\(n_{H_2O}>n_{CO_2}\Rightarrow ankan\)
\(CTchung:C_{\overline{n}}H_{2\overline{n}+2}\)
\(\dfrac{\overline{n}}{2\overline{n}+2}=\dfrac{0.9}{1.4\cdot2}=1.8\)
\(\Rightarrow CH_4,C_2H_6\)
\(Đặt:\)
\(n_{CH_4}=a\left(mol\right),n_{C_2H_6}=b\left(mol\right)\)
\(\left\{{}\begin{matrix}n_C=a+2b=0.9\\n_H=4a+6b=2.8\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}a=0.1\\b=0.4\end{matrix}\right.\)
\(\%CH_4=\dfrac{0.1}{0.5}\cdot100\%=20\%\)
\(\%C_2H_6=80\%\)
\(\Rightarrow B\)
