Chapter 14, Problem 14.79E

Interpretation Introduction

(a)

Interpretation:

The number of IR-active vibrations for ${\text{CH}}_{\text{4}}$ is to be determined.

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 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 total number of vibrational degrees of freedom for nonlinear molecule is represented by $3N-6$.

Interpretation Introduction

(b)

Interpretation:

The number of IR-active vibrations for ${\text{CH}}_{\text{3}}\text{Cl}$ is to be determined.

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 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 total number of vibrational degrees of freedom for nonlinear molecule is represented by $3N-6$.

Interpretation Introduction

(c)

Interpretation:

The number of IR-active vibrations for ${\text{CH}}_{\text{2}}{\text{Cl}}_2$ is to be determined.

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 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 total number of vibrational degrees of freedom for nonlinear molecule is represented by $3N-6$.

Interpretation Introduction

(d)

Interpretation:

The number of IR-active vibrations for ${\text{CHCl}}_3$ is to be determined.

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 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 total number of vibrational degrees of freedom for nonlinear molecule is represented by $3N-6$.

Interpretation Introduction

(e)

Interpretation:

The number of IR-active vibrations for ${\text{CCl}}_4$ is to be determined. Whether the answers make sense in the progression from methane to fully substituted methane is to be stated.

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 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 total number of vibrational degrees of freedom for nonlinear molecule is represented by $3N-6$.