\(n_{CO_2}=\dfrac{19,8}{44}=0,45\left(mol\right);n_{H_2O}=\dfrac{5,4}{18}=0,3\left(mol\right)\\ \Rightarrow n_{ankin}=n_{CO_2}-n_{H_2O}=0,15\left(mol\right)\)
\(\xrightarrow[]{\text{Bảo toàn liên kết }\pi}n_{H_2}=2n_{ankin}=0,3\left(mol\right)\)
Vậy \(\left\{{}\begin{matrix}n_{ankin}=0,15\left(mol\right)\\n_{H_2}=0,3\left(mol\right)\end{matrix}\right.\)