The reactive portion of organic acids is known as what functional group?

The reactive portion of organic acids is referred to as the carboxyl group. The carboxyl group consists of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group (–OH). This structure not only imparts acidic properties to organic compounds but also makes them reactive in various chemical reactions.

The presence of the carboxyl group (–COOH) is what defines a compound as a carboxylic acid. This functional group is significant in organic chemistry, as it participates in essential reactions such as esterification and decarboxylation, and plays a crucial role in biological systems, influencing the behavior of amino acids and fatty acids.

In contrast, the hydroxyl group (–OH) is associated with alcohols and phenols, the amine group (–NH2) is tied to amines, and the aldehyde group (–CHO) pertains to aldehydes, each with distinct chemical properties that do not define organic acids. Hence, the carboxyl group is uniquely responsible for the characteristics attributed to organic acids.