\(Na_2CO_3+2HCl\rightarrow2NaCl+H_2O+CO_2\)

a 2a a (mol)

\(CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\)

b 2b b (mol)

n\(CO_2=\dfrac{6,72}{22,4}\)=0,3(mol)

gọi số mol của Na\(_2CO_3\) trong hỗn hợp là a;\(CaCO_3\) là b ,ta có hệ phương trình:

\(\left\{{}\begin{matrix}a+b=0,3\\106a+100b=30,36\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}a=0,06\\b=0,24\end{matrix}\right.\)

\(m_{Na_2CO_3}=106.0,06=6,36\left(g\right)\)

\(\rightarrow\%m_{Na_2CO_3}=\dfrac{6,36}{30,36}.100\approx21\%\)

\(\Leftrightarrow\%m_{CaCO_3}\approx100-21=79\%\)

n\(_{HCl\left(lt\right)}\)=0,06.2+0,24.2=0,6(mol)

\(n_{HCl\left(tt\right)}=0,6.120\%=0,72\)(mol)

\(V_{HCl\left(tt\right)}=\dfrac{0,72}{2}=0,36\left(l\right)=360\left(ml\right)\)

2CH3COOH+CaCO3-to>(CH3COO)2Ca+H2O+CO2

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

2CH3COOH+CaO->(CH3COO)2Ca+H2O

0,1----------------0,05

n CO2=0,2 mol

=>%m CaCO3=\(\dfrac{0,2.100}{22,8}100=87,72\%\)

=>%m CaO=12,28%

=>n CaO=0,05 mol

=>VCH3COOH=\(\dfrac{0,5}{2}=0,25l\)

a)

\(n_{CO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

PTHH: CaCO₃ + 2CH₃COOH --> (CH₃COO)₂Ca + CO₂ + H₂O

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

=> \(m_{CaCO_3}=0,2.100=20\left(g\right)\)

=> \(\left\{{}\begin{matrix}\%m_{CaCO_3}=\dfrac{20}{22,8}=87,72\%\\\%m_{CaO}=100\%-87,72\%=12,28\%\end{matrix}\right.\)

b)

\(n_{CaO}=\dfrac{22,8-20}{56}=0,05\left(mol\right)\)

PTHH: CaO + 2CH₃COOH --> (CH₃COO)₂Ca + H₂O

            0,05---->0,1

=> \(V_{dd.CH_3COOH}=\dfrac{0,1+0,4}{2}=0,25\left(l\right)\)

c) \(\left\{{}\begin{matrix}n_{CH_3COOH}=\dfrac{a}{60}\left(mol\right)\\n_{C_2H_5OH}=\dfrac{1,5a}{46}\left(mol\right)\\n_{CH_3COOC_2H_5}=\dfrac{1,2a}{88}\left(mol\right)\end{matrix}\right.\)

PTHH: CH₃COOH + C₂H₅OH --H₂SO_4(đ),t^o--> CH₃COOC₂H₅ + H₂O

Xét tỉ lệ: \(\dfrac{\dfrac{a}{60}}{1}< \dfrac{\dfrac{1,5a}{46}}{1}\) => HIệu suất tính theo CH₃COOH

\(n_{CH_3COOH\left(pư\right)}=\dfrac{1,2a}{88}\left(mol\right)\)

=> \(H=\dfrac{\dfrac{1,2a}{88}}{\dfrac{a}{60}}.100\%=81,82\%\)

a) PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)

                \(ZnO+2HCl\rightarrow ZnCl_2+H_2O\)

b) Ta có: \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)=n_{Zn}\) \(\Rightarrow n_{ZnO}=\dfrac{20-0,1\cdot65}{81}=\dfrac{1}{6}\left(mol\right)\)

\(\Rightarrow n_{ZnCl_2}=n_{Zn}+n_{ZnO}=\dfrac{4}{15}\left(mol\right)\) 

Mặt khác: \(m_{H_2}=0,1\cdot2=0,2\left(g\right)\)

\(\Rightarrow m_{dd}=m_{hh}+m_{ddHCl}-m_{H_2}=119,8\left(g\right)\) \(\Rightarrow C\%_{ZnCl_2}=\dfrac{\dfrac{4}{15}\cdot136}{119,8}\cdot100\%\approx30,27\%\)

c) Giả sử khí là SO₂

PTHH: \(Zn+H_2SO_{4\left(đ\right)}\xrightarrow[]{t^o}ZnSO_4+SO_2\uparrow+H_2O\)

Theo PTHH: \(n_{SO_2}=n_{Zn}=0,1\left(mol\right)\) \(\Rightarrow V_{SO_2}=0,1\cdot22,4=2,24\left(l\right)\)

Giả sử: \(\left\{{}\begin{matrix}n_{Mg}=x\left(mol\right)\\n_{Al}=y\left(mol\right)\end{matrix}\right.\)

