How does boiling point relate to molecular mass?

1 Answer
Jul 15, 2017

In general the higher the molecular mass, the greater the boiling point......

Explanation:

Of course, this assumes #"all things being equal"#, which they NEVER are. Boiling point interrogates intermolecular forces. In the absence of other intermolecular forces, hydrogen bonding, dipole-dipole, etc. DISPERSION or Van der Waals forces between molecules relate to the size and transient polarizability of the electron cloud. The bigger the electron cloud (and thus the higher the atomic number, and molecular mass), the higher should be the boiling point.

So, as chemists, we need to illustrate this with data...... Probably the best example we could draw on are the volatilities of the Noble Gases, whose condensation is solely the result of these dispersion forces........

See this site for the data.......