A compound, containing only carbon, hydrogen and oxygen has a...

On complete oxidation, the obtained compound shows increment in molecular weight of only 16. It means only one oxygen atom is added here. This condition is fulfilled by only aldehyde which on oxidation gives acid. $\mathrm{RCHO} \xrightarrow{[\mathrm{O}]}$$\mathrm{RCOOH}$$Hence, original compound must be an aldehyde. The aldehyde with molecular weight 44 is acetaldehyde.$\underset{$$\begin{array}{l}\text{ Molecular } \\ \text{ weight }=44\end{array}$$}{$\mathrm{CH}_3$$\mathrm{CHO}$} \xrightarrow{[$\mathrm{O}$]} \underset{$\begin{array}{l}\text{ Molecular } \\ \text{ weight }=60\end{array}$}{$\mathrm{CH}_3 \mathrm{COOH}$}