- 2070 Bhadra · 2 marks
CFCs in ozone depletion and harmful effects
Short answer
CFC-11 (CCl₃F) and CFC-12 (CCl₂F₂) release chlorine atoms under UV radiation, catalytically destroying ozone. Harmful effects include increased UV-B causing skin cancer, cataracts, reduced crop yields, death of phytoplankton, and degradation of plastics and paints.
Write the CFC involved for ozone layer depletion and harmful effects.
CFCs involved
The CFCs mainly responsible are CCl₃F (CFC-11), CCl₂F₂ (CFC-12), and also CCl₂FCClF₂ (CFC-113). In the stratosphere UV breaks them to give chlorine atoms, which destroy ozone catalytically:
CCl₂F₂ + hν → •CClF₂ + Cl•; Cl• + O₃ → ClO• + O₂; ClO• + O → Cl• + O₂
Harmful effects of ozone depletion
- Increased UV-B reaching the earth causes skin cancer, sunburn, cataract and weakening of the immune system.
- Damages crops and forests, reducing yield.
- Kills phytoplankton and other aquatic organisms, upsetting the marine food chain.
- Degrades plastics and paints; increases ground-level ozone and smog.
- Contributes to global warming (CFCs are greenhouse gases).
✓ Answer checked by Claude Opus 5.5 (high effort)
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