Problems

1. What is the lifetime of CI, with respect to conversion into HCl and ClONO ,? Over these lifetimes, how many O, molecules does a CI, molecule destroy? Express your answer in terms of rate constants and concentrations.

2. Imagine that ./ri()NOi suddenly increases. Describe qualitatively what would happen to the abundance of HC1 in the lower and upper stratosphere?

3. HOCI is generally a minor component of the Clv family. Consider the following reactions involving HOCI:

(a) Assume the photochemical steady state. Write an expression for [Cl,]/[HOCl]. Make any assumptions that you make explicitly clear.

(b) The loss lifetime of HOCI (1/L) is about an hour. Is this system in the strict photochemical steady state where production equals loss at all times? Explicitly state what time constants you are comparing and their approximate magnitudes.

4. Assume that the NO, family is in photochemical steady state. Write an expression for [NOJ/IHNOj] (in terms of rate constants, photolysis frequencies, and the abundance of other species) assuming gas-phase-only reactions. How does the hydrolysis of N2Os affect the partitioning?

5. Ozone loss from Br0N02 photolysis. Consider the following bromine reactions:

Given these reactions, show that if BrONO, photolyzes to form Br and NO, then this will lead to a catalytic odd-oxygen loss cycle, but if the photolysis products are BrO and NO,, then no net loss occurs. Feel free to include other reactions discussed in this chapter.

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