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. Select the correct statement:

Some of the most important symmetry operations include: identity, mirror plane, center of inversion, n-fold rotation, and reflection. correct incorrect

Some of the most important symmetry operations include: identity, n-fold rotation, reflection, inversion, and n-fold rotation with reflection in a plane perpendicular to the rotation axis. correct incorrect

Some of the most important symmetry operations include: n-fold symmetry axis, "whole of space," mirror plane, center of inversion, and n-fold axis of improper rotation. correct incorrect

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. What is the point group of linear molecules with a centre of symmetry?

D_∞h correct incorrect

C_∞h correct incorrect

T_d correct incorrect

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. Phosphorus pentachloride, PCl₅ is a trigonal bipyramidal molecule. To what point group does it belong?

D_3v correct incorrect

D_3h correct incorrect

C_3h correct incorrect

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. What are the point groups of tetrahedral and octahedral molecules?

D_3h and D_4h respectively correct incorrect

C_3h and C_4h respectively correct incorrect

T_d and O_h, respectively correct incorrect

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. Select the correct statement:

The character tables list short-hand symbols for all symmetry-allowed point groups and provide the key to help assign any given molecule to the proper point group correct incorrect

The character tables provide the transformation matrices for each symmetry element together with the final result of the transformation correct incorrect

The character tables contain all the symmetry elements for a given point group as well as a description of how objects transform under the corresponding symmetry operations. correct incorrect

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. A molecule cannot be polar if:

It has a centre of inversion. correct incorrect

It has no centre of inversion. correct incorrect

Its dipole moment lies perpendicular to any mirror plane or rotation axis of the molecule. correct incorrect

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. If a molecule possesses an improper rotation axis (S_n), then chirality is:

implied correct incorrect

ruled out correct incorrect

Chirality of a molecule has nothing to do with any type of molecular symmetry. correct incorrect

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. The exclusion rule states that:

If a molecule has a centre of inversion, then all of its modes can be both IR and Raman active. correct incorrect

If a molecule has a centre of inversion, then some of its modes can be both IR and Raman active. correct incorrect

If a molecule has a centre of inversion, then none of its modes can be both IR and Raman active. correct incorrect

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. When is a vibrational mode of a molecule IR active?

when the vibrational mode has the same symmetry as a component of the molecule's electric dipole moment vector correct incorrect

when the vibrational mode has the same symmetry as a component of the molecule's polarizability correct incorrect

vibrational modes of molecules are Raman active only; they cannot be IR active at the same time correct incorrect

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. The molecule of the chemotherapeutic drug PdCl₂(NH₃)₂ is square planar, with two isomers: cis-(C_2v symmetrical) and trans-(D_2h symmetrical). Select the statement that applies:

The cis-isomer's Raman and IR spectra both show two bands in the Pd-Cl stretching region; the trans-isomer's IR and Raman spectra show only one band at different frequencies for each. correct incorrect

The cis-isomer's Raman and IR spectra show only one band at different frequencies for each; the trans-isomer's IR and Raman spectra both show two bands in the Pd-Cl stretching region. correct incorrect

Cis- and trans-isomers of the compound are not distinguishable by Raman or IR spectroscopy. correct incorrect