2Al + 3H2SO4 \(\rightarrow\)Al2(SO4)3 + 3H2
nAl=\(\dfrac{8,1}{27}=0,3\left(mol\right)\)
Theo PTHH ta có:
\(\dfrac{3}{2}\)nAl=nH2=0,45(mol)
VH2=0,45.22,4=10,08(lít)
\(\dfrac{1}{2}\)nAl=nAl2(SO4)3=0,15(mol)
mAl2(SO4)3=342.0,15=51,3(g)
C% dd Al2(SO4)3=\(\dfrac{51,3}{8,1+200-0,45.2}.100\%=24,75\%\)