CH511 Problem Set 2

 

1. A pellet formed from a pure solid powder is attached to 2 electrodes and the electrical conductivity measured at different temperatures. The data obtained are listed below:

T / K σ / Ω-1cm-1
250 2.5 E-4
350 2.7 E-2
450 0.35

        What do you now know about the band structure of this solid? If it is a pure element, which can it be?

 

2.     HF autoionizes to form H2F+(solv) and HF2-(solv). Draw a molecular orbital diagram for the linear bifluoride anion, giving the expected electronic configuration and the bond order. Compare this model with the Lewis structure for the anion.

 

3.    Shriver/Atkins Problem 4.3 (p. 139)

 

4.    Shriver/Atkins Problem 4.5 (p. 139)

 

5.

 

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Discuss the three Pourbaix diagrams above for Ti, Cu, and Au in terms of (1) periodic trends, and (2) the naturally occurring forms of these elements.

6.    Shriver/Atkins Problem 5.9 (p. 168)

7.    Shriver/Atkins Problem 5.12 (p. 168)  In addition, discuss the effect of pH on the stability of permanganate solutions.

8.    Describe the expected 19F NMR spectra for PF2Cl3 and PF3Cl2 at temperatures above and below that required for rearrangement due to a Berry-type mechanism.  Include peak splittings due to F-F and P-F coupling where appropriate.