Chapter 10, Problem 10.125SP

Interpretation Introduction

Interpretation:

Whether water molecule would absorb IR radiation based upon the symmetric, anti-symmetric modes should be decided.

Concept introduction:

The gases that cannot absorb IR radiation are termed as IR inactive and categorized into greenhouse gases. The two such gases are abundant in atmosphere such as ${\text{O}}_{\text{2}}$ and ${\text{N}}_{\text{2}}$. For a molecule to be IR active its vibrational modes must exhibit a change in dipole moment. For instant, the anti-symmetric mode of ${\text{CO}}_{\text{2}}$ shows a fluctuation in dipole moment and hence is IR active.