Which of the following functional groups is characteristic of alcohols?

• A. $–{\mathrm{CO}}_{2}H$ (carboxyl group)
• B. $–\mathrm{OH}$ (hydroxyl group)
• C. $–{\mathrm{NH}}_2$ (amino group)
• D. $–{\mathrm{CO}}_{2}R$ (ester group)

Answer: (B)

Verified step by step guidance

1. Identify the functional groups listed in the problem: carboxyl group (–CO\_2H), hydroxyl group (–OH), amino group (–NH\_2), and ester group (–CO\_2R).
2. Recall the definition of an alcohol: an organic compound where a hydroxyl group (–OH) is directly bonded to a saturated carbon atom.
3. Understand that the hydroxyl group (–OH) is the characteristic functional group of alcohols, distinguishing them from other classes of compounds.
4. Recognize that the carboxyl group (–CO\_2H) is characteristic of carboxylic acids, the amino group (–NH\_2) is characteristic of amines, and the ester group (–CO\_2R) is characteristic of esters.
5. Conclude that the correct functional group characteristic of alcohols is the hydroxyl group (–OH).