Q.What are Freons? Discuss their uses and environmental effects.

Step 1. Identity. Freons (CFCs) are the chlorofluoro derivatives of methane and ethane, named by the Freon-cba code (e.g. Freon-12 = CCl2F2, made from CCl4 + HF via the Swarts reaction).

Step 2. Properties. They are highly stable, chemically unreactive, non-corrosive, non-toxic, and easily liquefiable -- an unusually convenient combination of properties for handling as a working fluid.

Step 3. Uses. Precisely because of those properties, Freons became the dominant 20th-century refrigerant in refrigerators and air conditioners, and the standard propellant gas for aerosol sprays and foams (deodorants, shaving creams, insecticide sprays). …

Give the definition and naming code briefly, list the properties that explain the uses, then connect that SAME stability property directly to the ozone-depletion environmental effec …

• Describing the environmental harm vaguely as 'pollution' without naming the specific ozone-depletion mechanism -- the unit's own framing (poly halogen compounds are useful but pose 'environmental threat') is mad …