Question

Why do molecules of methanol form hydrogen bonds but methane doesn't?

a) Methanol has a polar covalent bond
b) Methanol is a larger molecule
c) Methanol has a higher boiling point
d) Methane is a nonpolar molecule

Answer 1

Methanol forms hydrogen bonds due to its polar -OH group and ability to act as a hydrogen bond donor and acceptor, while methane cannot form hydrogen bonds since it is a nonpolar molecule with no significant partial charges.

Step-by-step explanation:

The molecules of methanol (CH3OH) are capable of forming hydrogen bonds because methanol contains a polar -OH (hydroxyl) group, where the oxygen has two lone pairs of electrons and is more electronegative than hydrogen. This difference in electronegativity leads to a polar covalent bond, making methanol a polar molecule with a partial negative charge on the oxygen and a partial positive charge on the hydrogen. Methanol can therefore act as both a hydrogen bond donor and acceptor. In contrast, methane (CH4) is a nonpolar molecule because it is symmetric, with hydrogen atoms evenly spaced around the central carbon atom, resulting in an even distribution of charges and no area with a significant partial charge to form hydrogen bonds.