2AlCl3 + 3H2
moles of H2: 4*3/2 again.