The gas-phase oxidation of carbon monoxide by nitrogen dioxide proceeds according to the overall reaction
NO2+CO→NO+CO2.
Experimental studies reveal the rate law rate=k[NO2][CO] at temperatures below 600 K. A trace amount of chlorine gas is found to accelerate the reaction without being consumed.
(a) Propose a mechanism containing no more than three elementary steps that (i) reproduces the observed rate law, (ii) includes Cl2 as a catalyst that is fully regenerated, and (iii) contains only uni- or bimolecular elementary steps.
(b) Show explicitly that summing the elementary steps you proposed in part (a) regenerates Cl2 and yields the overall balanced reaction.
(c) Derive the rate law predicted by your mechanism, clearly stating any steady-state or rate-determining assumptions used. Demonstrate that the derived rate law simplifies to rate=k[NO2][CO].
(d) Design an experiment that would distinguish between your chlorine-catalyzed mechanism and an alternative mechanism that does not involve Cl2. Describe the data you would collect and the criterion you would use to favor one mechanism over the other.