If $\bar{M}_w$ is the weight average molecular weight and $\bar{M}_n$ is the number average molecular weight of a polymer, the poly dispersity index $(PDI)$ of the polymer is given by

Which of the following statements are correct?
$(1)$ Biodegradable polymers can be converted into essential life substances after degradation.
$(2)$ Non-biodegradable polymers are active towards environmental processes.
$(3)$ Non-biodegradable polymers can be converted into essential life substances.
$(4)$ $PHBV$ is degraded by bacteria under environmental conditions.

Which of the following statements is incorrect?

Orlon fibres are made up of:

Consider the following sequence of reactions.
$2 CH_3Cl + Si$ $\xrightarrow[573 \ K]{Cu} X$ $\xrightarrow{H_2O} Y$ $\xrightarrow{\text{Polymerization}} Z$
The repeating structural unit in $Z$ is

Intermolecular forces in nylon-$6,6$ are