Which functional group is characteristic of organic aldehydes?

The functional group that is characteristic of organic aldehydes is the CHO functional group. Aldehydes are defined by the presence of a carbonyl group (C=O) bonded to a carbon atom that also has a hydrogen atom attached to it. This configuration gives rise to the CHO structure, where the carbonyl carbon is directly connected to a hydrogen atom.

In organic chemistry, the unique structure of aldehydes plays a key role in their reactivity and properties. The presence of the carbonyl group contributes to their characteristic chemical behavior, such as participating in reactions like nucleophilic addition and oxidation. The simple formula RCHO, where R represents an alkyl or aryl group, encapsulates this functional group, underscoring its importance in identifying and classifying aldehydes.

Other options do not represent the functional group typically associated with aldehydes. The hydroxyl (OH) group is indicative of alcohols, while C-C double and triple bond functional groups signify alkenes and alkynes, respectively. These distinctions clarify the unique nature of aldehydes in organic chemistry.