Open book and open notes.
October 5, 2000
1. Write the electron configurations for the following (use the rare gas notation for closed shells): a) Gd3+; b) Rh3+; c) Os3+; d) Tl3+; e) Bi3+. Answer.
2. Find all of the Russell-Saunders and J terms for the f1 electron configuration. Predict the energetic ordering of the different states. Answer.
3. Calculate Z* for the highest energy electron in the following ions: K+, Ca+, Sc+, Ti+, V+. Does Z* account for the observed values of the second ionization potential of these elements? (see Table 1.7). Why or why not? Some have argued that Ca+ should be considered a transition metal. Give an argument to support this contention. Answer.
4. Consider the following two compounds: CF2C(F)CN (having
a C-C-C backbone) and CF2C(F)NC (having a C-C-N backbone). Write
the lowest energy Lewis structures for each, give the formal charge and
oxidation number for each atom, estimate the bond lengths for each bond
and bond angles for each atom along the backbone, and indicate the likely
hybridization at each atom along the backbone. In addition to the information
in Table 2.8, the following may be of use:
| bond | typical bond length (Å) |
| C=C |
|
| C=C |
|
| C=N |
|
| C=N |
|
5. Consider the molecule formed by the reaction of SO2 and NH3 (analogous to the example of sulfamic acid discussed in class). Predict the structure and bonding properties of the reaction product. Answer.