Refrigerants

Refrigerants are substances that are used in refrigeration systems to transfer heat from one location to another. They undergo a phase change from a gas to a liquid and back to a gas during the refrigeration cycle. The choice of refrigerant is crucial as it directly affects the efficiency and environmental impact of the refrigeration system.

Chlorofluorocarbons (CFCs)

Chlorofluorocarbons (CFCs) were widely used as refrigerants in the past due to their desirable properties such as low toxicity, non-flammability, and stability. However, it was later discovered that CFCs contribute to the depletion of the ozone layer in the Earth's atmosphere. The production and use of CFCs have been phased out under the Montreal Protocol due to their harmful effects on the ozone layer.

Hydrochlorofluorocarbons (HCFCs)

Hydrochlorofluorocarbons (HCFCs) were developed as alternatives to CFCs. They have a lower ozone depletion potential (ODP) compared to CFCs but still contribute to the depletion of the ozone layer. HCFCs are being phased out globally under the Montreal Protocol.

Hydrofluorocarbons (HFCs)

Hydrofluorocarbons (HFCs) are the most common refrigerants used today. They do not contain chlorine and therefore do not deplete the ozone layer. HFCs have a high global warming potential (GWP), meaning they contribute to climate change. However, they are considered a temporary solution as they have a lower GWP compared to CFCs and HCFCs.

Correct Answer

The correct answer to the given question is option 'D' - CClF (also known as CFC-11). This compound is a chlorofluorocarbon (CFC) that was once widely used as a refrigerant. However, its production and use have been phased out due to its harmful effects on the ozone layer.

In summary, the compound used as a refrigerant is CClF (CFC-11). However, it is important to note that the production and use of CFCs have been phased out due to their harmful effects on the ozone layer.