Chapter 15 Polymers

Question 1. Which of the following polymers of glucose is stored by animals?

(i) Cellulose

(ii) Amylose

(iii) Amylopectin

(iv) Glycogen

Question 2. Which of the following is not a semisynthetic polymer?

(i) cis-polyisoprene

(ii) Cellulose nitrate

(iii) Cellulose acetate

(iv) Vulcanised rubber

Question 3. The commercial name of polyacrylonitrile is ______________.

(i) Dacron

(ii) Orlon (acrilan)

(iii) PVC

(iv) Bakelite

Question 4. Which of the following polymer is biodegradable?

(i)

(ii)

(iii)

(iv)

Question 5. In which of the following polymers ethylene glycol is one of the monomer units?

(i)

(ii)

(iii)

(iv)

Question 6. Which of the following statements is not true about low density polythene?

(i) Tough

(ii) Hard

(iii) Poor conductor of electricity

(iv) Highly branched structure

Question 7. is a polymer having monomer units ____________.

(i)

(ii)

(iii)

(iv)

Question 8. Which of the following polymer can be formed by using the following monomer unit?

(i) Nylon 6, 6

(ii) Nylon 2–nylon 6

(iii) Melamine polymer

(iv) Nylon-6

Question 9. Which of the following polymers, need atleast one diene monomer for their preparation?

(i) Dacron

(ii) Buna-S

(iii) Neoprene

(iv) Novolac

Question 10. Which of the folloiwng are characteristics of thermosetting polymers?

(i) Heavily branched cross linked polymers.

(ii) Linear slightly branched long chain molecules.

(iii) Become infusible on moulding so cannot be reused.

(iv) Soften on heating and harden on cooling, can be reused.

Question 11. Which of the following polymers are thermoplastic?

(i) Teflon

(ii) Natural rubber

(iii) Neoprene

(iv) Polystyrene

Question 12. Which of the following polymers are used as fibre?

(i) Polytetrafluoroethane

(ii) Polychloroprene

(iii) Nylon

(iv) Terylene

Question 13. Which of the following are addition polymers?

(i) Nylon

(ii) Melamine formaldehyde resin

(iii) Orlon

(iv) Polystyrene

Question 14. Which of the following polymers are condensation polymers?

(i) Bakelite

(ii) Teflon

(iii) Butyl rubber

(iv) Melamine formaldehyde resin

Question 15. Which of the following monomers form biodegradable polymers?

(i) 3-hydroxybutanoic acid + 3-hydroxypentanoic acid

(ii) Glycine + amino caproic acid

(iii) Ethylene glycol + phthalic acid

(iv) Caprolactum

Question 16. Which of the following are example of synthetic rubber?

(i) Polychloroprene

(ii) Polyacrylonitrile

(iii) Buna-N

(iv) cis-polyisoprene

Question 17. Which of the following polymers can have strong intermolecular forces?

(i) Nylon

(ii) Polystyrene

(iii) Rubber

(iv) Polyesters

Question 18. Which of the following polymers have vinylic monomer units?

(i) Acrilan

(ii) Polystyrene

(iii) Nylon

(iv) Teflon

Question 19. Vulcanisation makes rubber ______________.

(i) more elastic

(ii) soluble in inorganic solvent

(iii) crystalline

(iv) more stiff

Question 20. A natural linear polymer of 2-methyl-1, 3-butadiene becomes hard on treatment with sulphur between 373 to 415 K and —S—S— bonds are formed between chains. Write the structure of the product of this treatment?

Question 21. Identify the type of polymer.

—A—A—A—A—A—A—

Question 22. Identify the type of polymer.

—A—B—B—A—A—A—B—A—

Question 23. Out of chain growth polymerisation and step growth polymerisation, in which type will you place the following.

or

Question 24. Identify the type of polymer given in the following figure.

Question 25. Identify the polymer given below :

Question 26. Why are rubbers called elastomers?

Question 27. Can enzyme be called a polymer?

Question 28. Can nucleic acids, proteins and starch be considered as step growth polymers?

Question 29. How is the following resin intermediate prepared and which polymer is formed by this monomer unit?

Question 30. To have practical applications why are cross links required in rubber?

Question 31. Why does cis-polyisoprene possess elastic property?

Question 32. What is the structural difference between HDP and LDP? How does the structure account for different behaviour and nature, hence the use of a polymer?

Question 33. What is the role of benzoyl peroxide in addition polymerisation of alkenes? Explain its mode of action with the help of an example.

Question 34. Which factor imparts crystalline nature to a polymer like nylon?

Question 35. Name the polymers used in laminated sheets and give the name of monomeric units involved in its formation.

Question 36. Which type of biomolecules have some structural similarity with synthetic polyamides? What is this similarity?

Question 37. Why should the monomers used in addition polymerisation through free radical pathway be very pure?

Question 38. Match the polymer of column I with correct monomer of column II.

Question 39. Match the polymers given in Column I with their chemical names given in Column II.

Question 40. Match the polymers given in Column I with their commercial names given in Column II.

Question 41. Match the polymers given in Column I with their main applications given in Column II.

Question 42. Match the polymers given in Column I with the preferred mode of polymerisation followed by their monomers.

Question 43. Match the polymers given in Column I with the type of linkage present in them given in Column II.

Question 44. Match materials given in Column I with the polymers given in Column II.

Question 45. Match the polymers given in Column I with their repeating units given in Column II.

Column I	Column II
(i) Acrilan	(a)
(ii) Polystyrene	(b)
(iii) Neoprene	(c)
(iv) Novolac	(d)
(v) Buna—N	(e)
	(f)

Question 46. Assertion : Rayon is a semi synthetic polymer and is taken as a better choice than cotton fabric.

Reason : Mechanical and aesthetic properties of cellulose can be improved by acetylation.

Question 47. Assertion : Most of the Synthetic polymers are not biodegradable.

Reason : Polymerisation process induces toxic character in organic molecules.

Question 48. Assertion : Olefinic monomers undergo addition polymerisation.

Reason : Polymerisation of vinylchloride is initiated by peroxides/ persulphates.

Question 49. Assertion : Polyamides are best used as fibres because of high tensile strength.

Reason : Strong intermolecular forces (like hydrogen bonding within polyamides) lead to close packing of chains and increase the crystalline character, hence, provide high tensile strength to polymers.

Question 50. Assertion : For making rubber synthetically, isoprene molecules are polymerised.

Reason : Neoprene (a polymer of chloroprene) is a synthetic rubber.

Question 51. Assertion : Network polymers are thermosetting.

Reason : Network polymers have high molecular mass.

Question 52. Assertion : Polytetrafluoroethene is used in making non-stick cookwares.

Reason : Fluorine has highest electronegativity.

Question 53. Synthetic polymers do not degrade in the environment for a long time. How can biodegradable synthetic polymers be made. Differentiate between biopolymers and biodegradable polymers and give examples of each type.

Question 54. Differentiate between rubbers and plastics on the basis of intermolecular forces.

Question 55. Phenol and formaldehyde undergo condensation to give a polymar (A) which on heating with formaldehyde gives a thermosetting polymer (B). Name the polymers. Write the reactions involved in the formation of (A). What is the structural difference between two polymers?

Question 56. Low density polythene and high density polythene, both are polymers of ethene but there is marked difference in their properties. Explain.

Question 57. Which of the following polymers soften on heating and harden on cooling? What are the polymers with this property collectively called? What are the structural similarities between such polymers? Bakelite, urea-formaldehyde resin, polythene, polyvinyls, polystyrene.