Ques. 1AIPMT 2001
Which of the following is not correctly matched?
- Neoprene : [figure]
- Nylon-6,6 : [figure]
- Terylene : [figure]
- PMMA : [figure]
Answer
(3) Terylene : [figure]
Solution
As per NCERT, terylene (dacron) is a polyester formed by condensation of ethylene glycol and terephthalic acid, so an ester oxygen lies on both sides of the -CH2-CH2- unit:
[figure]
⇒ In the given structure the oxygen between CH2 and C=O is missing, so terylene is not correctly matched.
∵ Neoprene (from chloroprene), nylon-6,6 (from hexamethylenediamine and adipic acid) and PMMA (from methyl methacrylate) are shown with their correct repeating units.
Answer: (3)
Out of syllabus