Which of the following statements best describes whether the molecule CH3CH2OH (ethanol) is hydrophilic?

• A. Ethanol is hydrophilic only at very high temperatures.
• B. Ethanol is hydrophilic because it can form hydrogen bonds with water.
• C. Ethanol is neither hydrophilic nor hydrophobic.
• D. Ethanol is hydrophobic because it cannot interact with water.

Answer: (B)

Verified step by step guidance

1. Understand the meaning of hydrophilic: A hydrophilic molecule is one that can interact well with water, often through hydrogen bonding or polarity, allowing it to dissolve or mix with water.
2. Analyze the structure of ethanol (CH3CH2OH): It has a polar hydroxyl group (-OH) and a nonpolar ethyl group (CH3CH2-). The hydroxyl group is capable of forming hydrogen bonds with water molecules.
3. Recognize that the ability to form hydrogen bonds with water makes ethanol soluble and able to interact well with water, which is a key characteristic of hydrophilic substances.
4. Consider the nonpolar ethyl group: While it is hydrophobic, the presence of the polar hydroxyl group dominates the interaction with water, making ethanol overall hydrophilic.
5. Conclude that ethanol is hydrophilic because it can form hydrogen bonds with water, which explains why it mixes well with water at normal temperatures.