Terylene forms via condensation polymerization of an acid and alcohol

Steps:

• Identify Terylene as a polyester, a type of condensation polymer.
• Recall polyesters form from dicarboxylic acids and diols (alcohols) like terephthalic acid and ethylene glycol.
• Confirm the reaction eliminates water molecules, characteristic of condensation polymerization.
• Rule out addition polymerization, which links monomers without byproducts and suits alkenes.

Why B is correct:

• Terylene is produced by reacting terephthalic acid (dicarboxylic acid) and ethane-1,2-diol (diol alcohol) in a condensation process, forming ester linkages with water elimination, as per the general polyester formation equation: HOOC-R-COOH + HO-R'-OH → [-OOC-R-COO-R'-O-] + H₂O.

Why the others are wrong:

• A: Addition polymerization applies to alkenes, not acid-alcohol reactions that form esters.
• C: Terylene uses acid and alcohol, not alkenes; addition suits polyalkenes like polythene.
• D: Condensation requires functional groups like acids/alcohols; alkenes undergo addition, not condensation.

Final answer: B