6.4.10 (HL)—ODS mechanisms

UV breaks down CFCs and other ODSs in the stratosphere, releasing reactive halogens such as chlorine or fluorine; a chlorine radical can destroy many ozone molecules because it is regenerated.

The chlorine radical appears at the start and is regenerated in the second reaction, so it can repeat the cycle until another reaction removes or stores it.

Identify ozone consumption, oxygen production and catalyst regeneration; the net equation excludes the regenerated chlorine radical.

Catalytic loss does not consume one chlorine atom per ozone molecule; the reactive halogen can participate repeatedly.