Question

Molecule A is a non-polar, covalently bonded diatomic molecule with a molar mass of 34 g/mol. Molecule B is a non-polar, covalently bonded diatomic molecule with a molar mass of 24 g/mol. Molecule C is a polar covalently bonded diatomic molecule with a molar mass of 34 g/mol. Which of these three likely have the lowest boiling point?

Answer 1

Answer:

Molecule B

Explanation:

The strongest intermolecular force in Molecule B is the London dispersion force.

It is the weakest of the intermolecular forces, so Molecule B has the lowest boiling point.

A is wrong. Molecule A has a higher molecular mass than Molecule B. Its dispersion forces are stronger, and its boiling point is higher.

C is wrong. Molecule C has dipole-dipole forces. These forces are stronger than dispersion forces, so Molecule C has the highest boiling point.