Chapter 11, Problem 11B.1BE

Interpretation Introduction

Interpretation:

The moment of inertia around the threefold symmetry axis and the rotational constant of ${}^{\text{31}}{\text{P}}^{\text{1}}{\text{H}}_{\text{3}}$ molecule has to be calculated.

Concept introduction:

The moment of inertia of a molecule about an axis passing through the centre of mass is directly proportional to the reduced mass of the molecule and the bond length of the molecule.  The rotational energy of a molecule is usually expressed in terms of its rotational constant.