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There, the sun’s radiation would break the molecules apart, and the chlorine atoms would act as a catalyst, breaking apart ozone atoms. In fact, one chlorine atom could destroy about 100,000 ...
Chlorofluorocarbons (CFCs): when derived from methane and ethane these compounds have the formulae CCl m F 4−m and C 2 Cl m F 6−m, where m is nonzero. Hydro-chlorofluorocarbons (HCFCs): when derived from methane and ethane these compounds have the formula CCl m F n H 4−m−n and C 2 Cl x F y H 6−x−y, where m, n, x, and y are nonzero.
2 molecules to create two O 3 molecules. These ozone molecules absorb UVB light, following which ozone splits into a molecule of O 2 and an oxygen atom. The oxygen atom then joins up with an oxygen molecule to regenerate ozone. This is a continuing process that terminates when an oxygen atom recombines with an ozone molecule to make two O 2 ...
Because the concentration of CFCs in atmosphere is very low, the probability of a terminating reaction is exceedingly low, meaning each radical can decompose many thousands of molecules of ozone. Even though the use of CFCs has been banned in many countries, CFCs can stay in the atmosphere for 50 to 500 years. This causes many chlorine radicals ...
The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. Chlorodifluoromethane (R-22), for example, has an ODP of 0.05. CFC 11, or R-11 has the maximum potential amongst chlorocarbons because of the ...
Ozone in the troposhere is determined by photochemical production and destruction, dry deposition and cross-tropopause transport of ozone from the stratosphere. [2] In the Arctic troposphere, transport and photochemical reactions involving nitrogen oxides and volatile organic compounds (VOCs) as a result of human emissions also produce ozone resulting in a background mixing ratio of 30 to 50 ...
In the upper atmosphere, the photodissociation of normally unreactive chlorofluorocarbons (CFCs) by solar ultraviolet radiation is an important source of radicals (see eq. 1 below). These reactions give the chlorine radical, Cl •, which catalyzes the conversion of ozone to O 2, thus facilitating ozone depletion (eq. 2.2–eq. 2.4 below).
CFCs have potent ozone depletion potential due to the homolytic cleavage of the carbon-chlorine bonds; their use is largely prohibited by the Montreal Protocol. Hydrofluorocarbons (HFCs), such as tetrafluoroethane, serve as CFC replacements because they do not catalyze ozone depletion.