a) PTHH: \(Ca+H_2SO_4\rightarrow CaSO_4+H_2\uparrow\)

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

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

b) Ta có: \(\Sigma n_{H_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)

Theo các PTHH, ta thấy \(n_{H_2SO_4}=n_{H_2}=0,5\left(mol\right)\)

\(\Rightarrow m_{H_2SO_4}=0,5\cdot98=49\left(g\right)\)

Mặt khác: \(m_{H_2}=0,5\cdot2=1\left(g\right)\)

Bảo toàn khối lượng: \(m_{hh}=m_{muối}+m_{H_2}-m_{H_2SO_4}=68+1-49=20\left(g\right)\)

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 

\(\text{Em sửa 7,1 thành 8,1g nha}\\ a/ 2Al+3H_2SO_4 \rightarrow Al_2(SO_4)_3+3H_2\\ b/ \\ n_{Al}=0,3mol\\ n_{H_2SO_4}=\frac{3}{2}n_{Al}=\frac{3}{2}.0,3=0,45mol V_{H_2SO_4}=\frac{0,45}{0,05}=9M\\ c/ \\ V_{H_2}=0,45.22,4=10,08l\)

a)\(n_{Al}=\dfrac{7,1}{27}\approx0,26\left(mol\right)\)

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

          0,26----->0,39-------->0,13------->0,39 (mol)

b)\(V_{H_2SO_4}=0,39\cdot22,4=8,736\left(l\right)\)

c)\(V_{H_2}=0,39\cdot22,4=8,736\left(l\right)\)

\(a.2Al+3H2SO4\rightarrow Al2\left(SO4\right)3+3H2\)

b)\(n_{Al}=\dfrac{7,1}{27}=\dfrac{71}{270}\left(mol\right)\)

\(n_{H2SO4}=\dfrac{3}{2}n_{Al}=\dfrac{71}{180}\left(mol\right)\)

\(\Rightarrow V=\dfrac{71}{180}:0,05=\dfrac{71}{9}\left(l\right)\)

c)\(n_{H2}=\dfrac{3}{2}n_{Al}=\dfrac{71}{180}\left(mol\right)\)

\(V_{H2}=\dfrac{71}{180}.22,4=\dfrac{476}{225}\left(l\right)\)

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

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

0,2                            0,1                0,3  ( mol )

\(m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2g\)

\(V_{H_2}=0,3.22,4=6,72l\)

\(n_{H_2SO_4}=0,2.2=0,4\left(mol\right)\)

Fe + H2SO4 → FeSO4 + H2 

2Al + 3H2SO4 → Al2(SO4)3 + 3H2

Gọi x,y lần lượt là số mol Fe, Al

\(\left\{{}\begin{matrix}56x+27y=11\\x+\dfrac{3}{2}y=0,4\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=0,1\\y=0,2\end{matrix}\right.\)

=>\(\%m_{Fe}=\dfrac{0,1.56}{11}.100=50,91\%\)

=> %m _Al = 100 - 50,91 =49,09 %

b)Theo PT:  \(n_{H_2}=n_{H_2SO_4}=0,4\left(mol\right)\)

=> \(V_{H_2}=0,4.22,4=8,96\left(l\right)\)

c) \(CM_{FeSO_4}=\dfrac{0,1}{0,2}=0,5M\)

\(CM_{Al_2\left(SO_4\right)_3}=\dfrac{\dfrac{0,2}{2}}{0,2}=0,5M\)

\(a)n_{H_2}=\dfrac{14,874}{24,79}=0,6mol\\2 Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

0,4mol     0,6mol          0,2mol           0,6mol

\(m_{Al}=0,4.27=10,8g\\ b)m_{Al_2\left(SO_4\right)_3}=0,2.342=68,4g\\ c)m_{H_2SO_4}=0,6.98=58,8g\)