Write the names and the structures of monomers of following polymer :
(i) Natural rubber
(ii) Terylene.

Answer

To answer the question regarding the monomers of the polymers natural rubber and terylene, we will break down the solution into clear steps.

### Step-by-Step Solution:

**(i) Natural Rubber:**
1. **Identify the Monomer:** The monomer of natural rubber is isoprene.
2. **Structure of Isoprene:** The chemical structure of isoprene is represented as:
\[ \text{CH}_2=\text{C}(\text{CH}_3)-\text{CH}=\text{CH}_2 \]
This can also be written in a more structured format:
\[ \text{C}_5\text{H}_8 \quad \text{(2-methylbuta-1,3-diene)} \]
3. **Polymer Structure:** When isoprene polymerizes, it forms polyisoprene, which is the main component of natural rubber. The repeating unit in polyisoprene is in a cis configuration.

**(ii) Terylene:**
1. **Identify the Monomers:** Terylene is formed from two monomers: terephthalic acid and ethylene glycol.
2. **Structure of Terephthalic Acid:** The structure of terephthalic acid is:
\[ \text{C}_6\text{H}_4(\text{COOH})_2 \]
This can be depicted as:
\[ \text{HOOC}-\text{C}_6\text{H}_4-\text{COOH} \]
3. **Structure of Ethylene Glycol:** The structure of ethylene glycol is:
\[ \text{HO}-\text{CH}_2-\text{CH}_2-\text{OH} \]
4. **Polymer Structure:** Terylene (also known as Dacron) is formed through the condensation reaction between terephthalic acid and ethylene glycol, resulting in the following structure:
\[ \text{[-CO-}\text{C}_6\text{H}_4\text{-CO-O-CH}_2\text{-CH}_2\text{-]}_n \]

### Summary of Monomers:
- **Natural Rubber:** Monomer - Isoprene (2-methylbuta-1,3-diene)
- **Terylene:** Monomers - Terephthalic acid and Ethylene glycol