$C_nH_{2n+2}+\frac{3n+1}{2}O_2\rightarrow nCO_2+(n+1)H_2O$ $a na$$\Rightarrow \begin{cases}a=\frac{7,2}{14n+2} \\ na=0,5 \end{cases}\Rightarrow n=5\Rightarrow C_5H_{12}\Rightarrow CH_3-CH_2-CH(CH_3)-CH_3$
$C_nH_{2n+2}+\frac{3n+1}{2}O_2\rightarrow nCO_2+(n+1)H_2O$ $a na$$\Rightarrow \begin{cases}a=\frac{7,2}{14n+2} \\ na=0,5 \end{cases}\Rightarrow n=5\Rightarrow C_5H_{10}\Rightarrow CH_3-CH_2-CH(CH_3)-CH_3$
$C_nH_{2n+2}+\frac{3n+1}{2}O_2\rightarrow nCO_2+(n+1)H_2O$ $a na$$\Rightarrow \begin{cases}a=\frac{7,2}{14n+2} \\ na=0,5 \end{cases}\Rightarrow n=5\Rightarrow C_5H_{1
2}\Rightarrow CH_3-CH_2-CH(CH_3)-CH_3$