The table below shows the normal boiling points of benzene and benzene derivatives.
(a) How many of these compounds exhibit dispersion interactions?

Key Concepts

Dispersion Interactions

Dispersion interactions, also known as London dispersion forces, are weak intermolecular forces that arise from temporary fluctuations in electron density within molecules. These fluctuations create instantaneous dipoles that induce dipoles in neighboring molecules, leading to an attractive force. All molecules, regardless of polarity, exhibit dispersion interactions, but they are particularly significant in nonpolar compounds.

Boiling Point and Intermolecular Forces

The boiling point of a substance is the temperature at which its vapor pressure equals the external pressure, allowing it to transition from liquid to gas. Intermolecular forces, including dispersion interactions, hydrogen bonding, and dipole-dipole interactions, play a crucial role in determining boiling points. Stronger intermolecular forces typically result in higher boiling points, as more energy is required to overcome these attractions.

Benzene and Its Derivatives

Benzene is an aromatic hydrocarbon with a stable ring structure, characterized by its delocalized π electrons. Its derivatives are compounds that contain the benzene ring but may have different functional groups attached. The presence of these functional groups can influence the types and strengths of intermolecular forces present, including dispersion interactions, which are relevant for understanding their boiling points.