Chapter 3, Problem 3.23NP

Interpretation Introduction

Interpretation: The following relation is to be derived for the internal pressure that obeys Redlich-Kwong equation:

  ${\left(\frac{\partial \text{U}}{\partial {\text{V}}_{\text{m}}}\right)}_{\text{T}}\text{ = }\frac{\text{3a}}{\text{2}\sqrt{\text{T}}{\text{V}}_{\text{m}}({\text{V}}_{\text{m}}\text{ + b)}}$

Concept Introduction: The Redlich-Kwong equation relates pressure, temperature and volume of gas. The expression for the equation is:

  $\text{P = }\frac{\text{RT}}{{\text{V}}_{\text{m}}\text{ - b}}\text{ - }\frac{\text{a}}{\sqrt{\text{T}}{\text{V}}_{\text{m}}{\text{(V}}_{\text{m}}\text{ + b)}}$  - (1)

Where, P represents pressure of the gas, R is Gas constant, V_m is molar volume, T is temperature, and a, b are specific constants for each gas.