Chlorine atoms generated photochemically from chlorofluorocarbons (CFCs) are known to accelerate the decomposition of stratospheric ozone according to the overall reaction
2O3(g)⟶3O2(g)
Scientists observe that the presence of trace quantities of Cl(g) radicals leads to a dramatic increase in the rate of ozone loss without an accompanying net consumption of chlorine.
(a) Describe two essential characteristics that must be satisfied for Cl(g) to be classified as a catalyst in this reaction.
(b) Explain, in terms of reaction‐coordinate diagrams, how the introduction of the chlorine‐involving pathway alters the activation energy compared with the uncatalyzed decomposition.
(c) Provide a verbal explanation, at the particulate level, of why the formation of a transient intermediate can allow the catalyzed pathway to proceed more rapidly even though the stoichiometry of the overall reaction is unchanged.