Given below are two statements, one is Assertion (A) and other is Reason (R).
Assertion (A) : Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason (R) : The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure.
In the light of the above statements, choose the correct one from the options given below :
Assertion (A) : Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason (R) : The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure.
In the light of the above statements, choose the correct one from the options given below :
- (A)Both (A) and (R) are true and (R) is the correct explanation of (A)
- (B)Both (A) and (R) are true but (R) is not the correct explanation of (A).
- (C)(A) is true but (R) is false.✓ Correct
- (D)(A) is false but (R) is true.
Answer: (C)
Solution
Assertion (A) is correct: Natural rubber is indeed a linear polymer of isoprene (2-methyl-1,3-butadiene) with the cis-1,4-configuration, and it exhibits elastic properties. However, Reason (R) is false: The cis-polyisoprene chains are held together by weak van der Waals interactions, not strong polar interactions. The coiled structure is correct, but the nature of the intermolecular forces is incorrectly stated. Therefore, (A) is true but (R) is false.
JEE Main · 2022 · 28 Jun 2022 · Shift 2 · Single correct option