Teaching Intermolecular Forces to First-Year Undergraduate Students

A recent article in this Journal provides an excellent overview of intermolecular forces of attraction (IMFs) at a first-year level by using plots of boiling point versus the number of electrons per molecule for the hydrides of groups IV-VII. However, references to IMFs in introductory chemistry courses are typically extended to other physical properties, such as melting point, viscosity, surface tension, and so forth. At the first-year level, we feel that a degree of circumspection is required lest it be assumed that all of these physical properties necessarily have a similar, simple correspondence to IMFs as that which is generally shown by boiling points.