Which type of refrigerant is the most harmful to stratospheric ozone?

• A. Ammonia (NH3)
• B. Hydrofluorocarbons (HFCs)
• C. Chlorofluorocarbons (CFCs)
• D. Hydrochlorofluorocarbons (HCFCs)

Answer: (C)

Verified step by step guidance

1. Understand the role of refrigerants in atmospheric chemistry, particularly their impact on the stratospheric ozone layer.
2. Recall that Chlorofluorocarbons (CFCs) contain chlorine atoms, which are released in the stratosphere and catalyze the breakdown of ozone (O3) molecules.
3. Recognize that ammonia (NH3) does not contain halogens and thus does not contribute to ozone depletion.
4. Note that Hydrofluorocarbons (HFCs) and Hydrochlorofluorocarbons (HCFCs) have less or no chlorine content, making them less harmful to ozone compared to CFCs.
5. Conclude that among the given options, CFCs are the most harmful to stratospheric ozone due to their chlorine content and their ability to catalyze ozone destruction.