Problem 1
Draw Lewis structures for ozone and for dioxygen. Using the data given below, qualitatively compare the bond enthalpies, bond orders, and bond lengths of these two compounds. $$ \begin{array}{rr} \mathrm{O}_{2}(g) \rightarrow 20(g) & \Delta H^{\circ}=+498 \mathrm{~kJ} \\ \mathrm{O}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{O}_{3}(g) & \Delta H^{\circ}=-105 \mathrm{kj} \end{array} $$
Problem 2
It has been suggested that the loss of ozone in the stratosphere could lead to a negative feedback which might allow more ozone to be produced. Explain why such a feedback is possible. (This 'self-healing' does in fact, occur, but only to a very small extent.)
Problem 4
A catalyst may be defined as a substance that enhances the rate of a chemical reaction without being consumed in the process. By this definition, a catalyst would have an infinite lifetime. The ozone decomposition catalysts, however, have finite lifetimes. What are possible sinks for removal of the stratospheric catalysts, \(\mathrm{NO}\) and \(\mathrm{Cl}\) ?
Problem 8
A proposal to repair the ozone layer has been made. The suggestion is to inject 'negative charges" into the lower stratosphere, and these would react with CFCs to produce harmless products. From your knowledge of basic chemistry, indicate whether this process would be theoretically possible, and discuss the practical requirements of it. (Chem. Eng. News, May 23. \(1994, p .36\); and Phys. Rev. Lett., 72 (1994), 3124 .
