Chapter 11, Problem 11D.5AE

(i)

Interpretation Introduction

Interpretation:

The three active vibrations of ${\text{AB}}_{\text{2}}$ molecule when it is angular havae to be predicted.

Concept introduction:

The complex vibrations exhibited by the polyatomic molecule are known as normal modes of vibrations.  The total number of vibrational degrees of freedom for nonlinear molecule is  $3N-6$.  The total number of vibrational degrees of freedom for linear molecule is $3N-5$.

(ii)

Interpretation Introduction

Interpretation:

The three active vibrations of ${\text{AB}}_{\text{2}}$ molecule when it is linear have to be predicted.

Concept introduction:

As mentioned in the concept introduction in part (a).