C2H4 + Br2 -> C2H4Br2

  a          a            a

C2H2 + 2Br2 -> C2H2Br4

   b          2b             b

n hỗn hợp khí = \(\dfrac{7.84}{22.4}=0.35mol\)

Ta có: \(\left\{{}\begin{matrix}a+b=0.35\\160a+320b=72\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0.25mol\\b=0.1mol\end{matrix}\right.\)

\(\%VC2H4=\dfrac{0.25\times22.4\times100}{7.84}=71.43\%\)

%VC2H2 = 100 - 71.43 = 28.57%

C2H4 + Br2 -> C2H4Br2

  a          a            a

C2H2 + 2Br2 -> C2H2Br4

   b          2b             b

n hỗn hợp khí = 

Ta có: 

%VC2H2 = 100 - 71.43 = 28.57%

\(n_{Br_2}=\dfrac{4}{160}=0,025\left(mol\right);n_{hh}=\dfrac{2,8}{22,4}=0,125\left(mol\right)\)

PTHH: \(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

            0,025<-0,125

\(\Rightarrow\left\{{}\begin{matrix}\%V_{C_2H_4}=\dfrac{0,025}{0,125}.100\%=20\%\\\%V_{CH_4}=100\%-20\%=80\%\end{matrix}\right.\)

PTHH: \(CH_4+2O_2\xrightarrow[]{t^o}CO_2+2H_2O\)

Ta có: \(n_{CO_2}=\dfrac{1,68}{22,4}=0,075\left(mol\right)=n_{CH_4}\)

Đặt \(\left\{{}\begin{matrix}n_{C_2H_4}=a\left(mol\right)\\n_{C_2H_2}=b\left(mol\right)\end{matrix}\right.\) \(\Rightarrow a+b=\dfrac{5,04}{22,4}-0,075=0,15\)  (1)

PTHH: \(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

            \(C_2H_2+2Br_2\rightarrow C_2H_2Br_4\)

Theo PTHH: \(28a+26b=4,1\)  (2)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}a=n_{C_2H_4}=0,1\left(mol\right)\\b=n_{C_2H_2}=0,05\left(mol\right)\end{matrix}\right.\)

Mặt khác: \(n_{hh}=\dfrac{5,04}{22,4}=0,225\left(mol\right)\) \(\Rightarrow\left\{{}\begin{matrix}\%V_{CH_4}=\dfrac{0,075}{0,225}\cdot100\%\approx33,33\%\\\%V_{C_2H_4}=\dfrac{0,1}{0,225}\cdot100\%\approx44,44\%\\\%V_{C_2H_2}=22,23\%\end{matrix}\right.\)

a) PTHH: \(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

b) Ta có: \(n_{Br_2}=\dfrac{11,2}{160}=0,07\left(mol\right)=n_{C_2H_4}\)

\(\Rightarrow\%V_{C_2H_4}=\dfrac{0,07\cdot22,4}{1,72}\cdot100\%\approx91,16\%\) 

\(\Rightarrow\%V_{CH_4}=8,84\%\)

a) \(C_2H_4 + Br_2 \to C_2H_4Br_2\)

b)

\(n_{C_2H_4} = n_{Br_2} = \dfrac{5,6}{160} = 0,035(mol)\\ \%V_{C_2H_4} = \dfrac{0,035.22,4}{0,86}.100\% = 91,16\%\\ \%V_{CH_4} = 100\% - 91,16\% = 8,84\%\)

a) C₂H₄ + Br₂ --> C₂H₄Br₂

b) \(n_{Br_2}=\dfrac{24}{160}=0,15\left(mol\right)\)

PTHH: C₂H₄ + Br₂ --> C₂H₄Br₂

           0,15<--0,15----->0,15

=> \(\%V_{C_2H_4}=\dfrac{0,15.22,4}{7,84}.100\%=42,857\%\)

=> \(\%V_{CH_4}=\dfrac{7,84-0,15.22,4}{7,84}.100\%=57,143\%\)

c) m_C2H4Br2 = 0,15.188 = 28,2 (g)

\(m_{Br_2}=80g\Rightarrow n_{Br_2}=0,5mol\)

\(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

0,5         0,5

\(n_{hh}=\dfrac{28}{22,4}=1,25mol\)

\(\Rightarrow n_{CH_4}=1,25-0,5=0,75mol\)

\(\%V_{CH_4}=\dfrac{0,75}{1,25}\cdot100\%=60\%\)

\(\%V_{C_2H_4}=100\%-60\%=40\%\)

1. \(n_{Br_2}=0,4.0,5=0,2\left(mol\right)\)

PT: \(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

Theo PT: \(n_{C_2H_4}=n_{Br_2}=0,2\left(mol\right)\Rightarrow V_{C_2H_4}=0,2.22,4=4,48\left(l\right)\)

2. \(n_{C_2H_4Br_2}=\dfrac{9,4}{188}=0,05\left(mol\right)\)

PT: \(C_2H_4+Br_2\rightarrow C_2H_4Br_2\)

Theo PT: \(n_{C_2H_4}=n_{C_2H_4Br_2}=0,05\left(mol\right)\)

\(\Rightarrow\%V_{C_2H_4}=\dfrac{0,05.22,4}{1,4}.100\%=80\%\)

\(\Rightarrow\%V_{CH_4}=100-80=20\%\)

\(m_{tăng}=m_{C_2H_2}=0,78\left(g\right)\\PTHH:C_2H_2+2Br_2\rightarrow C_2H_2Br_4\\ n_{C_2H_2}=\dfrac{0,78}{26}=0,03\left(mol\right)\\ n_{hh.khí}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\\\Rightarrow n_{CH_4}=0,1-0,03=0,07\left(mol\right)\\ n.tỉ.lệ.thuận.với.V\\ \%V_{CH_4}=\dfrac{0,07}{0,1}.100\%=70\%;\%V_{C_2H_2}=100\%-70\%=30\%\)