Choose the correct option out of the following choices.

Assertion: For making rubber synthetically, isoprene molecules are polymerized. 

Reason:Neoprene (a polymer of chloroprene) is a synthetic rubber.

Assertion is incorrect but the reason is correct.

The correct answer is option 4. Assertion is incorrect but the reason is correct.

Assertion: For making rubber synthetically, isoprene molecules are polymerized.

This statement is incorrect. While isoprene (2-methyl-1,3-butadiene) is indeed polymerized to produce natural rubber, synthetic rubber can be made from various monomers. For example, neoprene is made from chloroprene, not isoprene.

Reason: Neoprene (a polymer of chloroprene) is a synthetic rubber.

This statement is correct. Neoprene is a type of synthetic rubber that is made by polymerizing chloroprene (2-chloro-1,3-butadiene).

Detailed Explanation:

1. Synthetic Rubber Production: Synthetic rubbers are produced by polymerizing various monomers. Some common types include:

Neoprene: Made by polymerizing chloroprene.

Buna-S (styrene-butadiene rubber): Made by polymerizing butadiene and styrene.

Buna-N (nitrile rubber): Made by polymerizing butadiene and acrylonitrile.

2. Natural Rubber: Natural rubber is primarily composed of polyisoprene, which is a polymer of isoprene. However, the assertion specifically refers to synthetic rubber production.

3. Neoprene: Neoprene is well-known for its chemical stability and is used in a variety of applications, including wetsuits, hoses, and gaskets. It is made by the polymerization of chloroprene, which differs from isoprene.

The assertion incorrectly identifies isoprene as the monomer used for making synthetic rubber in general, when in fact it is specifically used for natural rubber. The reason correctly identifies neoprene as a synthetic rubber made from chloroprene. Hence, the correct option is 4. Assertion is incorrect but the reason is correct.