How does CFC deplete Ozone layer?
CFC ( chloro fluro carbon ) when mixed in atmosphere travels to upper atmosphere and gets disassociated generating highly reactive chlorine atoms which alter the bidirectional reaction of ozone formation.
Natural step:
O3 <----------> O2 + O
release of CFC:
CCl2F2 -----------------> CClF2 + Cl-
depleting reaction:
O3 + Cl- -----------> ClO- + O2
ClO + O3 ---------> ClO2 + O2