Which functional group is characteristic of alcohols?

• A. Carbonyl group (C=O)
• B. Amino group (-NH2)
• C. Hydroxyl group (-OH)
• D. Carboxyl group (-COOH)

Answer: (C)

The functional group that is characteristic of alcohols is the hydroxyl group (-OH). Alcohols are organic compounds that contain one or more hydroxyl groups attached to a carbon atom. The presence of this hydroxyl group is what defines the alcohol family of compounds.

In an alcohol, the -OH group is bonded to a saturated carbon atom (a carbon atom that is connected by single bonds), which allows for a variety of structural forms and chemical behaviors. This group is responsible for the polar nature of alcohols, contributing to their ability to form hydrogen bonds with water, thereby increasing their solubility in polar solvents.

Understanding functional groups is critical for recognizing the chemical properties and behaviors of different organic compounds. The presence of the hydroxyl group not only defines an alcohol but also influences its reactivity and interactions with other molecules in biological systems.