Chapter 1, Problem 1.15CP

Interpretation Introduction

Interpretation:The reason for the attractive interactions between the molecules of gas to make pressure less than that by an ideal gas equation needs to be explained.

Concept Introduction: The ideal gas equation gives the relations between P,V, n and T of gases. It can be written as:

  $\text{PV = nRT}$

Here, P is pressure of the gas, V is volume of the gas, n is number of moles, R is Universal gas constant and T is temperature.

Usually gases do not follow ideal behavior under all conditions of pressure, temperature and volumes. The relation of P, V, n and T of real gases can be given by Vander Waals equation:

  $\left(\text{P + }\frac{{\text{n}}^{\text{2}}\text{a}}{{\text{V}}^{\text{2}}}\right)\left(\text{V- n b}\right)\text{ = nRT}$

Hence $\text{P = }\frac{\text{nRT}}{\text{ V-nb}}\text{ - }\frac{{\text{n}}^{\text{2}}\text{a}}{{\text{V}}^{\text{2}}}$