Overtones are observed in the vibrational spectra of diatomic molecules when:a)Anharmonicity is large.b)Anharmonicity is absent.c)Vibrational and rotational modes are coupled.d)An alternating electric field is applied.Correct answer is option 'C'. Can you explain this answer?

Question

Answer

Explanation:

Introduction:
Overtones are observed in the vibrational spectra of diatomic molecules when vibrational and rotational modes are coupled.

Vibrational and rotational modes:
Vibrational modes refer to the movements of atoms within a molecule, while rotational modes refer to the rotation of the molecule as a whole. In diatomic molecules, the vibrational and rotational modes are coupled, meaning that they interact with each other.

Overtones:
Overtones are higher energy states of a molecule's vibrational mode. They are observed when a molecule absorbs energy that is greater than the energy required to excite the fundamental vibrational mode.

Explanation:
When vibrational and rotational modes are coupled, the energy levels of the molecule become more complex. The result is that the vibrational modes split into sub-levels, and overtones are observed when the molecule absorbs energy that corresponds to these sub-levels.

In contrast, if anharmonicity is absent, the molecule's vibrational modes would be simple and would not split into sub-levels. Similarly, an alternating electric field does not affect the vibrational modes of a molecule.

Therefore, the correct option is C, which states that overtones are observed in the vibrational spectra of diatomic molecules when vibrational and rotational modes are coupled.

Answer

Maybe a case of Fermi Resonance

Similar Chemistry Doubts

The vibrational energy levels, v11 = 0 and v1 = 1 of a diatomic molecule are separated by 2143 cm-1. Its Anharmonicity (ωe Xe ) is 14 cm-1. The values of ωe (in cm-1) and first overtone (cm-1) of this molecules are respectively.

Vibrational transitions are always accompanied by transitions.

The fundamental vibration frequency and rotational constant of carbon monoxide molecule are 6.5 x 1013 s-1 and 1.743 x 1011 s-1 respectively. The rotational will have the same energy as ir would have in its first vibrational states with no rotational energy is

The different types of energies associated with a molecule are __________.

The following data wire obtained from the vibrational fine structure in the vibronic spectrum of a diatomic molecule|Whereωe is the energy associated with the natural frequency of vibration and xe is the anharmonicity constant. The dissociation energy (D e) of the molecule is

Top Courses for Chemistry

Suggested Free Tests

Related Content

Schools

Competitive Examinations

Quick Access Links

Technical Exams