Question

Natural rubber or raw rubber consists of basic material latex which is a dispersion of isoprene. During the treatment this isoprene forms a high molecular weight polymer of isoprene. Natural rubber can be obtained from five hundred different species of plants.
Consider the following properties of rubber,
(i) Tensile strength of vulcanised rubber is almost ten times more than raw rubber.
(ii) Elasticity of raw rubber is very high. Choose the correct option.

• A. (i) is true (ii) is false
• B. (i) is false (ii) is true
• C. Both (i) and (ii) are true
• D. Both (i) and (ii) are false

Answer 1

Answer: (C)

The elasticity of raw rubber is very high-
The cis-polyisoprene molecule consists of various chains held together by weak van der Waals interactions and has a coiled structure. Thus, it can be stretched like a spring and exhibits elastic properties.
The tensile strength of vulcanized rubber is almost ten times more than raw rubber- The cross-linking of sulphur increases the tensile strength of vulcanized rubber.