\(a/ZnO+2HCl\rightarrow ZnCl_2+H_2O\\ Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\\ b/n_{HCl}=\dfrac{250.7,3}{100}:36,5=0,5mol\\ n_{ZnO}=a;n_{Fe_2O_3}=b\\ \Rightarrow\left\{{}\begin{matrix}81a+160b=16,1\\2a+6b=0,5\end{matrix}\right.\\ \Rightarrow a=b=0,1mol\\ \%m_{ZnO}=\dfrac{0,1.81}{16,1}\cdot100=50,3\%\\ \%m_{Fe_2O_3}=100-50,3=49,7\%\\ c/C_{\%ZnCl_2}=\dfrac{136.0,1}{16,1+250}\cdot100=5\%\\ C_{\%FeCl_3}=\dfrac{0,1.2.162,5}{16,1+250}=12\%\)

\(n_{CuO}=a\left(mol\right),n_{Fe_2O_3}=b\left(mol\right)\)

\(m=80a+160b=20\left(g\right)\left(1\right)\)

\(n_{HCl}=0.2\cdot3.5=0.7\left(mol\right)\)

\(CuO+2HCl\rightarrow CuCl_2+H_2O\)

\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

\(n_{HCl}=2a+6b=0.7\left(mol\right)\left(2\right)\)

\(\left(1\right),\left(2\right):a=0.05,b=0.1\)

\(m_{CuO}=0.05\cdot80=4\left(g\right)\)

\(m_{Fe_2O_3}=0.1\cdot160=16\left(g\right)\)

PTHH: \(Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)  (1)

             \(MgO+2HCl\rightarrow MgCl_2+H_2O\)  (2)

a) Ta có: \(n_{H_2}=\dfrac{22,4}{22,4}=1\left(mol\right)=n_{Mg}\) \(\Rightarrow m_{Mg}=1\cdot24=24\left(g\right)\)

\(\Rightarrow\%m_{Mg}=\dfrac{24}{32}\cdot100\%=75\%\) \(\Rightarrow\%m_{MgO}=25\%\)

b) Theo 2 PTHH: \(\left\{{}\begin{matrix}n_{HCl\left(1\right)}=2n_{Mg}=2mol\\n_{HCl\left(2\right)}=2n_{MgO}=2\cdot\dfrac{32-24}{40}=0,4mol\end{matrix}\right.\)

\(\Rightarrow\Sigma n_{HCl}=2,4mol\) \(\Rightarrow m_{ddHCl}=\dfrac{2,4\cdot36,5}{7,3\%}=1200\left(g\right)\)

c) Theo PTHH: \(\Sigma n_{MgCl_2}=\dfrac{1}{2}\Sigma n_{HCl}=1,2mol\)

\(\Rightarrow\Sigma m_{MgCl_2}=1,2\cdot95=114\left(g\right)\)

Mặt khác: \(m_{H_2}=1\cdot2=2\left(g\right)\)

\(\Rightarrow m_{dd}=m_{hh}+m_{ddHCl}-m_{H_2}=1230\left(g\right)\)

\(\Rightarrow C\%_{MgCl_2}=\dfrac{114}{1230}\cdot100\%\approx9,27\%\)

a) nH2=0,2(mol)

PTHH: Mg + 2 HCl -> MgCl2 + H2

0,2______0,4_______0,2_____0,2(mol)

PTHH: MgO +2 HCl -> MgCl2 + H2O

b) mMgO= 8,8 - 0,2.24=4(g)

%mMgO= (4/8,8).100= 45,455%

=>%Mg=54,545%

c) nHCl(tổng)= 2. nMg + 2. nMgO= 2. 0,2+ 0,1.2=0,6(mol)

=> mHCl= 0,6.36,5=21,9(g)

=>mddHCl=(21,9.100)/7,3=300(g)

d) mddMgCl2= mddHCl + m(hỗn hợp ban đầu) - mH2

<=>mddHCl= 300+ 8,8- 0,2.2= 308,4(g)

nMgCl2=0,3(mol) => mMgCl2= 0,3.95=28,5(g)

=>C%ddMgCl2= (28,5/308,4).100=9,241%

-

Fe₂O₃ + 6HCl --> 2FeCl₃ + 3H₂O

Mg + 2HCl --> MgCl₂ + H₂

- 

\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

\(n_{HCl}=\dfrac{200.18,25}{100.36,5}=1\left(mol\right)\)

PTHH: Mg + 2HCl --> MgCl₂ + H₂

          0,2<----0,4<---------------0,2

            Fe₂O₃ + 6HCl --> 2FeCl₃ + 3H₂O

            0,1<-----0,6

=> \(\left\{{}\begin{matrix}\%Mg=\dfrac{0,2.24}{0,2.24+0,1.160}.100\%=23,077\%\\\%Fe_2O_3=\dfrac{0,1.160}{0,2.24+0,1.160}.100\%=76,923\%\end{matrix}\right.\)

\(n_{MgO}=a\left(mol\right),n_{Fe_2O_3}=b\left(mol\right)\)

\(m=40a+160b=12\left(g\right)\left(1\right)\)

\(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)

\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

\(m_{Muối}=120a+400y=32\left(g\right)\left(2\right)\)

\(\left(1\right),\left(2\right):a=0.1,b=0.05\)

\(\%MgO=\dfrac{0.1\cdot40}{12}\cdot100\%=33.33\%\)

\(\%Fe_2O_3=66.67\%\)

\(m_{dd}=12+200=212\left(g\right)\)

\(C\%_{MgSO_4}=\dfrac{0.1\cdot120}{212}\cdot100\%=5.66\%\)

\(C\%_{Fe_2\left(SO_4\right)_3}=\dfrac{0.05\cdot400}{212}\cdot100\%=9.42\%\)

\(a)\\ Zn + 2HCl \to ZnCl_2 + H_2\\ 2Al + 6HCl \to 2AlCl_3 + 3H_2\)

\(b)\ n_{Zn} = a\ mol\ ;\ n_{Al} = b\ mol\\ \Rightarrow65a + 27b = 6,6(1)\\ n_{H_2} = a + 1,5b = \dfrac{4,704}{22,4} = 0,21(2)\\ (1)(2)\Rightarrow a = 0,06 ; b = 0,1\\ \Rightarrow m_{Zn} = 0,06.65 = 3,9\ gam\ ;\ m_{Al} = 0,1.27 = 2,7\ gam\)

\(n_{Zn}=a\left(mol\right),n_{Al}=b\left(mol\right)\)

\(m_X=65a+27b=6.6\left(g\right)\left(1\right)\)

\(n_{H_2}=\dfrac{4.704}{22.4}=0.21\left(mol\right)\)

\(Zn+2HCl\rightarrow ZnCl_2+H_2\)

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

\(\Rightarrow a+1.5b=0.21\left(2\right)\)

\(\left(1\right),\left(2\right):\)

\(a=0.06\)

\(b=0.1\)

\(m_{Zn}=0.06\cdot65=3.9\left(g\right)\)

\(m_{Al}=0.1\cdot27=2.7\left(g\right)\)