Chapter 7, Problem 7.25NP

(a)

Interpretation Introduction

Interpretation:

The value of V_c should be calculated assuming methane is an ideal gas.

Concept Introduction :

For an ideal gas,

  $V_C=\frac{R{T}_C}{P_C}$

  $\begin{array}{l}{V}_C\text{ - critical volume}\\ \text{R - universal gas constant}\\ T_C\text{ - critical temperature}\\ P_C\text{ - critical pressure}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The value of V_c should be calculated assuming methane is a van der Waals gas.

Concept Introduction :

For a van der Waals gas,

  $z_C=\frac{P_C{V}_C}{R{T}_C}=\frac{3}{8}$

  $\begin{array}{l}{z}_C\text{ - critical compression factor}\\ V_C\text{ - critical volume}\\ \text{R - universal gas constant}\\ T_C\text{ - critical temperature}\\ P_C\text{ - critical pressure}\end{array}$

(c)

Interpretation Introduction

Interpretation:

The value of V_c should be calculated assuming methane is a Redlich-Kwong gas.

Concept Introduction :

For a Redlich-Kwong gas,

  $z_C=\frac{P_C{V}_C}{R{T}_C}=0.333$

Here,

  $\begin{array}{l}{z}_C\text{ - critical compression factor}\\ V_C\text{ - critical volume}\\ \text{R - universal gas constant}\\ T_C\text{ - critical temperature}\\ P_C\text{ - critical pressure}\end{array}$