Question

In the alcohols: a) what type(s) of intermolecular force is (are) present? b) what is the strongest intermolecular force present?

Short answer

In alcohols, all three types of intermolecular forces, namely London Dispersion forces, ordinary Dipole-dipole interactions, and Hydrogen bonding, are present. Among these, the strongest is Hydrogen bonding.

Step-by-step solution

Understanding Intermolecular Forces

Intermolecular forces are the forces of attraction between one molecule and another molecule. These could be Dipole-dipole interaction, Hydrogen bonding, and London Dispersion forces. In alcohols, all three types of intermolecular forces can exist depending on their structure.

Identifying Types of Forces in Alcohols

Alcohols, being organic compounds, have carbon and hydrogen atoms forming their core structure. The C-H bond yields a minute molecular dipole, so tiny London Dispersion forces can be present. Moreover, Alcohols contain an -OH group, which is a polar group. This means that dipole-dipole interaction, a force existing between polar molecules, is also present in alcohols.

Determining the Strongest Intermolecular Force

The Oxygen in the -OH group of alcohols forms a highly polar bond with Hydrogen, leading to Hydrogen bonding. Hydrogen bonds are very strong dipole-dipole interactions and are stronger than London Dispersion forces and ordinary dipole-dipole interactions. Hence, the strongest intermolecular force present in alcohols is Hydrogen bonding.