Question

A. Teflon has high thermal stability and chemical inertness.
 R. Teflon is a thermoplastic.
1) Both A and R are correct and R is the correct explanation of A
2) Both A and R are correct and R is not the correct explanation of A
3) A is correct but R is incorrect
4) A is incorrect but R is correct

Answer 1

Hint: A thermoplastic is a material, usually a plastic polymer, which becomes soft when heated and hard when cooled. These materials can be cooled and heated several times without creating any change in their properties.

Complete solution:
Teflon or polytetrafluoroethylene (PTFE) is a type of synthetic polymer which is prepared by free radical addition polymerization and has a brand name of chemical coating.
Teflon comes under the category of thermoplastic which provides it to be cooled and heated several number of times without causing any structural or chemical change in it
Teflon is known for its resistance to heat thus making it suitable for production of valves and lining of parts exposed to corrosive environment
At the same time its low coefficient of friction makes it finds a wide range of application in creating non-stick kitchen utensils.
As we all know that thermal stability implies to the effect of heating on a substance and chemical inertness means resistance towards any chemical action and we all know that Teflon shows both of these properties with high grade level making ‘A’ correct statement
Also we know that Teflon falls under the category of thermoplastic making statement ‘R’ also correct
But we cannot state that ‘R’ is the correct explanation of ‘A’ as high thermal stability and chemical inertness in Teflon is due to high bond energy of $C - C$ bond making the option ‘B’ as the most appropriate option.

Option B is the correct answer.

Note: Teflon is a highly crystalline linear polymer with a high melting point of $600K$ . It is insoluble in most of the solvent and is a very good electrical insulator.