Name ___________________________
Inorganic Chemistry
Exam 4
April 29, 1997
All work must be shown for any credit to be given.
(3 pts.) 1. Explain why some "forbidden bands" are observed for some coordination ions.
(3 pts.) 2. Give the configuration of the electron in the excited state given the ground state configuration.
__ eg ___ ___
10 Dq =>
__
8 t2g ___ ___ ___2T2g 2Eg
(4 pts.) 3. In terms of ligand exchange, define the terms:
(6 pts.) 4. Give possible geometries for octahedral coordination species for:
(6 pts.) 5. Using the following tables, calculate the number of IR active, the number of Raman active, and the number of inactive bands for NH3.
C3v Character Table
showing the Irreducible Representations for NH3
|
C3v |
E |
2C3 |
3 Fv |
|||
|
A1 |
1 |
1 |
1 |
z |
x2+y2, z2 |
|
|
NH3 |
3 |
12 |
0 |
6 |
||
|
A2 |
1 |
1 |
-1 |
Rz |
||
|
NH3 |
1 |
12 |
0 |
-6 |
||
|
E |
2 |
-1 |
0 |
x,y |
x2-y2, xy |
|
|
NH3 |
4 |
24 |
0 |
0 |
Rx, Ry |
xz, yz |
A1 A2 E
3 1 4 Total spectral terms
- 1 1 2 less rotational and translational
------------------------
vibrational terms
IR-Raman IR-Raman
# IR active bands ___
# Raman active bands ___
# inactive vibration bands ___
(15 pts.) 6. For [V(H2O)6]+2 absorption bands are observed at 12,300, 18,500, and 27,900 cm-1. Assign the bands and calculate or estimate Dq, B’, and the bending.
(5 pts.) 7. Give the rate law expression for the following reaction:
slow
ML6 + L' -----> ML6L'
k
fast
ML6L' ------> ML5L' + L
(4 pts.) 8. For Taube’s "inner sphere" mechanism, give the reaction intermediate for the following reaction:
H+
[Co(NH3)5Cl]+2 + [Cr(H2O)6]+2 ----->[Co(H2O)6]+2 + [Cr(H2O)5Cl]+2 + 5NH4+
H2O
(8 pts.) 9. Give the valence electron counts for the following species. Which one(s) obey the 18-e rule (EAN Rule)?
(5 pts.) 10. Describe what bonds, and how many of each type, are combined to produce a quadruple metal-metal bond.
(2 pts.) 11. The metal in the center of the porphine ring of chlorophylls is ____________________________.
(2 pts.) 12. The metal in the center of the porphine ring of hemeglobin is ____________________________.
(2 pts.) 13. The metal in the center of the porphine ring of Vitamin B12 is ____________________________.
(2 pts.) 14. The metal in questions 11., 12., & 13. are all connected to ________________ atoms of the porphine ring.
(4 pts.) 15. In the respiration cycle, describe how oxygen and carbon dioxide are attached to the hemeglobin molecule.
(6 bonus pts.) 16. In the respiration cycle, oxygen and carob dioxide are exchanged in the cells and in the lungs. These exchanges are both illustrations of LeChatier’s Principle which states that "systems at equilibrium which are disturbed, shift the equilibrium in such a way as to lessen the effect of the stress". Explain what is the "stress" at the cell end of the cycle? What is the "stress" at the lung end of the cycle?
(6 pts.) 17. Describe F. A. Cotton’s explanation for the bonding between Re atoms in ReCl8-2 ion based on the following observations:
(2 pts.) 18. Ammonia is manufactured by the _______________ Process.
(2 pts.) 19. Nitric acid is manufactured by the _________________ Process.
(4 pts.) 20. A very common high explosive is commonly referred to as ANFO, what do the letters stand?
(2 pts.) 21. Give the formula of an oxide of nitrogen which is an air pollutant.
(4 pts.) 22. Give the formula and shape of a halide of phosphorus.
(2 pts.) 23. What is necessary for a compound to be considered organometallic?
(2 pts.) 24. Give an example of a molecule or ion which can act as a B-Donor in an organometallic compound.
(5 pts.) 25. Describe what you have found most useful about this course, lecture or lab.