Chlorofluorocarbons CFCs are a class of compounds that contain carbon, chlorine, and fluorine atoms. They were widely used as refrigerants, propellants, and solvents in the past. However, it was discovered that CFCs have a detrimental effect on the Earth's ozone layer, leading to its depletion. The mechanism of how CFCs react with ozone gas in the atmosphere can be explained through the following steps:1. Photodissociation of CFCs: When CFCs are released into the atmosphere, they eventually rise to the stratosphere, where they are exposed to ultraviolet UV radiation. The UV radiation causes the CFC molecules to break apart, releasing chlorine atoms. For example, consider the photodissociation of CFC-12 CCl2F2 : CCl2F2 + UV radiation Cl + CClF2Here, Cl represents a highly reactive chlorine atom with an unpaired electron a free radical .2. Reaction of chlorine radicals with ozone: The chlorine radicals react with ozone O3 molecules, breaking them apart and forming chlorine monoxide ClO and molecular oxygen O2 : Cl + O3 ClO + O2The chlorine radical has effectively destroyed an ozone molecule, converting it into molecular oxygen.3. Reaction of chlorine monoxide with atomic oxygen: The chlorine monoxide ClO radical formed in the previous step can react with atomic oxygen O to regenerate the chlorine radical: ClO + O Cl + O2The regenerated chlorine radical can then go on to react with more ozone molecules, repeating steps 2 and 3. This creates a catalytic cycle in which one chlorine radical can destroy thousands of ozone molecules before it is eventually removed from the atmosphere by other chemical reactions.The overall reaction for the ozone depletion process can be represented as: 2 O3 3 O2This mechanism of CFCs reacting with ozone gas in the atmosphere ultimately leads to the depletion of the ozone layer. The ozone layer plays a crucial role in protecting life on Earth by absorbing harmful UV radiation from the sun. The depletion of the ozone layer allows more UV radiation to reach the Earth's surface, leading to increased risks of skin cancer, cataracts, and other health problems, as well as negative impacts on ecosystems and agriculture.