Which statement regarding the mechanism and species involved in the depletion of the ozone layer by chlorofluorocarbons (CFCs) in the stratosphere is correct?
The initiation step of ozone depletion involves the homolytic fission of a C−Cl\text{C}-\text{Cl}C−Cl bond in a CFC molecule by the absorption of high-energy infrared radiation.
The C−F\text{C}-\text{F}C−F bond in a chlorofluorocarbon molecule undergoes homolytic fission more readily than the C−Cl\text{C}-\text{Cl}C−Cl bond because fluorine is more electronegative than chlorine.
In the catalytic cycle of ozone depletion, the chlorine radical (Cl∙\text{Cl}^\bulletCl∙) acts as a homogeneous catalyst, being consumed in the first propagation step and regenerated in the second.
A single chlorine radical can destroy thousands of ozone molecules because it is regenerated during a termination step of the chain mechanism.
25 exam-style questions on AQA A Level Chemistry Halogenoalkanes, covering Nucleophilic substitution, Elimination, and Ozone depletion. Each one has a worked solution and a mark scheme showing where the marks go.