Chemical formula of Freons :

How many $\mathrm{\sigma }$ and $\mathrm{\pi }$ bonds are present in the structure of D.D.T respectively?

Give one use of Feron.

Note: The question given in the book seems to have error and the modified question should be as given below:

Give one use of Freon.

In the following sequence of reactions, the gaseous species $\mathrm{A}\text{,} \mathrm{B}\text{,} \mathrm{D}\text{,} \mathrm{E}$, respectively, are