Which intermolecular forces are present in a molecule of CH\(_3\)OH (methanol)?

• A. London dispersion forces, dipole-dipole interactions, and hydrogen bonding
• B. Only dipole-dipole interactions and London dispersion forces
• C. Only London dispersion forces
• D. Only hydrogen bonding

Answer: (A)

Verified step by step guidance

1. Identify the types of atoms and bonds present in the molecule CH\(_3\)OH (methanol). Methanol contains carbon (C), hydrogen (H), and oxygen (O) atoms, with an -OH (hydroxyl) group attached to a methyl group (CH\(_3\)).
2. Determine if the molecule is polar. The presence of the electronegative oxygen atom bonded to hydrogen creates a polar O-H bond, making the molecule overall polar. This polarity allows for dipole-dipole interactions.
3. Recognize that all molecules exhibit London dispersion forces (also called van der Waals forces) due to temporary fluctuations in electron density, so these forces are always present regardless of polarity.
4. Check for hydrogen bonding. Hydrogen bonding occurs when hydrogen is directly bonded to highly electronegative atoms like oxygen, nitrogen, or fluorine. Since methanol has an O-H bond, it can form hydrogen bonds with other methanol molecules.
5. Conclude that methanol exhibits London dispersion forces, dipole-dipole interactions due to its polarity, and hydrogen bonding because of the O-H group.