Chemistry Vignettes: Vibrational Modes
A video that describes the vibrational modes of polyatomic molecules and how these modes determine whether the molecules are IR inactive or IR active.
Play the video micro-lecture Chemistry Vignettes: Vibrational Modes to describe the vibrational modes of polyatomic molecules.
Explain that only some vibrational modes (those that lead to a fluctuating dipole) result in absorption of IR light energy.
Introduce the terms “IR active molecules” and “IR inactive molecules” by using the CO2 molecule as an example and describe its different modes of vibration.