ADVANCED INORGANIC CHEMISTRY Quiz 2 October 8, 2008 INSTRUCTIONS by GeorgeWhitelock

VIEWS: 19 PAGES: 5

									ADVANCED INORGANIC CHEMISTRY                            Quiz 2
                      October 8, 2008
INSTRUCTIONS:
     PRINT YOUR NAME ————> NAME         ___________________           .


WORK all 5 problems
TOTAL = 100


SHOW YOUR WORK FOR PARTIAL CREDIT


USE THE CORRECT NUMBER OF SIGNIFICANT FIGURES

THE LAST PAGE ARE A PERIODIC TABLE


R = 0.08206 lit-atm/mol-K                               1        20
R = 8.3145 J/mol-K                                      2        15
h = 6.626 X 10-34 J-s                                   3        15
c = 2.9979 X 108 m/s                                    4        20
                                                        5        30
         2      2
J = (kg-m )/s
                                                TOTAL(100)
1. Using Slater’s Rules for calculating S listed below:

1.     The electronic structure of the atom is written in groupings as follows:
       (1s) (2s, 2p) (3s, 3p) (3d) (4s, 4p) (4d) (4f) (5s, 5p), and so on.

2.     Electrons in higher orbitals (to the right in the list above) do not shield those in
       lower orbitals.

3.     For ns or np valence electrons:
              a.      Electrons in the same ns, np level contribute 0.35, except the 1s,
                      where 0.30 works better.
              b.      Electrons in the n-1 level contribute 0.85.
              c.      Electrons in the n-2 or lower levels contribute 1.00.

4.     For nd and nf valence electrons:
              a.      Electrons in the same nd or nf level contribute 0.35.
              b.      Electrons in groupings to the left contribute 1.00.

(a) Define Z* and S and explain the significance of Z* with respect to the energy of an
electron.




(b) Calculate Z* for a 2p electron in Mn.




(c) Calculate Z* for a 3d electron in Mn




(d) One of the values of Z* that you calculated in (b) or (c) is larger. Explain why.
2. Answer the following questions.

(a) Why is a the atomic radius of a S atom bigger than an O atom? (the answer is not S is
below O in the periodic table.)




(b) Rank the following in order of ionization energy N , O , O+, and P.

______< _______ < ______ < _______


(c) Explain why the following compound is unlikely to form: CaCl3




(d) Place the following molecules or ions in increasing order of the magnitude of the
property in the left-hand column.

Radius                S2-   Cl-      K+      ______ < _______ < _________

Ionization energy     Co+ Co2+ Co3+          ______ < _______ < _________

Radius                Si     S       Sn      ______ < _______ < _________

Ionization Energy     Si     S       Sn     ______ < _______ < _________

Radius                O2-     O      O+      ______ < _______ < _________

(e)
3. Consider the sulfite ion, SO32-
(a) Draw a valid Lewis structure for this ion that obeys the octet rule and assign formal
charges to each atom.




(b) Draw a valid Lewis structure for this ion that has more reasonable formal charges
and assign formal charges to each atom.




(c) Draw the resonance structures for the structure that you drew in (b).




(d) What shape is the sulfite ion?




(e) Predict the O-S-O angle in the sulfite ion.
4. Draw a valid Lewis structure for the following molecules or ions. Include formal
charges to each atom in (b), and (f). (The central atom is listed first except for (f))

(a) PCl3                             (b) AsF4–                      (c) SOF2




(d) XeO3                             (e) BrF5                       (f) SCN-
                                                                    (C atom central)




5. Draw a valid Lewis structure and determine shape of the following molecules using
VSEPR. Assign formal charges in (a) and (b). For neutral species (c), (d), (e), and (f),
assume all bonds in are polar, and determine whether the molecule is polar.
(The central atom is listed first.)

(a) PF6-                                     (b) XeCl3+                           (c)POCl




(d) PF5                                      (e) XeO2Cl4                           (f)SO2

								
To top