To work out how many litres of sulfuric acid we need, we have to first work out the moles of sulfuric acid we have reacting in our equation.

#1.# Write a balanced equation:

(aluminium #+# sulfuric acid #rarr# aluminium sulfate + hydrogen)

#2"Al" + 3"H"_2"SO"_4 rarr "Al"_2("SO"_4)_3 + 3"H"_2#

#2.# Work out the moles of one reagent and use the molar ratio to work out the moles of the other:

moles of #"Al"# = #("mass")/"A"_"r"= 12.7/27.0 = 0.470#

molar ratio of #"Al":"H"_2"SO"_4# = #2:3#; #therefore#

moles of #"H"_2"SO"_4 = 0.470*(3/2) = 0.705#

#3.# Solve for the unknown:

We know that #"M" = "m"/"L"#, so we can now solve for #"L"#:

#6.00=0.705/"L"#

#"6.00 L"=0.705#

#"L"=0.705/6.00 = 0.118#