a, Gọi CTCT : $C_{\overline{n}} H_{2\overline{n} +1} OH$
$C_{\overline{n}} H_{2\overline{n} +1}OH + O_2 \xrightarrow{{t°}} \overline{n} CO_2 + (\overline{n} +1)H_2O$
$n_{CO_2} = 0,25 (mol)$
$n_{H_2O} = 0,35 (mol)$
$\Rightarrow \dfrac{0,25}{\overline{n}} = \dfrac{0,35}{\overline{n}+1}$
$\Rightarrow \overline{n} =1,8$
$\Rightarrow CH_3OH, C_2H_5OH$
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