16.3 Uses of Halogenoalkanes
The use of CFCs
- CFCs are chlorofluorocarbons, compounds containing carbon with chlorine and fluorine atoms attached. Two common CFCs are CFC-11(CCl3F) and CFC-12(CCl2F2).
- Some properties and uses of CFCs:
CFCs and the environment
- CFCs have many uses in our daily life. However, due to their stability and inertness, they are also large responsible for the destruction of the ozone layer. Ozone layer prevents harmful ultraviolet radiation from reaching us
- Destruction of the ozone layer involves the conversion of ozone molecule, O3 to oxygen molecule, O2. The detailed mechanism is as shown below:
- Possible solutions to protect the ozone layer:
- Reduce the use of CFCs. For example, replace aerosol spray with manual pump spray
- Collect and recycle CFCs for future use
- Find alternatives for CFCs
- Possible alternatives for CFCs:
- Use HCFCs(CFCs with at least one hydrogen atom, for example, CF3CHCl2)
- HCFCs have smaller effect on ozone depletion because they are more readily destroyed in the troposphere
- However, a disadvantage of using it is, it is flammable. Also, it could potentially form toxic chemicals in the troposphere
- Use LPG(liquid petroleum gas) as propellant in aerosol sprays
- Use air-blowing agent in packaging and building industries
- Use water-based cleaning system in electronic industries
- Use HCFCs(CFCs with at least one hydrogen atom, for example, CF3CHCl2)