Chlorofluorocarbons CFCs are compounds containing carbon, chlorine, and fluorine atoms. They were widely used as refrigerants, propellants, and solvents in the past. However, it was discovered that CFCs contribute significantly to the depletion of the ozone layer in the Earth's atmosphere. The ozone layer is crucial for protecting life on Earth from harmful ultraviolet UV radiation.CFCs contribute to ozone depletion through a series of chemical reactions that occur in the stratosphere. When CFCs are released into the atmosphere, they eventually rise to the stratosphere, where they are exposed to UV radiation. This radiation causes the CFC molecules to break apart, releasing highly reactive chlorine atoms.The chemical reactions that lead to the breakdown of ozone by CFCs are as follows:1. Photodissociation of CFCs:CFC + UV radiation CFCl2 + Cl The CFC molecule absorbs UV radiation and releases a reactive chlorine atom 2. Chlorine atom reacts with ozone:Cl + O3 ClO + O2 The reactive chlorine atom reacts with an ozone molecule, forming a chlorine monoxide radical and an oxygen molecule 3. Chlorine monoxide radical reacts with an oxygen atom:ClO + O Cl + O2 The chlorine monoxide radical reacts with an oxygen atom, regenerating the reactive chlorine atom and forming an oxygen molecule 4. The regenerated chlorine atom can then react with another ozone molecule, repeating steps 2 and 3. This cycle can continue, with a single chlorine atom destroying thousands of ozone molecules before it is eventually removed from the stratosphere by other chemical reactions.The overall reaction for ozone depletion by CFCs is:O3 + O 2 O2 Ozone and an oxygen atom react to form two oxygen molecules These reactions lead to a decrease in the concentration of ozone in the stratosphere, resulting in the ozone layer's depletion. This depletion allows more harmful UV radiation to reach the Earth's surface, posing risks to human health and the environment. As a result, the production and use of CFCs have been largely phased out under the Montreal Protocol, an international agreement to protect the ozone layer.