\(n_{Al}=\dfrac{31,6}{27}=\dfrac{158}{135}\left(mol\right)\)
PT : \(2Al+6H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
\(\dfrac{158}{135}\)---->\(\dfrac{316}{45}\)--------->\(\dfrac{158}{135}\)---->\(\dfrac{158}{45}\)
a) \(m_{ddH2SO4}=\dfrac{\dfrac{316}{45}.98}{19,6\%}=3511,1\left(g\right)\)
b) \(V_{H2\left(đktc\right)}=\dfrac{158}{45}.22,4=78,65\left(l\right)\)
\(C\%_{Al2\left(SO4\right)3}=\dfrac{\dfrac{158}{135}.342}{31,6+3511,1-\dfrac{158}{45}.2}.100\%=11,32\%\)