\(n_{Al}=\dfrac{5.4}{27}=0.2\left(mol\right)\)
\(n_{H_2SO_4}=\dfrac{200\cdot39.2\%}{98}=0.8\left(mol\right)\)
\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
Lập tỉ lệ :
\(\dfrac{0.2}{2}< \dfrac{0.8}{3}\) => H2SO4 dư
\(n_{H_2}=\dfrac{3}{2}\cdot0.2=0.3\left(mol\right)\)
\(V_{H_2}=0.3\cdot22.4=6.72\left(l\right)\)
\(m_{dd}=5.4+200-0.3\cdot2=204.8\left(g\right)\)
\(m_{Al_2\left(SO_4\right)_3}=0.1\cdot342=34.2\left(g\right)\)
\(C\%_{Al_2\left(SO_4\right)_3}=\dfrac{34.2}{204.8}\cdot100\%=16.7\%\)