a) Chỉ có propylene \(C_3H_6\) phản ứng cộng với brom, ethane \(C_2H_6\) không phản ứng.
\(C_3H_6+Br_2\rightarrow C_3H_6Br_2\left(1\right)\)
\(n\left(Br_2\right)=\dfrac{8}{160}=0,05\left(mol\right)\)
\(\left(1\right)\Rightarrow n\left(C_3H_6\right)=0,05\left(mol\right)\)
\(n\left(hỗn.hợp\right)=\dfrac{V_{hh}}{22,4}=\dfrac{12,395}{22,4}=0,55\left(mol\right)\)
\(\Rightarrow n\left(hỗn.hợp\right)=n\left(C_2H_6\right)+0,05=0,55\)
\(\Rightarrow n\left(C_2H_6\right)=0,55-0,05=0,5\left(mol\right)\)
\(\%V\left(C_2H_6\right)=\dfrac{0,5}{0,55}.100\%=90,91\%\)
\(\Rightarrow\%V\left(C_3H_6\right)=100\%-90,91\%=9,09\%\)
\(m\left(C_2H_6\right)=0,5.30=15\left(g\right)\)
\(m\left(C_3H_6\right)=0,05.42=2,1\left(g\right)\)
\(\%m\left(C_2H_6\right)=\dfrac{15}{15+2,1}.100\%=87,73\%\)
\(\%m\left(C_3H_6\right)=100\%-87,73\%=12,27\%\)
b) \(C_2H_6+\dfrac{7}{2}O_2\rightarrow2CO_2+3H_2O\left(2\right)\)
\(C_3H_6+\dfrac{9}{2}O_2\rightarrow3CO_2+3H_2O\left(3\right)\)
\(\left(2\right);\left(3\right)\Rightarrow n\left(O_2\right)=0,5.3,5+0,05.4,5=1,9\left(mol\right)\)
\(V\left(O_2\right)=1,9.22,4=42,56\left(lít\right)\)
\(V\left(kk\right)=\dfrac{42,56}{20\%}=212,8\left(lít\right)\)
\(\left(2\right);\left(3\right)\Rightarrow n\left(CO_2\right)=0,5.2+0,05.3=1,15\left(mol\right)\)
\(V\left(CO_2\right)=1,15.22,4=25,76\left(lít\right)\)