Which of the following is a functional group commonly found in alcohols?

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

Answer: (D)

Verified step by step guidance

1. Identify the functional groups listed in the problem: Carboxyl group (-COOH), Carbonyl group (C=O), Amino group (-NH2), and Hydroxyl group (-OH).
2. Recall the definition of a functional group: a specific group of atoms within a molecule that is responsible for a characteristic chemical reaction of that molecule.
3. Understand that alcohols are organic compounds characterized by the presence of a hydroxyl group (-OH) attached to a carbon atom.
4. Compare the functional groups listed with the characteristic functional group of alcohols. Alcohols specifically contain the hydroxyl group (-OH).
5. Conclude that the functional group commonly found in alcohols is the hydroxyl group (-OH), as it is the defining feature of alcohols.