Question

When two or more refrigerants are mixed?

Answer 1

Hint: A refrigerant is a chemical substance that is used to transfer heat from one area to another area in a heat cycle. Also, when mixtures of the same substances i.e. same concentration of vapour and fluid phases are formed, it forms an azeotropic mixture.

Complete answer:
A refrigerant is a chemical substance that is used to transfer heat from one area to another area in a heat cycle. It basically acts as a heat carrier. It is commonly used in fridges, air conditioners, freezers etc.
When two or more refrigerants are mixed into each other, it forms an azeotropic mixture. Let us first understand about the azeotropic mixtures.
An azeotropic mixture is formed when the substances that are mixed with each other have the same concentration of vapour and fluid phases. Basically, it is a mixture that contains two or more liquids. Azeotropic mixture has constant or same boiling points and the mixture’s vapour will also have the same composition as the liquid.
In an azeotropic mixture the vapour and fluid concentration will be the same which will prevent their separation. Azeotropic mixtures show deviation from Raoult’s law.
Therefore, mixing of two or more refrigerants results in the formation of the Azeotropic mixtures. Azeotropic refrigerants are mixtures of two or more components that boil at the same temperature.

Note:
Earlier, chlorofluorocarbons (CFC’s) were used as refrigerants but now they are banned because of their ozone depleting effects. There are some common refrigerants such as ammonia, sulphur dioxide and non- halogenated hydrocarbons such as propane. Most refrigerants found at the end of life devices can cause ozone depletion and global warming.