Chlorofluorocarbons CFCs are compounds containing chlorine, fluorine, and carbon atoms. They were widely used as refrigerants, propellants, and solvents before their harmful effects on the ozone layer were discovered. The chemical reaction between CFCs and ozone that leads to ozone depletion can be described in a series of steps:1. Photodissociation of CFCs: When CFCs reach the stratosphere, they are exposed to ultraviolet UV radiation, which causes them to break down and release chlorine atoms. For example, when CFC-12 CCl2F2 undergoes photodissociation, it forms a chlorine atom and a chlorodifluoromethyl radical: CCl2F2 + UV Cl + CClF22. Chlorine atom reacts with ozone: The released chlorine atom reacts with an ozone O3 molecule, forming a chlorine monoxide ClO radical and an oxygen molecule O2 : Cl + O3 ClO + O23. Chlorine monoxide reacts with an oxygen atom: The ClO radical reacts with an oxygen atom O , which is formed by the photodissociation of ozone, to regenerate the chlorine atom and produce an oxygen molecule: ClO + O Cl + O24. Regeneration of chlorine atoms: The chlorine atom from step 3 can then react with another ozone molecule, repeating steps 2 and 3. This cycle can continue thousands of times, leading to significant ozone depletion.Overall, the net reaction can be represented as: 2 O3 3 O2This shows that two ozone molecules are converted into three oxygen molecules, leading to a decrease in the concentration of ozone in the stratosphere.