Question

Freon used as refrigerant is:
A) $\text{CF}_2=\text{CF}_2$
B) $\text{CH}_2\text{F}_2$
C) $\text{CCl}_2\text{F}_2$
D) $\text{CF}_4$

Answer 1

Hint: We know that the compounds of carbon which contain more than one halogen atom are referred to as polyhalogen compounds. These compounds have many industrial and agricultural applications.

Complete answer:
We can say that the chlorofluoro compounds of methane and ethane in which all the hydrogen atoms are replaced by the halogen atoms are collectively regarded as freons.
We can classify freons on the basis of the number of fluorine atoms present in them. There examples of freons are $\text{CF}_4$ named as Freon-14, $\text{CCl}\text{F}_3$ named as Freon-13, $\text{CCl}_2\text{F}_2$ named as Freon-12 and $\text{CCl}_3\text{F}$ named as Freon-11. From all these classes the one which is used as a refrigerant is Freon-12 which has the chemical formula $\text{CCl}_2\text{F}_2$.

Hence, we can conclude that the correct option is C.

Note: We know that the Freon is the odorless, non-corrosive and non-toxic gas which is also stable at high values of temperature and pressures. It has low boiling point and also has low specific heat that’s why it is easily liquefied by the action of pressure at temperature equal to the room temperature. It is also known that it has an adverse effect on the environment as it initiates the radical chain reactions which can disrupt the natural ozone balance.