Vaporization overcomes intermolecular forces specific to each substance

Steps:

• Identify intermolecular forces: temporary dipole-induced dipole (London dispersion) occur in all molecules but are the only force in nonpolar substances.
• Analyze polarity: nonpolar molecules like O₂ rely solely on dispersion forces; polar molecules have dipole-dipole or hydrogen bonding.
• Evaluate each option: check if the liquid-to-gas transition involves only dispersion forces.
• Select the nonpolar substance without stronger forces.

Why C is correct:

• O₂ is a nonpolar diatomic molecule, so intermolecular forces are only London dispersion forces (temporary dipole-induced dipole), as defined for nonpolar gases.

Why the others are wrong:

• A: H₂O(l) involves hydrogen bonding, stronger than dispersion forces.
• B: C₂H₅OH(l) involves hydrogen bonding between -OH groups.
• D: CH₃Cl(l) has permanent dipole-dipole forces due to polarity.

Final answer: C