nAl = 5.4/27 = 0.2 mol 

2Al + 3H2SO4 => Al2(SO4)3 + 3H2 

0.2______________0.1________0.3 

VH2 = 0.3*22.4 = 6.72 (l) 

mAl2(SO4)3 = 0.1*342 = 34.2 g 

Ta có: \(n_{H_2}=\dfrac{74,37}{24,79}=3\left(mol\right)\)

PT: \(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

a, \(n_{Al}=\dfrac{2}{3}n_{H_2}=2\left(mol\right)\)

\(\Rightarrow m_{Al}=2.27=54\left(g\right)\)

b, \(n_{H_2SO_4}=n_{H_2}=3\left(mol\right)\)

\(\Rightarrow m_{H_2SO_4}=3.98=294\left(g\right)\)

a, \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

b, \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Al}=0,3\left(mol\right)\Rightarrow V_{H_2}=0,3.22,4=6,72\left(l\right)\)

c, \(n_{AlCl_3}=n_{Al}=0,2\left(mol\right)\Rightarrow m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\)

\(n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\)

\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

\(0,3->0,3-->0,3->0,3\)

\(mH_2SO_4=0,3.98=29,4\left(g\right)\)

\(\Rightarrow C\%_{ddH_2SO_4}=\dfrac{29,4.100}{200}=14,7\%\)

\(V_{FeSO_4}=\dfrac{n}{CM}=\dfrac{0,3}{2}=0,25\left(l\right)\)

\(VH_2=0,3.22,4=6,72\left(l\right)\)

\(n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\\ pthh:Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
          0,3        0,3          0,3           0,3 
\(C\%_{H_2SO_4}=\dfrac{0,3.98}{200}.100\%=14,7\%\\ V_{FeSO_4}=\dfrac{0,3}{2}=0,15\left(l\right)\\ V_{H_2}=0,3.22,4=6,72\left(l\right)\)

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

\(n_{Al}=\dfrac{3,375}{27}=0,125\)

\(\Rightarrow n_{H_2}=\dfrac{0,125}{2}.3=0,1875mol\)      \(\Rightarrow V_{H_2}=0,1875.22,4=4,2l\)

\(n_{AlCl_3}=n_{Al}=0,125mol\)       \(\Rightarrow m_{AlCl_3}=0,125.133,5=16,6875g\)

Ta có: \(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)

PT: \(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

Theo PT: \(n_{H_2SO_4}=n_{FeSO_4}=n_{H_2}=n_{Fe}=0,1\left(mol\right)\)

a, \(V_{H_2}=0,1.24,79=2,479\left(l\right)\)

b, \(m_{H_2SO_4}=0,1.98=9,8\left(g\right)\)

\(\Rightarrow m_{ddH_2SO_4}=\dfrac{9,8}{9,8\%}=100\left(g\right)\)

c, Ta có: m _{dd sau pư} = 5,6 + 100 - 0,1.2 = 105,4 (g)

\(\Rightarrow C\%_{FeSO_4}=\dfrac{0,1.152}{105,4}.100\%\approx14,42\%\)