What is the primary functional group in an alkene?

In alkenes, the primary functional group is the carbon-carbon double bond, represented as C=C. This double bond is what characterizes alkenes, distinguishing them from alkanes, which contain only single carbon-carbon bonds, and other functional groups. The presence of this double bond also influences the reactivity and properties of alkenes, making them more reactive than alkanes.

The other functional groups listed do not apply to alkenes. Alkynes contain a carbon-carbon triple bond, while alcohols contain a hydroxyl group (-OH), and carboxylic acids feature a carboxyl group (-COOH). Each of these groups has its own unique characteristics and nomenclature rules, further emphasizing that alkenes are specifically recognized by the presence of the C=C double bond. Thus, the correct identification of the functional group is essential for understanding the behavior and classification of these compounds in organic chemistry.