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![](https://rs.olm.vn/images/avt/0.png?1311)
\(CO_2+CaO\rightarrow CaCO_3\\ n_{CaCO_3}=n_{CO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ m_{muối}=m_{CaCO_3}=0,2.100=20\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{Mg}=\dfrac{7,2}{24}=0,3\left(mol\right)\\ n_{Cl_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ Mg+Cl_2\rightarrow\left(t^o\right)MgCl_2\\ a,Vì:\dfrac{0,2}{1}< \dfrac{0,3}{1}\Rightarrow Mgdư\\n_{Mg\left(p.ứ\right)}=n_{MgCl_2}=n_{Cl_2}=0,2\left(mol\right)\\ \Rightarrow n_{Mg\left(dư\right)}=0,3-0,2=0,1\left(mol\right)\\ m_{Mg\left(dư\right)}=0,1.24=2,4\left(g\right)\\ b,m_{MgCl_2}=0,2.95=19\left(g\right)\)
\(n_{Mg}=\dfrac{m}{M}=\dfrac{7,2}{24}=0,3\) (mol)
\(n_{Cl_2}=\dfrac{V}{22,4}=\dfrac{4,48}{22,4}=0,2\)(mol)
PTHH : Mg + Cl2 ---> MgCl2
1 : 1 : 1
Dễ thấy : \(\dfrac{n_{Mg}}{1}>\dfrac{n_{Cl_2}}{1}\)
=> Mg dư 0,1 mol
=> \(m_{Mg}=n.M=0,1.24=2,4\left(g\right)\)
=> \(n_{MgCl_2}=0,2\left(mol\right)\) => \(m_{MgCl_2}=n.M=0,2.\left(24+71\right)=19\left(g\right)\)
\(n_{Mg}=\dfrac{m}{M}=\dfrac{7,2}{24}=0,3\) (mol)
\(n_{Cl_2}=\dfrac{V}{22,4}=\dfrac{4,48}{22,4}=0,2\)(mol)
PTHH : Mg + Cl2 ---> MgCl2
1 : 1 : 1
Dễ thấy : \(\dfrac{n_{Mg}}{1}>\dfrac{n_{Cl_2}}{1}\)
=> Mg dư 0,1 mol
=> \(m_{Mg}=n.M=0,1.24=2,4\left(g\right)\)
=> \(n_{MgCl_2}=0,2\left(mol\right)\) => \(m_{MgCl_2}=n.M=0,2.\left(24+71\right)=19\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{CO2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
Pt : \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O|\)
1 2 1 1
0,2 0,2
\(n_{Na2CO3}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)
⇒ \(m_{Na2CO3}=0,2.106=21,2\left(g\right)\)
⇒ Chọn câu : D
Chúc bạn học tốt
Chọn D
n CO2 = n Na2CO3 = 0,2 ( mol )
=> m Na2CO3 = 21,2 ( g )
![](https://rs.olm.vn/images/avt/0.png?1311)
\(Na_2CO_3+2HCl\rightarrow2NaCl+H_2O+CO_2\)
\(x\) 2x 2x x x
\(NaHCO_3+HCl\rightarrow NaCl+H_2O+CO_2\)
\(y\) y y y y
Ta có hệ:
\(\left\{{}\begin{matrix}106x+84y=19\\x+y=\dfrac{4,48}{22,4}\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,1\\y=0,1\end{matrix}\right.\)
\(m_{Na_2CO_3}=0,1\cdot106=10,6g\)
\(m_{NaHCO_3}=0,1\cdot84=8,4g\)
\(Na_2CO_3+2HCl\rightarrow2NaCl+CO_2+H_2O\\ NaHCO_3+HCl\rightarrow NaCl+CO_2+H_2O\\ Đặt:n_{Na_2CO_3}=a\left(mol\right);n_{NaHCO_3}=b\left(mol\right)\left(a,b>0\right)\\ m_{hh.muối.ban.đầu}=19\left(g\right)\\ \Leftrightarrow106a+84b=19\left(1\right)\\ Mặt.khác:V_{CO_2\left(tổng\right)}=22,4a+22,4b=4,48\left(2\right)\\ \left(1\right),\left(2\right)\Rightarrow\left\{{}\begin{matrix}106a+84b=19\\22,4a+22,4b=4,48\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,1\\b=0,1\end{matrix}\right.\\ \Rightarrow m_{NaHCO_3}=84.0,1=8,4\left(g\right)\\ m_{Na_2CO_3}=106.0,1=10,6\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(a,n_{Na}=\dfrac{m_{Na}}{M_{Na}}=\dfrac{4,6}{23}=0,2\left(mol\right)\\ n_{Cl_2}=\dfrac{V_{Cl_2\left(đktc\right)}}{22,4}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ PTHH:2Na+Cl_2\rightarrow2NaCl\\ Vì:\dfrac{0,2}{2}< \dfrac{0,2}{1}\Rightarrow Cl_2dư\\ \Rightarrow n_{Cl_2\left(dư\right)}=0,2-\dfrac{0,2}{2}=0,1\left(mol\right)\\ \Rightarrow m_{Cl_2\left(dư\right)}=0,1.71=7,1\left(g\right)\\ b,n_{NaCl}=n_{Na}=0,2\left(mol\right)\\ \Rightarrow m_{NaCl}=58,5.0,2=11,7\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
PTHH: Zn + 2HCl ---> ZnCl2 + H2
0,2<--0,4<------0,2<-----0,2
=> \(\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,2.65}{21,1}.100\%=61,61\%\\\%m_{ZnO}=100\%-61,61\%=38,39\%\end{matrix}\right.\)
\(n_{ZnO}=\dfrac{21,1-0,2.65}{81}=0,1\left(mol\right)\)
PTHH: ZnO + 2HCl ---> ZnCl2 + H2O
0,1---->0,2------>0,1
=> \(C\%_{HCl}=\dfrac{\left(0,2+0,4\right).36,5}{200}.100\%=10,95\%\)
\(m_{mu\text{ố}i}=m_{ZnCl_2}=\left(0,1+0,2\right).136=40,8\left(g\right)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2mol\)
\(n_{O_2}=\dfrac{4,48}{22,4}=0,2mol\)
\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)
\(\dfrac{0,2}{2}\) < \(\dfrac{0,2}{1}\) ( mol )
0,2 0,2 ( mol )
\(m_{H_2O}=0,2.18=3,6g\)
=> Chọn B
20 gam.