Critical Temperature of Refrigerants

The critical temperature of a refrigerant is the temperature above which the refrigerant cannot be liquefied, no matter how much pressure is applied to it. It is an important parameter to consider when selecting a refrigerant for a particular application.

Refrigerants and their Critical Temperatures

a) Water: Water has the highest critical temperature among the given options. Its critical temperature is 374°C. Due to its high critical temperature, water is not suitable for use in most refrigeration and air conditioning applications.

b) Carbon dioxide: Carbon dioxide has a critical temperature of 31°C. It is commonly used as a refrigerant in low-temperature applications, such as in food processing and storage.

c) Freon 12: Freon 12, also known as dichlorodifluoromethane, has a critical temperature of 111.4°C. It was widely used as a refrigerant in the past, but its production and use have been phased out due to its harmful effects on the environment.

d) Ammonia: Ammonia has a critical temperature of 132.4°C. It is commonly used as a refrigerant in industrial applications, such as in large refrigeration systems for food processing and storage.

Conclusion

Water has the highest critical temperature among the given options, making it unsuitable for most refrigeration and air conditioning applications. Carbon dioxide, Freon 12, and ammonia have lower critical temperatures and are commonly used as refrigerants in various applications.