nAl = 8.1/27=0.3mol
2Al + 3H2SO4 -> Al2(SO4)3 + 3H2
(mol) 0.3 0.45 0.15 0.45
a)mH2SO4 = 0.45*98=44.1g
b) mdd H2SO4 = 44.1*100/12.25=360g
mH2 = 0.45*2=0.9mol
mdd = mAl + mddH2SO4 - mH2
=8.1+360 -0.9=367.2g
mAl2(SO4)3 = 0.15*342=51.3g
C%Al2(SO4)3 = 51.3/267.2*100%=19.2%