Question

Question #b0edb

Answer 1

There are no obvious intermolecular forces to consider save dispersion forces. Therefore, boiling point should increase with the number of electrons. The most volatile material is thus ethane.

Explanation:

Dispersion forces are essentially unequal charge distributions (with respect to the electrons, and thus are very transient, i.e. short-lived) on an atom or molecule. It follows that the more electrons an element has, the greater the degree of intermolecular/interparticle forces. This is the reason that as we go down the halogen series, boiling point increases, and volatility decreases - here we deal with a diatomic molecule. Looking at the Noble gases (atomic rather than molecular species!), boiling points likewise increase down the group.