Is the $\mathrm{carbonyl}$ functional group considered hydrophobic or hydrophilic?

• A. Hydrophilic, because the $\mathrm{carbonyl}$ group can form hydrogen bonds with water
• B. Hydrophobic, because the $\mathrm{carbonyl}$ group cannot interact with water
• C. Hydrophobic, because it contains only nonpolar bonds
• D. Neither hydrophobic nor hydrophilic, because it is chemically inert

Answer: (A)

Verified step by step guidance

1. Understand the nature of the carbonyl group: it consists of a carbon atom double-bonded to an oxygen atom (C=O).
2. Recognize that the oxygen atom in the carbonyl group is highly electronegative, creating a polar bond with the carbon atom.
3. Recall that polar groups can interact with water molecules through dipole-dipole interactions and hydrogen bonding.
4. Since the carbonyl oxygen has lone pairs, it can act as a hydrogen bond acceptor, allowing it to form hydrogen bonds with water.
5. Conclude that because the carbonyl group can engage in hydrogen bonding with water, it is considered hydrophilic.