We’re being asked to determine the compound with the highest boiling point among the choices.
Recall that the boiling and melting point of a compound depends primarily on its mass and intermolecular forces. The types of intermolecular forces (IMF) are:
1. Hydrogen bonding – occurs in compounds where hydrogen is directly connected to an electronegative element such as N, O, or F; strongest IMF
2. Dipole-dipole interaction – occurs between two polar covalent compounds; 2nd strongest IMF
3. London dispersion forces – occurs in all compounds and is the primary IMF exhibited by nonpolar compounds; weakest IMF
Since the given compounds have similar molecular weights, we only need to determine the type of IMF present.