Question

Consider the following statements regarding rotational-vibrational spectroscopy. Determine whether each statement is True or False.
True False  B_e is inversely proportional to the moment of inertia of a diatomic molecule.
True False  Rotational transitions occur typically at shorter wavelengths than vibrational transitions.
True False  R-branch transitions occur at energies above the fundamental vibrational transition.
True False  Vibrational overtones are weak transitions.

Answer 1

1)   B_e is inversely proportional to the moment of inertia of a diatomic molecule (True)

reason : rotational constant : B = h / 8 pi^2 C x I

here ' I ' is rotational constant. so it is inversly proportional to B

2) Rotational transitions occur typically at shorter wavelengths than vibrational transitions. (False)

reason : rotational spectra needs microwave lesser energy . but vibrational spectra needs IR radiation more energy short wave length

3) R-branch transitions occur at energies above the fundamental vibrational transition (True)

P branch - fundamental - Q branch - R branch . this is order

4) Vibrational overtones are weak transitions (True)