\(\overline{M}=\frac{40}{3}.2=\frac{80}{3}\)
\(\left\{{}\begin{matrix}n_{CH4}:a\left(mol\right)\\n_{O2}:b\left(mol\right)\end{matrix}\right.\Rightarrow\frac{16a+32b}{a+b}=\frac{80}{3}\)
\(\Leftrightarrow\frac{32}{3}a=\frac{16}{3}b\Leftrightarrow\frac{a}{b}=\frac{1}{2}\)
Giả sử \(\left\{{}\begin{matrix}a=1\\b=2\end{matrix}\right.\)
\(CH_4+2O_2\underrightarrow{^{to}}CO_2+H_2O\)
1_____2____________________
\(\Rightarrow\) Phản ứng hoàn toàn