Question

In which of the following the rotational constant value in diatomic molecules depends on
(A) Moment of inertia and bond length.
(B) Nature of molecules.
(C) The only b is correct.
(D) Both a and b are correct.

Answer 1

Hint :We know that the rotational constant value in diatomic molecules depends on: both moment of inertia and bond length. The collision is perfectly elastic and there is no force of attraction or repulsion between the molecules.

Complete Step By Step Answer:
The moment of inertia of the molecule. Diatomic molecules with the general formula AB have one normal mode of vibration which involves the stretching of the A-B bond. In the gas phase the molecule can rotate about an axis. The rotational constant depends on the moment of inertia of the molecule which varies with the vibrational quantum number.
Rotational kinetic energy at a given temperature of the translational kinetic energy of a gas molecule. The translational kinetic energy and rotational kinetic energy both obey Maxwell’s law of distribution independent of each other. Different molecules have different rotational kinetic energy. Ideal gases only possess translational kinetic energy but non-ideal gases possess smaller rotational kinetic energy.
Therefore the correct answer is option D.

Note :
Remember that Kinetic theory of ideal gases explains that All gases consist of molecules, molecules are rigid, spherical, and elastic in nature The size of the molecule is negligible compared to the average distance between the molecules. Molecules are in continuous random motion and in this phenomenon; the molecules collide with one another and also the walls of the container.