Q1. Natural rubber is a polymer of:
Explanation
Natural rubber is mainly cis-1,4-polyisoprene, so its monomer is isoprene. Buna-N is a synthetic rubber made from butadiene and acrylonitrile, not the source monomer of natural rubber. Caprolactam is used to make nylon-6, a polyamide fibre. Neoprene is polychloroprene, another synthetic rubber. These three are related to polymer chemistry, but they do not identify the monomer unit of natural rubber. Isoprene therefore fits the question exactly.
