\(a,\) Đặt \(\begin{cases} n_{Fe}=x(mol)\\ n_{Al}=y(mol) \end{cases}\Rightarrow 56x+27y=22(1)\)

\(n_{H_2}=\dfrac{17,92}{22,4}=0,8(mol)\\ PTHH:Fe+2HCl\to FeCl_2+H_2\\ 2Al+6HCl\to 2AlCl_3+3H_2\\ \Rightarrow x+1,5y=0,8(2)\\ (1)(2)\Rightarrow \begin{cases} x=0,2(mol)\\ y=0,4(mol) \end{cases} \Rightarrow \begin{cases} \%_{Fe}=\dfrac{0,2.56}{22}.100\%=50,91\%\\ \%_{Al}=100\%-50,91\%=49,09\% \end{cases} \)

\(b,\Sigma n_{HCl}=2n_{Fe}+3n_{Al}=0,4+1,2=1,6(mol)\\ \Rightarrow m_{dd_{HCl}}=\dfrac{1,6.36,5}{3,7\%}=1578,38\%\)

a, Ta có: 27n_Al + 56n_Fe = 0,83 (1)

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

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

Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Al}+n_{Fe}=\dfrac{0,56}{22,4}=0,025\left(mol\right)\left(2\right)\)

Từ (1) và (2) \(\Rightarrow n_{Al}=n_{Fe}=0,01\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Al}=\dfrac{0,01.27}{0,83}.100\%\approx32,53\%\\\%m_{Fe}\approx67,47\%\end{matrix}\right.\)

b, n_H2SO4 = n_H2 = 0,025 (mol)

\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,025.98}{20\%}=12,25\left(g\right)\)

2Al+6Hcl->2AlCl₃+3H₂

x-----------------x--------3\2x

Fe+2HCl->FeCl₂+H₂

y-----------------y------y 

Ta có :

\(\left\{{}\begin{matrix}27x+56y=9,65\\\dfrac{3}{2}x+y=0,325\end{matrix}\right.\)

=>x=0,15 mol, y=0,1 mol

=>m Al=0,15.27=4,05g

=>m Fe=56.0,1=5,6g

b)

=>m AlCl3=0,15.133,5=20,025g

=>m FeCl2=0,1.127=12,7g

\(\left\{{}\begin{matrix}Al\\Fe\end{matrix}\right.+HCl->\left\{{}\begin{matrix}AlCl3\\FeCl2\end{matrix}\right.+7,28lH2\)

a, 

Ta có :

\(\left\{{}\begin{matrix}27x+56y=9,65\\3x+2y=0,65\left(bt-e\right)\end{matrix}\right.\)

\(\left\{{}\begin{matrix}x=0,15\left(mol\right)\\y=0,1\left(mol\right)\end{matrix}\right.\)

\(\left\{{}\begin{matrix}mAl=0,15.27=4,05\left(g\right)\\mFe=0,1.56=5,6\left(g\right)\end{matrix}\right.\)

b,

Bảo toàn nguyên tố :

nAl = nAlCl3 = 0,15 ( mol )

nFe = nFeCl2 = 0,1 ( mol )

Khối lượng chất tan A :

m = 0,15 . 133,5 + 0,1 . 127 = 32,725(g)

\(a.BTNT\left(H\right):n_{HCl}=2n_{H_2}=0,65\left(mol\right)\\ \Rightarrow CM_{HCl}=\dfrac{0,65}{0,5}=1,3M\\ b.2Al+6HCl\rightarrow2AlCl_3+3H_2\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ Đặt:\left\{{}\begin{matrix}n_{Al}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}\dfrac{3}{2}x+y=0,325\\27x+56y=9,65\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x=0,15\\y=0,1\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}m_{Al}=4,05\left(g\right)\\m_{Fe}=5,6\left(g\right)\end{matrix}\right.\)

a)

\(n_{H_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)

PTHH: Fe + H₂SO₄ --> FeSO₄ + H₂

             0,4<--0,4<--------------0,4

=> m_Fe = 0,4.56 = 22,4 (g)

\(\%m_{Fe}=\dfrac{22,4}{28,8}.100\%=77,78\%\Rightarrow\%m_{Cu}=100\%-77,78\%=22,22\%\)

b) \(m_{H_2SO_4}=0,4.98=39,2\left(g\right)\Rightarrow m_{dd.H_2SO_4}=\dfrac{39,2.100}{17}=\dfrac{3920}{17}\left(g\right)\)

Đặt : 

nAl = a (mol) 

nFe = b(mol) 

mX = 27a + 56b = 16.6 (g) (1) 

2Al + 3H2SO4 => Al2(SO4)3 + 3H2 

Fe + H2SO4 => FeSO4 + H2 

mM = 342a  + 152b = 64.6 (g) (2) 

(1) , (2):

a = 4/55

b = 23/88

%Al = (4/55*27) / 16.6 *100% = 11.83%

%Fe = 100 - 11.83 = 88.17%

nH2 = 3/2a + b = 3/2 * 4/55 + 23/88 = 163/440 (mol) 

VH2 = 8.3 (l)

Câu 1: 

\(n_{H_2}=\dfrac{2.91362}{22.4}=0.13mol\)

\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)

 a           a                a           a

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

 2b          3b               b                 3b

Ta có: \(\left\{{}\begin{matrix}24a+54b=2.58\\a+3b=0.13\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0.04\\b=0.03\end{matrix}\right.\)

\(m_{Mg}=0.04\times24=0.96g\)

\(m_{Al}=0.03\times2\times27=1.62g\)

\(V_{H_2SO_4}=\dfrac{0.04+3\times0.03}{0.5}=0.26l\)

Câu 2:

\(n_{H_2}=\dfrac{3.136}{22.4}=0.14mol\)

\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)

a            a              a             a

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

b           b                 b         b

Ta có: \(\left\{{}\begin{matrix}24a+56b=4.96\\a+b=0.14\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}a=0.09\\b=0.05\end{matrix}\right.\)

\(m_{Mg}=0.09\times24=2.16g\)

\(m_{Fe}=0.05\times56=2.8g\)

\(C\%_{H_2SO_4}=\dfrac{0.14\times98\times100}{200}=6.86\%\)

Câu 3: 

\(n_{H_2}=\dfrac{1.568}{22.4}=0.07mol\)

\(Ba+H_2SO_4\rightarrow BaSO_4+H_2\)

a           a              a             a

\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)

b          b                 b             b

Ta có: \(\left\{{}\begin{matrix}137a+24b=3.94\\a+b=0.07\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}a=0.02\\b=0.05\end{matrix}\right.\)

\(m_{Ba}=0.02\times137=2.74g\)

\(m_{Mg}=0.05\times24=1.2g\)

\(CM_{H_2SO_4}=\dfrac{0.07}{0.1}=0.7M\)