Question

Water, H2O, and methane, CH4, are both covalent substances. Why is water a liquid at room temperature while methane is a gas? A Methane must be polar. B Carbon compounds tend to be gases. C Water must be nonpolar. D Water has stronger intermolecular forces.

Answer 1

The right answer is D.

Intermolecular forces lead to the assembly of microscopic systems. They are responsible for the cohesion of matter in most macroscopic phases. These are weak forces compared to covalent bond strengths. They do not modify the nature of the molecular species and only influence their mode of assembly. The most well-known intermolecular bonds are the Van der Waals bond and the hydrogen bond.

The greater the intermolecular forces, the more the aspect of the element will tend to be more condensed (gas <liquid <solid).