Which of the following functional groups is present in the structure of an $\mathrm{alcohol}$?

• A. $\mathrm{Carboxyl} \mathrm{group} \left(\mathrm{–COOH}\right)$
• B. $\mathrm{Hydroxyl} \mathrm{group} \left(\mathrm{–OH}\right)$
• C. $\mathrm{Carbonyl} \mathrm{group} (\mathrm{–C}=O)$
• D. $\mathrm{Amino} \mathrm{group} \left(\mathrm{–NH}{2}_{}\right)$

Answer: (B)

Verified step by step guidance

1. Identify the functional group associated with alcohols. Alcohols are characterized by the presence of a hydroxyl group.
2. Understand the structure of a hydroxyl group. It consists of an oxygen atom bonded to a hydrogen atom, represented as \( \text{-OH} \).
3. Differentiate between the given options: Carboxyl group (\( \text{-COOH} \)), Carbonyl group (\( \text{C=O} \)), and Amino group (\( \text{-NH}_2 \)).
4. Recognize that none of the other groups (Carboxyl, Carbonyl, Amino) match the structure of a hydroxyl group.
5. Conclude that the functional group present in the structure of an alcohol is the hydroxyl group.