Chapter 11, Problem 11C.5BE

(i)

Interpretation Introduction

Interpretation:

The relative numbers of ${\text{Br}}_{\text{2}}$ molecules in the second and first excited vibrational state has to be calculated at $\text{298K}$.

Concept introduction:

The complex vibrations exhibit by the polyatomic molecule is known as normal modes of vibrations. The vibrational modes of a molecule are IR or Raman active. If a molecule has a centre of symmetry, then the modes which are IR-active will be Raman inactive and the modes that are IR-inactive will be Raman active. The relative population at two vibrational states is given by Boltzmann distribution as shown below.

  $\frac{N_2}{N_1}=\exp \left(\frac{-hc\tilde{v}}{kT}\right)$

(ii)

Interpretation Introduction

Interpretation:

The relative number of ${\text{Br}}_{\text{2}}$ molecules in the second and first excited vibrational state has to be calculated at $\text{298K}$.

Concept introduction:

As mentioned in the concept of introduction in part (i).