Question

3.3. The chlorofluorocarbon CFC-12 (CF2Cl2) is removed from the atmosphere solely by photolysis. Its atmospheric lifetime is 100 years. In the early 1980s, before the Montreal protocol began controlling production of CFCs because of their effects on the ozone layer, the mean atmospheric concentration of CFC-12 was 400 pply and increased at the rate of 4% per year. What was the CFC-12 emission rate during that period? [10

Answer 1

Answer We know that Chlorofluorocarbon CFC-12 (CF2CL₂) was a commonly used refrigerant and aersol spray propellant. By using Global mass balance equation for CFC -12. is Im = E - km f here ma Er atmospheric mass of CFC-12 Emission rate k=44 2010%ým photolysis constant as given So from the above egne Relative accumulation rate (ym) do 15 47.fgen or 0.04 year.

Atmospheric mass of CFC-12 'm'- MCF CC FC No = 6 - 18 x0 x 6-11 xt. В хоо = 3-5 ко" - By. Substituting the values weget Е= 6-оҷ Fo-o1 ) - ко" (ce - e-t) Е: -2 ко" әлем