MP Assistant Professor Exam 2022
Raman spectroscopy depends on the change in:
- (A) Dipole moment
- (B) Moment of inertia
- (C) Permanent dipole moment
- (D) Polarizability
Answer: (D) Polarizability
Explanation: The selection rule for Raman spectroscopy requires that a vibration or rotation must cause a change in the molecular polarizability. This is in contrast to IR spectroscopy, which requires a change in the dipole moment.
(A) and (C) Dipole Moment: These are the requirements for Infrared (IR) Spectroscopy. IR depends on the change in the dipole moment during a vibration.
(B) Moment of Inertia: Changes in the moment of inertia are associated with Rotational (Microwave) Spectroscopy, not Raman or IR vibrational spectroscopy.