\(a) n_{Mg}= a(mol) ; n_{Al} = b(mol) \Rightarrow 24a + 27b =2,55(1)\\ Mg + 2HCl \to MgCl_2 + H_2\\ 2Al + 6HCl \to 2AlCl_3 + 3H_2\\ n_{H_2} = a + 1,5b = \dfrac{2,8}{22,4}=0,125(2)\\ (1)(2) \Rightarrow a = b = 0,05\\ \%m_{Mg} = \dfrac{0,05.24}{2,55}.100\% = 47,06\%\ ;\ \%m_{Al} =100\% -47,06\% = 52,94\%\\ b) n_{HCl} = 2n_{H_2} = 0,125.2 = 0,25(mol)\\ m_{dd\ HCl} = \dfrac{0,25.36,5}{7,3\%} = 125(gam)\\ V_{dd\ HCl} = \dfrac{125}{1,2} = 104,17(ml)\)

\(1)n_{H_2}=\dfrac{3,36}{22,4}=0,15(mol)\\ Mg+2HCl\to MgCl_2+H_2\\ Fe+2HCl\to FeCl_2+H_2\)

Từ giả thiết và theo PT: 

\(\begin{cases} 24n_{Mg}+56n_{Fe}=5,2\\ n_{Mg}+n_{Fe}=0,15 \end{cases}\\ \Rightarrow n_{Mg}=0,1(mol);n_{Fe}=0,05(mol)\)

\(\Rightarrow \begin{cases} \%m_{Mg}=\dfrac{0,1.24}{5,2}.100\%=46,15\%\\ \%m_{Fe}=100-46,15=53,85\% \end{cases}\\ 2)\Sigma n_{HCl}=2n_{H_2}=0,3(mol)\\ \Rightarrow V_{dd_{HCl}}=\dfrac{0,3}{1}=0,3(l)=300(ml)\)

a) Đặt \(\left\{{}\begin{matrix}n_{Mg}=a\left(mol\right)\\n_{Al}=b\left(mol\right)\end{matrix}\right.\) \(\Rightarrow24a+27b=5,1\)  (1)

Ta có: \(n_{H_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)

Bảo toàn electron: \(2a+3b=0,5\)  (2)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}a=0,1\\b=0,1\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{0,1\cdot24}{5,1}\cdot100\%\approx47,06\%\\\%m_{Al}=52,94\%\end{matrix}\right.\)

b) Bảo toàn nguyên tố: \(n_{HCl}=2n_{H_2}=0,5\left(mol\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{0,5\cdot36,5}{7,3\%}=250\left(g\right)\)

\(\Rightarrow V_{HCl}=\dfrac{250}{1,2}\approx208,33\left(ml\right)\)

\(n_{HCl}=2.0,4=0,8(mol)\\ n_{Fe}=x(mol);n_{Al}=y(mol)\\ \Rightarrow 56x+27y=11(1)\\ Fe+2HCl\to FeCl_2+H_2\\ 2Al+6HCl\to 2AlCl_3+3H_2\\ \Rightarrow 2x+3y=0,8(2)\\ (1)(2)\Rightarrow x=0,1(mol);y=0,2(mol)\)

\(a,\Sigma n_{H_2}=x+1,5y=0,4(mol)\\ \Rightarrow V_{H_2}=0,4.22,4=8,96(l)\\ b,m_{Fe}=0,1.56=5,6(g);m_{Al}=0,2.27=5,4(g)\\ c,m_{dd_{HCl}}=400.1,12=448(g)\\ n_{FeCl_2}=0,1(mol);n_{AlCl_3}=0,2(mol)\\ \Rightarrow C\%_{FeCl_2}=\dfrac{0,1.127}{5,6+448-0,1.2}.100\%=2,8\%\\ C\%_{AlCl_3}=\dfrac{0,2.133,5}{5,4+448-0,3.2}.100\%=5,9\%\)

