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

Options

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

To solve the question regarding the properties of natural rubber, we need to analyze the statements given about vulcanized rubber and raw rubber.

### Step-by-Step Solution:

1. **Understanding Natural Rubber**:
- Natural rubber is derived from latex, which is a dispersion of isoprene.
- Isoprene undergoes polymerization to form high molecular weight polymers, specifically polyisoprene.

2. **Analyzing the First Property**:
- The first statement claims that the tensile strength of vulcanized rubber is almost ten times more than that of raw rubber.
- **Vulcanization** is a process that involves adding sulfur to rubber, which creates cross-links between the polymer chains.
- This cross-linking significantly enhances the tensile strength of the rubber.
- Therefore, this statement is **true**.

3. **Analyzing the Second Property**:
- The second statement states that the elasticity of raw rubber is very high.
- Raw rubber, primarily composed of cis-polyisoprene, has a coiled structure with chains held together by weak Van der Waals forces.
- This structure allows raw rubber to stretch and return to its original shape, exhibiting high elasticity.
- Thus, this statement is also **true**.

4. **Choosing the Correct Option**:
- Both statements about the properties of rubber are true.
- Therefore, the correct option is that both the first and second statements are true.

### Final Answer:
The correct option is: **Both first and second are true.**

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