Chapter 13, Problem 60A

Interpretation Introduction

Interpretation: The effect of intermolecular forces on vapor pressure is to be determined.

Concept introduction:

A liquid is a nearly incompressible fluid and has the shape of its container and maintains a (almost) constant volume under all conditions of pressure. The volume is fixed if the temperature and pressure are both constant.

Answer to Problem 60A

Vapor pressure varies inversely with the strength of intermolecular forces.

Explanation of Solution

Vapor pressure rises with temperature and is a measurement of a substance's capacity to transform into a gaseous or vapor state.

The pressure that vapor molecules apply to a solid or liquid surface in an equilibrium state is referred to as the surface's vapor pressure. The intermolecular forces between the liquid's atoms are inversely correlated with the vapor pressure of the liquid. This relationship exists because, if the liquid exhibited stronger intermolecular interactions, its rate of evaporation would be much slower, which would result in lower vapor pressure. Like the last example, if the liquid has weak intermolecular interactions, its rate of evaporation will also be very high, leading to increased vapor pressure.