Question

(1) Show with the aid of diagrams the action of each of the following symmetry operations on a point located at (x, y, z). C4 S4 {2 marks}

(2) With reference to a set of character tables, determine the order of each of the following point groups. D2d Oh {2 marks}

(3) Determine the total degeneracy of each of the following irreducible representations ().  = 3Ag + B1u + 2B2u  = A1g + 3Eg + 2T1g + T2u {2 marks}

(4) For each of the following species, sketch the molecule or ion and determine its point group using the flow chart available on Blackboard. In order to secure full marks, you are required to show your answers to each of the questions in the flow chart for each molecule or ion. IF4 + ClF2 + AsF5 N2O4 O3 CS2 trans-[PCl4F2] {7 ×1 mark}

(5) IF5 is square pyramidal (point group C4v). By constructing a suitable basis, corresponding to the I-F stretching vibrations only:

(i) Determine the reducible representation (I-F) for the I-F bond stretching vibrations in IF5. {3 marks}

(ii) Using the reduction formula together with the character table for Td available on blackboard, reduce this representation to its irreducible form. {3 marks} Question continues on next page

(iii) By reference to the character table for Td, determine which of these vibrations are (a) infrared active (b) Raman active. Give reasons for your answer.

Answer 1

here is the answers of questions1and 2.