Final answer:
The functional group present in benzaldehyde is an aldehyde group (-CHO), not a carboxylic acid group (-CO₂H). Benzaldehyde has a carbonyl group bonded to a hydrogen and a benzene ring, distinguishing it from carboxylic acids, which feature both a carbonyl and a hydroxyl group on the same carbon.
Step-by-step explanation:
The functional group present in benzaldehyde is an aldehyde group, specifically the -CHO group. Benzaldehyde is characterized by having a carbonyl group (a carbon-oxygen double bond) with one side bonded to a hydrogen atom and the other side to a carbon atom that is part of a benzene ring. Contrary to the notion of it containing a carboxylic acid group, benzaldehyde does not have the -CO₂H structure that defines carboxylic acids.
Carboxylic acids feature both a carbonyl group and a hydroxyl group (-OH) on the same carbon atom, forming the functional group -COOH. In naming these compounds, such as those derived from benzene, the suffix '-oic acid' is typically added to the parent name of the hydrocarbon. When an aldehyde group is attached to a benzene ring, the parent name is 'benzaldehyde,' and it is recognized by its distinctive aldehyde functional group rather than a carboxylic acid.