Chapter 18, Problem 18.38E

Interpretation Introduction

Interpretation:

The value of $q_{\text{rot}}$ for ${\text{PH}}_{\text{3}}$$\left(\sigma =3\right)$ at $273\text{K}$ is to be determined.

Concept introduction:

The $q_{\text{rot}}$ for polyatomic molecules is given by the formula,

$q_{\text{rot}}=\frac{{\pi }^{1/2}}{\sigma }{\left(\frac{T^3}{{\theta }_{\text{r, A}}\cdot {\theta }_{\text{r, B}}\cdot {\theta }_{\text{r, C}}}\right)}^{1/2}$

The value of ${\theta }_r$ can be expressed in terms of moment of inertia as given below.

${\theta }_r=\frac{h^2}{8{\pi }^2{I}_{\text{A}}k}$