Which of the following functional groups is present in the molecule ${\mathrm{ethanol}}_{}$?

• A. $\text{Hydroxyl group (}-\mathrm{OH}\text{)}$
• B. $\text{Carboxyl group (}-\mathrm{COOH}\text{)}$
• C. $\text{Amino group (}-\mathrm{NH}{2}_{}\text{)}$
• D. $\text{Carbonyl group (}-\mathrm{CO}\text{-)}$

Answer: (A)

Verified step by step guidance

1. Identify the molecular structure of ethanol, which is \( \text{C}_2\text{H}_5\text{OH} \).
2. Recognize that ethanol is an alcohol, which is characterized by the presence of a hydroxyl group.
3. Understand that a hydroxyl group is represented by \( -\text{OH} \) in organic chemistry.
4. Compare the functional groups listed: Hydroxyl group, Carboxyl group, Amino group, and Carbonyl group.
5. Determine that the hydroxyl group \( -\text{OH} \) is the functional group present in ethanol.