\(a.Đặt:\left\{{}\begin{matrix}Zn:x\left(mol\right)\\Mg:y\left(mol\right)\end{matrix}\right.\\ Zn+2HCl\rightarrow ZnCl_2+H_2\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ n_{H_2}=0,3\left(mol\right)\\ Tacó:\left\{{}\begin{matrix}65x+24y=11,3\\x+y=0,3\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}x=0,1\\y=0,2\end{matrix}\right.\\ \Rightarrow m_{Zn}=0,1.65=6,5\left(g\right);m_{Mg}=0,2.24=4,8\left(g\right)\\ b.\%m_{Zn}=\dfrac{6,5}{11,3}=57,52\%;\%m_{Mg}=100-57,52=42,48\%\\ c.3H_2+Fe_2O_3-^{t^o}\rightarrow2Fe+3H_2O\\ TheoPT:n_{Fe_2O_3}=\dfrac{1}{3}n_{H_2}=0,1\left(mol\right)\\ \Rightarrow m_{Fe_2O_3}=0,1.160=16\left(g\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{Fe}=n_{H_2}=\dfrac{0,448}{22,4}=0,02\left(mol\right)\\ a,\%m_{Fe}=\dfrac{0,02.56}{4,36}.100\approx25,688\%\\ \Rightarrow\%m_{Ag}\approx74,312\%\\ b,Ta.thấy:2,18=\dfrac{1}{2}.4,36\\ \Rightarrow m_{hh\left(câuB\right)}=\dfrac{1}{2}.m_{hh\left(câuA\right)}\\ n_{Fe}=\dfrac{0,02}{2}=0,01\left(mol\right)\\ n_{Ag}=\dfrac{2,18-0,01.56}{108}=0,015\left(mol\right)\\ 2Fe+3Cl_2\rightarrow\left(t^o\right)2FeCl_3\\ 2Ag+Cl_2\rightarrow\left(t^o\right)2AgCl\\ n_{Cl_2}=\dfrac{3}{2}.n_{Fe}+\dfrac{1}{2}.n_{Ag}=\dfrac{3}{2}.0,01+\dfrac{1}{2}.0,015=0,0225\left(mol\right)\\ \Rightarrow V_{Cl_2\left(đktc\right)}=0,0225.22,4=0,504\left(l\right)\)

a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

b, Ta có: \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

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

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,1.65}{20}.100\%=32,5\%\\\%m_{Al_2O_3}=67,5\%\end{matrix}\right.\)

c, Ta có: m_Al2O3 = 20 - 0,1.65 = 13,5 (g)

\(\Rightarrow n_{Al_2O_3}=\dfrac{13,5}{102}=\dfrac{9}{68}\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Zn}+6n_{Al_2O_3}=\dfrac{169}{170}\left(mol\right)\)

\(\Rightarrow V_{ddHCl}=\dfrac{\dfrac{169}{170}}{1}\approx0,994\left(l\right)\)

d, Theo PT: \(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=0,1\left(mol\right)\\n_{AlCl_3}=2n_{Al_2O_3}=\dfrac{9}{34}\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,1.136=13,6\left(g\right)\\m_{AlCl_3}=\dfrac{9}{34}.133,5\approx35,34\left(g\right)\end{matrix}\right.\)

nH2 = 2.24/22.4 = 0.1 (mol) 

Zn + 2HCl => ZnCl2 + H2 

ZnO + 2HCl => ZnCl2 + H2O 

nZn = nH2 = 0.1 (mol) 

=> mZn = 6.5 g

mZnO = 14.6 - 6.5 = 8.1 (g) 

nZnO = 0.1 (mol)  

%Zn = 6.5/14.6 * 100% = 44.52%

%ZnO = 55.48%

nHCl = 0.1*2 + 0.1*2= 0.4 (mol) 

Vdd HCl = 0.4 / 0.5 = 0.8 l