JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ev102
Which statements about the fate of CFCs are correct?
AThey are very stable towards chemical attack in the troposphere.
BIn the stratosphere short-wavelength UV photolyses them to release chlorine atoms.
CThey are washed out of the atmosphere by rain within days.
DThe first photolysis step breaks the C-F bond to release fluorine atoms.
Answer: A, B
CFCs are inert and water-insoluble, so rain does not remove them and they reach the stratosphere. There UV breaks the weaker C-Cl bond, releasing Cl. The C-F bond is far stronger and is not the first bond broken.