Question

Terylene is a condensation polymer of ethylene glycol and

• A. benzoic acid
• B. phthalic acid
• C. salicylic acid
• D. terephthalic acid

Answer 1

The Correct Option is D

Terylene, also known as polyester, is a condensation polymer that is formed through the chemical reaction between ethylene glycol and terephthalic acid. Let's break down why terephthalic acid is the correct answer among the options provided:

1. Understanding Condensation Polymers: Condensation polymers are formed through a reaction where monomers join together, with the loss of small molecules such as water or methanol. In the case of Terylene, the reaction involves the loss of water molecules.
2. Monomers for Terylene: Terylene is specifically made from two monomers: ethylene glycol (a diol) and terephthalic acid (a dicarboxylic acid).
3. The Reaction Process: The condensation polymerization process for forming Terylene involves the esterification of the hydroxyl (-OH) groups of ethylene glycol with the carboxyl (-COOH) groups of terephthalic acid. This results in the formation of ester linkages with the release of water molecules. \text{HO-CH}_2\text{-CH}_2\text{-OH} + \text{HOOC-C}_6\text{H}_4\text{-COOH} \rightarrow \text{-OOC-C}_6\text{H}_4\text{-COO-CH}_2\text{-CH}_2\text{-} + \text{H}_2\text{O}
4. Justification for Terephthalic Acid: Among the given options, only terephthalic acid can effectively form the polymer used to create Terylene. Both benzoic acid, phthalic acid, and salicylic acid do not have the structural configuration needed to form long-chain linear polyesters with ethylene glycol.
5. Conclusion: Based on the chemistry of polyester formation and fundamental polymerization reactions, the correct choice is terephthalic acid. This leads to the creation of Terylene through the condensation process with ethylene glycol.

Therefore, the correct answer is terephthalic acid.