the limiting reagent is nitrogen gas.
steps:
write out balanced equation: 3H2 + N2 = 2NH3
convert to moles to find how much NH3 each yields
find molar mass of each
10 g H2 (1 mol/2.016g) (2NH3/3H2) = 3.31 mol NH3
26g N2 (1mol/28.02g)(2NH3/1N2)=1.86 mol NH3
since N2 yields less NH3, it is the limiting reagent.
