Which of the following molecules experiences the strongest intermolecular forces?

• A. CH4
• B. CH3OH

Answer: (B)

Verified step by step guidance

1. Identify the types of intermolecular forces present in each molecule. For CH4 (methane), the primary intermolecular forces are London dispersion forces, which are relatively weak and arise from temporary dipoles.
2. For CH3OH (methanol), consider that it contains an -OH group, which allows for hydrogen bonding, a much stronger type of intermolecular force compared to London dispersion forces.
3. Recall that hydrogen bonding occurs when hydrogen is directly bonded to highly electronegative atoms like oxygen, nitrogen, or fluorine, creating strong dipole-dipole attractions.
4. Compare the strength of the intermolecular forces: London dispersion forces in CH4 versus hydrogen bonding in CH3OH. Hydrogen bonding is significantly stronger and leads to higher boiling points and stronger intermolecular attractions.
5. Conclude that CH3OH experiences the strongest intermolecular forces due to the presence of hydrogen bonding, whereas CH4 only has weaker London dispersion forces.