Q.Which aerosols deplete ozone?

Step 1: Identify the aerosols.

Chlorofluorocarbons (CFCs), commonly called freons (e.g. $CCl_2F_2$, $CCl_3F$), were widely used as aerosol propellants, refrigerants and in air-conditioning systems.

Step 2: Mechanism of ozone depletion.

When released into the atmosphere, CFCs slowly diffuse up to the stratosphere, where intense UV radiation breaks the C–Cl bond to release chlorine free radicals:

Step 3: Catalytic destruction of ozone.

The chlorine radical then catalytically destroys ozone in a chain reaction:

$ClO^{\bullet} + O \rightarrow Cl^{\bullet} + O_2$ …

Name the responsible aerosols (CFCs/freons), and briefly show the catalytic radical-chain mechanism by which chlorin …

• Do not name CO₂ or generic "greenhouse gases" — those relate to global warming, a distinct issue from ozone-layer depletion.
• Do not forget the chlorine radical is a catalyst (regenerated at the end of the cycle) — this is why even trace amounts of CFCs cause disproportionately large ozone destruction, and is the key mechanistic point. …