Question

Give method of preparation, properties and uses of Freon.

Answer 1

Hint: Try to recall that Freons are the chlorofluoro compounds of methane and ethane and are extremely stable under high pressures and temperatures. They are also responsible for the depletion of the ozone layer. Now, by using this you can easily answer the given questions.

Complete step by step solution:
It is known to you that the chloro fluoro compounds of methane and ethane are collectively known as freons.

Properties of freons are as follows:
They are extremely stable and highly unreactive compounds.
They have low boiling points and are non-inflammable.
They are non-toxic, non-corrosive and are easily liquefiable.
They are stable even at high temperature and pressure.
Out of all of them, dichlorofluoromethane (\[CC{l_2}{F_2}\]) known as Freon-12 is the most important compound of this class because of its industrial use.
It is manufactured by the action of antimony fluoride on carbon tetrachloride in the presence of antimony pentachloride by Swarts reaction. The reaction is:
\[3CC{l_4} + 2Sb{F_5}\xrightarrow{{SbC{l_5}}}2SbC{l_5} + 3CC{l_2}{F_2}\]
Alternatively, Freon-12 is also prepared by the action of hydrogen fluoride on carbon tetrachloride in carbon and ferric chloride. The reaction is:
\[CC{l_4} + 2HF\xrightarrow{{C,FeC{l_3}}}2HCl + CC{l_2}{F_2}\]
Uses of freons are as follows:
Freons are used as refrigerants in refrigerators and air conditioners.
They are also used extensively as propellants for aerosols and foams.

Note: It should be remembered to you that freons are persistent because microorganisms and other agents that cause biodegradation of organic materials are unable to break these extremely stable molecules and due to this the use of freons as propellants and refrigerants has been drastically discouraged and banned in many countries.