Question

Natural rubber is a polymer of which of the following?

• A. Ethylene
• B. Benzene
• C. Isoprene
• D. None of these

Hint:

Natural rubber = cis-1,4 polyisoprene; synthetic rubber (like neoprene) is made from other monomers.

Answer 1

The Correct Option is C

Step 1: Recall natural rubber structure.
Natural rubber is obtained from the latex of rubber trees. It is a polymer of isoprene units \(\big(\mathrm{CH_2=C(CH_3)-CH=CH_2}\big)\).
Step 2: Type of polymerization.
It is formed by 1,4-addition polymerization of isoprene, resulting in cis-1,4 polyisoprene.
Step 3: Analysis of options.
(A) Ethylene: Polymerizes to form polyethylene, not rubber.
(B) Benzene: Aromatic, not polymerized to rubber.
(C) Isoprene: Correct — forms natural rubber.
(D) None of these: Incorrect.
Step 4: Conclusion.
Thus, natural rubber is a polymer of isoprene.