(Flame retardants) Hydrogen radicals are important to sustaining combustion reactions. Con...

(Flame retardants) Hydrogen radicals are important to sustaining combustion reactions. Consequently, if chemical compounds that can scavenge the hydrogen radicals are introduced, the flames can be extinguished. While many reactions occur during the combustion process, we shall choose CO flames as a model system to illustrate the process [S. Senkan et al., Combustion and Flame, 69, 113 (1987)]. In the absence of inhibitors

The last two reactions are rapid compared to the first two. When HCl is introduced to the flame, the following additional reactions occur:

Assume that all reactions are elementary and that the PSSH holds for the O., OH., and CI - radicals.

(a) Derive a rate law for the consumption of CO when no retardant is present.

(b) Derive an equation for the concentration of H- as a function of time assuming constant concentration of O2, CO, and H2O for both uninhibited combustion and combustion with HCl present. Sketch H- versus time for both cases.

(c) Sketch a reaction pathway diagram for this reaction.

(d) List ways you can work this problem incorrectly.

(e) How could you make this problem more difficult?

More elaborate forms of this problem can be found in Chapter 6, where the PSSH is not invoked.