Additional Problems

1. Write the two-step mechanism by which CO is oxidized to C02. Also include the sequence of reactions by which the hydroperoxy radical so produced oxidizes NO* to NOj, the nitrogen dioxide is photolyzed to NO" and atomic oxygen, and oxygen atoms produce ozone. By adding the steps, show that the atmospheric oxidation of carbon monoxide can increase the ozone concentration by a catalytic process.

2. Using the reactivity principles developed in this chapter, deduce the series of steps and the overall reaction by which ethane, H3C—CHj, is oxidized in the atmosphere. Assume that the aldehydes produced in the mechanism undergo photochemical decomposition to R" and HCO*.

3, When the concentration of nitrogen oxides in a region of the air is very low, peroxy radicals combine with other species rather than oxidize nitric oxide. Deduce the mechanism, including the overall equation, for the process by which carbon monoxide is oxidized to carbon dioxide under these conditions, assuming that the hydroperoxy radicals react with ozone. From your result, would you predict that ozone levels would be abnormally high or low in air masses having low nitrogen oxide concentration? [Hint: See the generalities in the section on the systematics of stratosphere chemistry concerning reactions that produce long oxygen chains.]

4. Predict the most likely reaction (if any) that would occur between a hydroxyl radical and each of the following atmospheric gases: (a) CH3CH2CH3 (b) H2C=CHCH3 (c) HC1 (d) H20

5. Draw complete Lewis structures for N02, HONO, and HN03. (Resonance structures and formal charges are not required.)

6. In Problem 1-2, the longest wavelength of light that could dissociate an O atom from 03 was calculated and determined to occur in the IR region of the spectrum. Using the information in Table 5-1, calculate the longest wavelength of light that could pho-tolytically cleave the loose hydrogen atom in the case of each of the remaining molecules listed in that table. What region of the electromagnetic spectrum does each correspond to?

Coping with Asthma

Coping with Asthma

If you suffer with asthma, you will no doubt be familiar with the uncomfortable sensations as your bronchial tubes begin to narrow and your muscles around them start to tighten. A sticky mucus known as phlegm begins to produce and increase within your bronchial tubes and you begin to wheeze, cough and struggle to breathe.

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