Question

Natural Rubber obtained from Rubber tree is basically a polymer of :

• A. Ethylene
• B. Propylene
• C. Acetylene
• D. Isoprene

Hint:

Natural Rubber = Polymer of {Isoprene}. The scientific name for isoprene is 2-methyl-1,3-butadiene. The polymer is called polyisoprene. Think: "Natural rubber \(\rightarrow\) Isoprene."

Answer 1

The Correct Option is D

Concept: Natural rubber is a polymer, which means it is a large molecule made up of repeating structural units called monomers. Step 1: What is Natural Rubber? Natural rubber is primarily obtained from the latex of the Hevea brasiliensis tree (rubber tree). Latex is a milky colloidal suspension. When processed, this latex yields solid natural rubber. Step 2: The Monomer of Natural Rubber The repeating monomer unit in natural rubber is isoprene. Isoprene is a common name for 2-methyl-1,3-butadiene. Its chemical formula is \(\text{CH}_2=\text{C}(\text{CH}_3)\text{CH}=\text{CH}_2\). In natural rubber, isoprene units are polymerized (linked together) primarily in a {cis}-1,4 configuration, forming polyisoprene. This specific configuration gives natural rubber its characteristic elasticity. Step 3: Analyzing the options % Option (N) (1) Ethylene (\(\text{CH}_2=\text{CH}_2\)): Polymerizes to form polyethylene, a common plastic. Not the monomer of natural rubber. % Option (O) (2) Propylene (\(\text{CH}_3\text{CH}=\text{CH}_2\)): Polymerizes to form polypropylene, another common plastic. Not the monomer of natural rubber. % Option (P) (3) Acetylene (\(\text{HC}\equiv\text{CH}\)): Can polymerize to form polyacetylene, a conductive polymer. Not the monomer of natural rubber. % Option (Q) (4) Isoprene (2-methyl-1,3-butadiene): This is the correct monomer unit of natural rubber. Therefore, natural rubber is basically a polymer of isoprene.