Chapter 2 Multiple Choice Questions

. Calculate the moment of inertia, I, of the molecule 1H35Cl. The masses of the two atoms are mH = 1.673 x 1027 kg and mCl = 5.807 x 1026 kg. The equilibrium bond length of the molecule is 1.275 Å.

. Calculate the position in cm1 of the J = 6 7 line in the pure rotational spectrum of the hydrogen deuteride molecule, HD. The masses of the two atoms are mH = 1.0078 u and mD= 2.0141 u and the equilibrium bond length of the molecule is 0.749 Å.

. The molecule 12C32S has been detected in interstellar clouds using microwave spectroscopy. Predict which rotational level in 12C32S will have the greatest population at a temperature of 70 K. The masses of the two atoms are mC = 12.00 u and mS= 31.972 u and the equilibrium bond length of the molecule is 1.534 Å. Note: The Boltzmann constant, k, has a value in wavenumbers of 0.69503 cm1.

. The first Stokes line and the first anti-Stokes line in the rotational Raman spectrum of N2O are displaced from the Rayleigh line by 2.514 cm1 and + 2.514 cm1, respectively. Determine the rotational constant of N2O.

. Identify which of the following pairs of molecules exhibit both a pure rotational spectrum and a rotational Raman spectrum.

. How many normal modes of vibration are there for C60?

. The force constants of four diatomic molecules are given below.

Which of the four molecules has the highest vibrational wavenumber?

. Which of the following molecules will not display an infrared spectrum?

. For which of the following molecules would you expect the infrared active fundamentals to be Raman inactive and vice versa?

. Which of the following compounds is consistent with an infrared spectrum showing: a broad absorption band at 3000 cm1 with some sharper bands appearing on its shoulder at about 2930 cm1; a strong absorption at about 1700 cm1; a sharp band at 1500 cm1; a series of sharp bands between 650 and 800 cm1?

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