Which liquid is used as a refrigerant in refrigerators?

Correct option is B

Fluorocarbons (CFCs, HCFCs, and HFCs) have been widely used as refrigerants in household and industrial refrigerators and air conditioners. These compounds are preferred because they are chemically stable, non-toxic, and have low boiling points, making them effective for heat absorption and cooling.

Earlier, CFCs (Chlorofluorocarbons) like Freon-12 (CCl₂F₂) were commonly used, but they were phased out due to their ozone-depleting potential. Currently, HFCs (Hydrofluorocarbons) like R-134a (Tetrafluoroethane, C₂H₂F₄) are used as environmentally safer alternatives.

Information Booster

• Primary Refrigerants Used Today: HFCs like R-134a, R-410A.
• Why Fluorocarbons?
  • Non-toxic and non-flammable.
  • Efficient heat absorption at low pressures.
  • Chemically stable under refrigeration conditions.
• Environmental Impact:
  • CFCs and HCFCs deplete the ozone layer.
  • HFCs have a lower environmental impact but contribute to global warming.
• Alternative Green Refrigerants:
  • Ammonia (NH₃) – Used in industrial refrigeration.
  • Carbon dioxide (CO₂) – Being explored as an eco-friendly option.

Additional Knowledge

• (a) Carbon dioxide – Incorrect. CO₂ is used in some commercial refrigeration systems but is not common in household refrigerators.
• (b) Fluorocarbons – Correct. CFCs, HCFCs, and HFCs have been used as refrigerants due to their stability and cooling efficiency.
• (c) Ammonia – Incorrect. Ammonia (NH₃) is used in industrial refrigeration but is toxic and unsuitable for household refrigerators.
• (d) Oxygen – Incorrect. Oxygen is not used as a refrigerant due to its high reactivity and flammability.