Question

How do intermolecular forces affect evaporation?

Answer 1

Hint Intermolecular forces are those acting in between the molecules which holds them together. If boiling pointing increases then evaporation decreases.

Complete step by step solution:
From the lower classes we are very much familiar about the evaporation process in which the water existing in the liquid form is converted into the gaseous phases with the aid of heat externally applied or absorbed.
In the question it is asked to comment how the intermolecular forces affect the rate of reaction.
The intermolecular forces are those interactions between the various atoms inside the molecules which keeps them together.
We are familiar with the intermolecular forces, the main intermolecular forces are: ion dipole interaction, hydrogen bonding, dipole-dipole interaction and the van der Waals dispersion force.
In all these forces the basic concept is same that is, in the molecules due to the various interaction the one part of the molecule will yield a positive charge and the other part will have a negative charge i.e. as the molecule will have a dipole and these positively charged species arrange pointing towards the negatively charged species if the interaction between the both species is strong enough. And they will be tightly held and this increases the boiling point of the substance. And if the boiling point is increasing that refers to the rate of evaporation.
If the intermolecular molecule is strong enough then the kinetic energy of the molecule will be less, hence the molecules will not get separated and they continue to be in liquid state and because of which the rate of evaporation will be less. On the other hand the molecules that possess the van der Waals interaction force, will attain the kinetic energy and separate out and easily escape into the vapour phase and those molecules will have low boiling point and the rate of evaporation will be more.

Note: The increasing order of the strength of the intermolecular forces should be known to predict the type of interaction, range of boiling point and to have an idea of the rate at which evaporation reaction takes place.
The decreasing order of intermolecular attraction according to its strength is:
Ion-dipole interaction- hydrogen bonding- dipole-dipole interaction- van der Waals force of attraction.