Chemistry

Polymers

Question:

Identify the polymer given below:
ncert-exemplar-problems-class-12-chemistry-polymers-20

Answer:

The polymer is cis-polyisoprene (natural rubber), since the polymer is formed by 1, 4-addition of 2-methyl buta-1, 3-diene (isoprene).

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Polymers

Q 1.

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

Q 2.

Is  (-NH — CHR—CO-)n a homopolymer or copolymer?

Q 3.

What are polymers?

Q 4.

Explain the terms polymer and monomer.

Q 5.

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

Q 6.

Can enzyme be called a polymer?

Q 7.

Identify the type of polymer.
-A-A-A-A-A-A-

Q 8.

What is a biodegradable polymer ? Give an example of a biodegradable aliphatic polyester.

Q 9.

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.

Q 10.

Write the monomers used for gettingThe following polymers:
(i) Polyvinylchloride
(ii) Teflon (iii) Bakelite

Q 11.

Write the free radical mechanism for the polymerisation of ethene.

Q 12.

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

Q 13.

Vulcanisation makes rubber .
(a) more-elastic (b) soluble in inorganic solvent
(c) crystalline (d) more stiff

Q 14.

Explain the difference between Buna- N and Buna-S.

Q 15.

Which of the following polymers are condensation polymers?
(a) Bakelite (b) Teflon
(c) Butyl rubber (d) Melamine formaldehyde resin

Q 16.

Identify the type of polymer.
-A-B-B-A-A-A-B-A-

Q 17.

Identify the type of polymer given in the following figure.
ncert-exemplar-problems-class-12-chemistry-polymers-19

Q 18.

Why are rubbers called elastomers?

Q 19.

Assertion (A): Network polymers are thermosetting.
Reason (R): Network polymers have high molecular mass.

Q 20.

Match the polymers of Column I with correct monomers of Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-25

Q 21.

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

Q 22.

Which of the following are characteristics of thermosetting polymers?
(a) Heavily branched cross linked polymers.
(b) Linear slightly branched long chain molecules.
(c) Become infusible on moulding so cannot be reused.
(d) Soften on heating and harden on cooling, can be reused.

Q 23.

Which of the following polymers are thermoplastic?
(a) Teflon (b) Natural rubber (c) Neoprene (d) Polystyrene

Q 24.

Vulcanisation makes rubber .
(a) more-elastic (b) soluble in inorganic solvent
(c) crystalline (d) more stiff

Q 25.

Identify the polymer given below:
ncert-exemplar-problems-class-12-chemistry-polymers-20

Q 26.

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?

Q 27.

Assertion (A): Polytetrafluoroethene is used in making non-stick cookware. Reason (R): Fluorine has highest electronegativity.

Q 28.

What are natural and synthetic polymers? Give two examples of each type.

Q 29.

How is dacron obtained from ethylene glycol and terephthalic acid?

Q 30.


ncert-exemplar-problems-class-12-chemistry-polymers-7
ncert-exemplar-problems-class-12-chemistry-polymers-8

Q 31.

Which of the following polymers, need at least one diene monomer for their preparation?
(a) Dacron (b) Buna-S (c) Neoprene (d) Novolac

Q 32.

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

Q 33.

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

Q 34.

Assertion (A): Network polymers are thermosetting.
Reason (R): Network polymers have high molecular mass.

Q 35.

How do you explain the functionality of a monomer?

Q 36.

Identify the monomer in the following polymeric structures:
ncert-solutions-for-class-12-chemistry-polymers-10

Q 37.

Which of the following polymer is biodegradable?
ncert-exemplar-problems-class-12-chemistry-polymers-2
ncert-exemplar-problems-class-12-chemistry-polymers-3

Q 38.

Which of the following are addition polymers?
(a) Nylon (b) Melamine formaldehyde resin
(c) Orion (d) Polystyrene

Q 39.

Which of the following polymers can have strong intermolecular forces?
(a) Nylon (b) Polystyrene (c) Rubber (d) Polyester

Q 40.

Which of the following polymers have vinylic monomer units?
(a) Acrilan (b) Polystyrene (c) Nylon (d) Teflon

Q 41.

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?

Q 42.

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

Q 43.

Match the polymers given in Column I with the type of linkage present in them given in Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-30

Q 44.

In the following questions, a statement of Assertion (A) followed by a statement of
Reason (R) is given. Choose the correct answer out of the following choices:
(a) Assertion and Reason both are correct statements but Reason is not the correct explanation of Assertion.
(b) Assertion and Reason both are correct statements and Reason is the correct explanation of Assertion.
(c) Both Assertion and Reason are false.
(d) Assertion is correct but Reason is false.
(e) Assertion is false but Reason is correct.

Assertion (A): Rayon is a semi-synthetic polymer and is taken as a better choice than cotton fabric.
Reason (R): Mechanical and aesthetic properties of cellulose can be improved by acetylation.

Q 45.

Assertion (A): Olefinic monomers undergo addition polymerization.
Reason (R): Polymerisation of vinyl chloride is initiated by peroxides/ persulphates.

Q 46.

Assertion (A): Polyamides are best used as fibres because of high tensile strength.
Reason (R): 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.

Q 47.

Classify the following as addition and condensation polymers:
Terylene, Bakelite, Polyvinyl chloride,Polythene

Q 48.

Arrange the following polymers in increasing order of their intermolecuiar forces.
(i) Nylon 6,6, Buna-S, Polythene
(ii) Nylon 6, Neoprene, Polyvinyl chloride

Q 49.

Distinguish between the terms homopolymer and copolymer and give an example of each.

Q 50.

Define the term polymerisation?