CHEM 342. Spring 2002.  Next PS   Previous PS  Answers  PS#7.doc (Word97)  

Problem Set #7

Note: Relevant sections in Mortimer are Chapter 18 and Appendix I.

For the problems #1-14, please list the Schoenflies symbols and symmetry elements for each of the following molecules. State whether or not each molecule is optically active; and also state whether or not it has a permanent dipole moment. Hint: The Schoenflies symbols and have the symmetry elements and respectively.

1.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

2.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

3.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

4.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

5.

1,3,5-tribromobenzene

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

6.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

7.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

8.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

9.

p-dichlorobenzene

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

10.

cyclohexane

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

11.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

12.

CO

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

13.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

14.

Schoenflies symbol:

Symmetry elements:

Optically Active: Yes or No

Permanent Dipole Moment: Yes or No

15. State if a orbital is symmetric or anti-symmetric with respect to the following operations

1. reflection across the xy plane
2. reflection across the xz plane
3. reflection across the yz plane
4. operation
5. operation
6. inversion (i) operation
7. rotation about the x-axis

16. State if a orbital is symmetric or anti-symmetric with respect to the following operations

1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. inversion, i

17. Which, if any, of the following point groups have a permanent dipole moment?

18. Which, if any, of the following point groups show optical activity?

• The work you hand in should be neat and well organized, and it should show the strategy and steps you used in solving the problems, as well as the bottom-line answers (or solutions). In grading the problems, both your work-up and your final answers/solutions will be examined and evaluated.
• The work handed in for grading must carry a pledge that the work is entirely yours and was done without any collaboration with other persons (except for the course instructor and TA's). You are encouraged to work with others in doing the exercises and problems found in the textbook, but all work handed in for grading should be done independently.