Which of these molecules exhibit the most number of different intermolecular forces?

• A.
• B.
• C.

Answer: (B)

Verified step by step guidance

1. Identify the types of intermolecular forces: The main types of intermolecular forces are London dispersion forces, dipole-dipole interactions, and hydrogen bonding.
2. Analyze the first molecule (propane): Propane (C3H8) is a nonpolar molecule, so it primarily exhibits London dispersion forces.
3. Analyze the second molecule (formaldehyde): Formaldehyde (CH2O) is a polar molecule due to the difference in electronegativity between carbon and oxygen, leading to dipole-dipole interactions. It also has London dispersion forces.
4. Consider hydrogen bonding: For hydrogen bonding to occur, a molecule must have a hydrogen atom attached to a highly electronegative atom (N, O, or F). Neither propane nor formaldehyde can form hydrogen bonds.
5. Compare the molecules: Propane exhibits only London dispersion forces, while formaldehyde exhibits both London dispersion forces and dipole-dipole interactions. Therefore, formaldehyde exhibits more types of intermolecular forces.