Final Answer:
The structure CH₃CH₂CH₂CHO is an aldehyde. Thus the correct option is D.
Step-by-step explanation:
An aldehyde can be recognized by the presence of the functional group -CHO. In this case, option d) CH₃CH₂CH₂CHO contains the -CHO group, which signifies it as an aldehyde. The -CHO group consists of a carbon atom double-bonded to an oxygen atom and single-bonded to a hydrogen atom. The other options, a) CH₃CH₂CH₂CH₂OH, b) CH₃CH₂COCH₃, and c) CH₃CH₂COOCH₃, do not possess this characteristic aldehyde functional group.
CH₃CH₂CH₂CHO showcases the structure of an aldehyde compound, specifically butyraldehyde. The presence of the -CHO group at the end of the carbon chain denotes the characteristic feature of an aldehyde. This structure distinguishes it from other compounds like alcohols (option a), ketones (option b), or esters (option c). Aldehydes are notable for their versatile applications in various chemical reactions, including oxidation, reduction, and condensation reactions, making them crucial in both industrial and biological processes.
Understanding functional group identification aids in categorizing compounds, which is fundamental in organic chemistry analysis and synthesis. In this context, recognizing the -CHO group helps in distinguishing aldehydes from other organic compounds, thereby aiding in their identification and utilization in diverse chemical processes. Therefore the right option is D.