$m_{O_2}=20,8 gam\Rightarrow \begin{cases}44n_{CO_2}+18n_{H_2O}=14,6+20,8 \\n_{CO_2}:n_{H_2O}=6:5 \end{cases}\Rightarrow \begin{cases}n_{CO_2}=0,6 mol \\n_{H_2O}=0,5 mol \end{cases}$$X:C_xH_yO_z\Rightarrow x:y:z=0,6:(2.0,5):(2.0,6+0,5-\frac{2.14,56}{22,4})=3:5:2$
$M_X=146\Rightarrow X:C_6H_{10}O_4\Rightarrow X:este$
$7,3 gam X\Leftrightarrow n_X=0,05 mol\Rightarrow $
$*)n_{ancol}=0,05 mol\Rightarrow M_{ancol}=92\Leftrightarrow M_{HO-R-OH}=92:loai$
$*)n_{ancol}=0,1\Rightarrow \overline{M} _{ancol}=46\Rightarrow [C_2H_5OH;C_2H_5OH];[CH_3OH;C_3H_7OH]$
$\Rightarrow X:C_2H_5OOC-COOC_2H_5$
$CH_3OOC-COO-CH_2-CH_2-CH_3$
$CH_3OOC-COO-CH(CH_3)_2$
$\Rightarrow Chon:C$