Why does ethanol have a higher boiling point than ethane?

Ethanol has a higher boiling point than ethane primarily due to the presence of hydrogen bonding in ethanol molecules. Ethanol (C2H5OH) has an -OH functional group, which allows for hydrogen bonding between ethanol molecules. This intermolecular force is stronger than the relatively weak London dispersion forces that exist between ethane (C2H6) molecules.

Hydrogen bonding occurs when a hydrogen atom bonded to an electronegative atom (in this case, oxygen) interacts with another electronegative atom (in neighboring ethanol molecules). This creates a stronger attraction between ethanol molecules, requiring more energy to break apart and boil compared to ethane molecules, which only experience weaker London dispersion forces.

As a result, ethanol has a higher boiling point than ethane because it requires more energy to overcome the stronger intermolecular forces between its molecules.