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![](https://rs.olm.vn/images/avt/0.png?1311)
a) PTHH: \(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)
a_____2a______a_____a (mol)
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
b_____3b_______b_____\(\dfrac{3}{2}\)b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}56a+27b=36,1\\a+\dfrac{3}{2}b=\dfrac{21,28}{22,4}=0,95\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,5\\b=0,3\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Fe}=0,5\cdot56=28\left(g\right)\\m_{Al}=8,1\left(g\right)\end{matrix}\right.\)
b+c) Theo các PTHH: \(\left\{{}\begin{matrix}n_{HCl}=2a+3b=1,9\left(mol\right)\\n_{FeCl_2}=0,5\left(mol\right)\\n_{AlCl_3}=0,3\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}C_{M_{HCl}}=\dfrac{1,9}{0,2}=9,5\left(M\right)\\C_{M_{FeCl_2}}=\dfrac{0,5}{0,2}=2,5\left(M\right)\\C_{M_{AlCl_3}}=\dfrac{0,3}{0,2}=1,5\left(M\right)\end{matrix}\right.\)
![](https://rs.olm.vn/images/avt/0.png?1311)
PTHH: \(CaO+2HCl\rightarrow CaCl_2+H_2O\) (1)
\(CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\uparrow\) (2)
a) Ta có: \(n_{CO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)=n_{CaCO_3}\)
\(\Rightarrow m_{CaCO_3}=0,2\cdot100=20\left(g\right)\) \(\Rightarrow\%m_{CaCO_3}=\dfrac{20}{25,6}\cdot100\%=78,125\%\)
\(\Rightarrow\%m_{CaO}=21,875\%\)
b) Theo 2 PTHH: \(\left\{{}\begin{matrix}n_{HCl\left(2\right)}=2n_{CaCO_3}=0,4mol\\n_{HCl\left(1\right)}=2n_{CaO}=2\cdot\dfrac{25,6-20}{56}=0,2mol\end{matrix}\right.\)
\(\Rightarrow\Sigma n_{HCl}=0,6mol\) \(\Rightarrow C\%_{HCl}=\dfrac{0,6\cdot36,5}{210\cdot1,05}\cdot100\%\approx9,93\%\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Mg + 2HCl → MgCl2 + H2 (1)
Al2O3 + 6HCl → 2AlCl3 + 3H2O (2)
nH2 = 2,8/22,4 = 0,125 mol
Theo tỉ lệ phản ứng (1) => nMg = nH2 = 0,125 mol
<=> mMg = 0,125 .24 = 3 gam và mAl2O3 = 8,1 - 3 =5,1 gam
%mMg = \(\dfrac{3}{8,1}\).100% = 37,03% => %mAl2O3 = 100 - 37,03 = 62,97%
b) nAl2O3 = \(\dfrac{5,1}{102}\)= 0,05 mol
=> nHCl pư = 2nMg + 6nAl2O3 = 0,55 mol
mHCl = 0,55.36,5 = 20,075 gam
=> mdung dịch HCl 18% = \(\dfrac{20,075}{18\%}\)= 111,53 gam
![](https://rs.olm.vn/images/avt/0.png?1311)
a, Ta có: 27nAl + 56nFe = 22 (1)
PT: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Al}+n_{Fe}=\dfrac{19,832}{24,79}=0,8\left(mol\right)\left(2\right)\)
Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}m_{Al}=0,4\left(mol\right)\\n_{Fe}=0,2\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Al}=\dfrac{0,4.27}{22}.100\%\approx49,09\%\\\%m_{Fe}\approx50,91\%\end{matrix}\right.\)
b, \(n_{HCl}=2n_{H_2}=1,6\left(mol\right)\)
\(\Rightarrow C_{M_{HCl}}=\dfrac{1,6}{0,5}=3,2\left(M\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Sửa đề: Sau phản ứng thu đc \(2240(cm^3)\) lít khí (đktc)
\(n_{H_2}=\dfrac{2,24}{22,4}=0,1(mol)\\ a,PTHH:Zn+2HCl\to ZnCl_2+H_2\\ ZnO+2HCl\to ZnCl_2+H_2O\\ b,n_{Zn}=n_{H_2}=0,1(mol)\\ \Rightarrow m_{Zn}=0,1.65=6,5(g)\\ \Rightarrow \%_{Zn}=\dfrac{6,5}{14,6}.100\%= 44,52\%\\ \Rightarrow \%_{ZnO}=100\%-44,52\%=55,48\%\\ n_{ZnO}=\dfrac{14,6-6,5}{81}=0,1(mol)\\ \Sigma n_{ZnCl_2}=n_{Zn}+n_{ZnO}=0,1+0,1=0,2(mol)\\ \Rightarrow C_{M_{ZnCl_2}}=\dfrac{0,2}{0,2}=1M\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Hòa tan hoàn toàn 12,4g hỗn hợp MgSO3 và MgO bằng lượng vừa đủ với dung dịch HCL 7,3% sau phản ứng thu được 2,479l khí đktc
a) Tính khối lượng mỗi chất trong hỗn hợp ban đầu ?
b) Tinh khối lượng dd HCL đủ dùng cho phản ứng?
c) Tính nồng độ phần trăm của muối sau phản ứng?
![](https://rs.olm.vn/images/avt/0.png?1311)
$a\big)$
$Zn+2CH_3COOH\to (CH_3COO)_2Zn+H_2$
$ZnO+2CH_3COOH\to (CH_2COO)_2Zn+H_2O$
Theo PT: $n_{Zn}=n_{H_2}=\frac{4,48}{22,4}=0,2(mol)$
$\to \%m_{Zn}=\frac{0,2.65}{21,1}.100\%\approx 61,61\%$
$\to \%m_{ZnO}=100-61,61=38,39\%$
$b\big)$
$n_{ZnO}=\frac{21,1-0,2.65}{81}=0,1(mol)$
Theo PT: $\sum n_{CH_3COOH}=2n_{Zn}+2n_{ZnO}=0,6(mol)$
$\to C_{M_{CH_3COOH}}=\dfrac{0,6}{\frac{200}{1000}}=3M$
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2mol\)
\(Zn+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Zn+H_2\)
0,2 0,2 ( mol )
\(m_{Zn}=0,2.65=13g\)
\(\%m_{Zn}=\dfrac{13}{21,1}.100=61,61\%\)
\(\%m_{ZnO}=100\%-61,61\%=38,39\%\)
\(Zn+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Zn+H_2\)
0,2 0,4 ( mol )
\(n_{ZnO}=\dfrac{21,1-13}{81}=0,1mol\)
\(ZnO+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Zn+H_2O\)
0,1 0,2 ( mol )
\(C_{M\left(CH_3COOH\right)}=\dfrac{0,4+0,2}{0,2}=3M\)