⇒ 24x + 27y = 7,8 (1)

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

BT e, có: 2x + 3y = 0,8 (2)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}x=0,1\left(mol\right)\\y=0,2\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{Mg}=0,1.24=2,4\left(g\right)\\m_{Al}=0,2.27=5,4\left(g\right)\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{2,4}{7,8}.100\%\approx30,77\%\\\%m_{Al}\approx69,23\%\end{matrix}\right.\)

b, BTNT Mg và Al, có:

n_MgCl2 = n_Mg = 0,1 (mol)

 n_AlCl3 = n_Al = 0,2 (mol)

\(\Rightarrow\left\{{}\begin{matrix}\%m_{MgCl_2}=\dfrac{0,1.95}{0,1.95+0,2.133,5}.100\%\approx26,24\%\\\%m_{AlCl_3}\approx73,76\%\end{matrix}\right.\)

Bạn tham khảo nhé!

^{trả lời nhanh cho em ạ}

\(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\\ Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ n_{Fe}=n_{H_2}=0,1\left(mol\right)\\ m_{Fe}=0,1.56=5,6\left(g\right)\\ \%m_{Fe}=\dfrac{5,6}{8}.100=70\%\\ \Rightarrow\%m_{Cu}=100\%-70\%=30\%\)

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

            \(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)  (2)

a) Ta có: \(\Sigma n_{H_2}=\dfrac{17,92}{22,4}=0,8\left(mol\right)\)

Gọi số mol của Mg là \(a\) \(\Rightarrow n_{H_2\left(1\right)}=a\)

Gọi số mol của Fe là \(b\) \(\Rightarrow n_{H_2\left(2\right)}=b\)

Ta lập được hệ phương trình:

\(\left\{{}\begin{matrix}a+b=0,8\\24a+56b=25,6\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,6\\b=0,2\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}n_{Mg}=0,6mol\\n_{Fe}=0,2mol\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{Mg}=0,6\cdot24=14,4\left(g\right)\\m_{Fe}=11,2\left(g\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{14,4}{25,6}\cdot100\%=56,25\%\\\%m_{Fe}=43,75\%\end{matrix}\right.\)

b) Theo PTHH: \(\left\{{}\begin{matrix}n_{HCl\left(1\right)}=2n_{Mg}=1,2mol\\n_{HCl\left(2\right)}=2n_{Fe}=0,4mol\end{matrix}\right.\)

\(\Rightarrow\Sigma n_{HCl}=1,6mol\) \(\Rightarrow V_{ddHCl}=\dfrac{1,6}{2}=0,8\left(l\right)=800ml\)

c) PTHH: \(MgCl_2+2NaOH\rightarrow2NaCl+Mg\left(OH\right)_2\downarrow\)

                 \(FeCl_2+2NaOH\rightarrow2NaCl+Fe\left(OH\right)_2\downarrow\)

Theo các PTHH: \(\left\{{}\begin{matrix}n_{Mg\left(OH\right)_2}=n_{MgCl_2}=n_{Mg}=0,6mol\\n_{Fe\left(OH\right)_2}=n_{FeCl_2}=n_{Fe}=0,2mol\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{Fe\left(OH\right)_2}=0,2\cdot90=18\left(g\right)\\m_{Mg\left(OH\right)_2}=0,6\cdot58=34,8\left(g\right)\end{matrix}\right.\) 

\(\Rightarrow m_{kếttủa}=18+34,8=52,8\left(g\right)\)          

PTHH: 

\(Cu+HCl--\times-->\)

\(2Ag+2HCl--->2AgCl\downarrow+H_2\)

Ta có: \(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

Theo PT: \(n_{Ag}=2.n_{H_2}=2.0,15=0,3\left(mol\right)\)

=> \(m_{Ag}=0,3.108=32,4\left(g\right)>5,9\left(g\right)\)

(Sai đề nhé.)

PTHH: 

Cu + H₂SO₄ ---x--->

Fe + H₂SO₄ ---> FeSO₄ + H₂ (1)

2Cu + O₂ ---t^o---> 2CuO (2)

Ta có: \(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

Theo PT₍₁₎: \(n_{Fe}=n_{H_2}=0,3\left(mol\right)\)

=> \(m_{Fe}=0,3.56=16,8\left(g\right)\)

Ta có: \(n_{CuO}=\dfrac{4}{80}=0,05\left(mol\right)\)

Theo PT₍₂₎: \(n_{Cu}=n_{CuO}=0,05\left(mol\right)\)

=> \(m_{Cu}=0,05.64=3,2\left(g\right)\)

=> \(\%_{m_{Cu}}=\dfrac{3,2}{3,2+16,8}.100\%=16\%\)

\(\%_{m_{Fe}}=100\%-16\%=84\%\)