Rotational spectroscopy -1

Which of the following molecules show microwave activity?

• H2

• CO2

• SF6

• CH3Cl

Intensity of microwave spectral lines

• is same

• increases with increase in energy

• increases with decrease in energy

• Goes through maximum

Which of the following molecule shows rotational spectra?

• CO

• CO2

• H2

• N2

In rotational Raman spectrum what is the selection rule for Rayleigh line

• Δ𝐽 = 1

• Δ𝐽 = −1

• Δ𝐽. = +2

• Δ𝐽 = 0

The rotational energy of a diatomic molecule in terms of wave number is

• $E_J\ =\ \frac{h^2}{8\pi^2I}J\left(J+1\right)$

• $E_J\ =\ \frac{h}{8\pi^2IC}J\left(J+1\right)$

• $E_J\ =\ \frac{h^2}{8\pi^2IC}J\left(J+1\right)$

• $E_J\ =\frac{h^2}{8\pi^2I}\ J\left(J+2\right)$

The wave number difference between successive rotational levels of a rigid diatomic molecule is

• 2B J

• BJ(J+1)

• 2BJ(J+1)

• 2BJ(J-1)

The various energy level of a rotational spectrum is given by

• 2B,6B,12B,_ _ _

• 2B,4B,6B,8B,….

• 0,2B,6B,12B,_ _ _

• 0,2B,4B,6B,8B,….

The rotational spectrum of a rigid diatomic rotor consists of equally spaced lines with spacing equal to

• 2B

• B/2

• B

• 4B

The moment of inertia of two isotopic molecules 12CO and *CO are related to the reduced masses according to the formula

• $\frac{I_1}{I_2}=\sqrt{\frac{\mu_1}{\mu_2}}$

• $\frac{I_1}{I_2}=\frac{\mu_1}{\mu_2}$

• $\frac{I_2}{I_1}=\frac{\mu_1}{\mu_2}$

• Non of the above

For isotopic substitution in a diatomic molecule the separation between

rotational energy levels

• Increases

• Decreases

• Same

• Either increase or decreses