Chemistry

Polymers

Question:

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.

Answer:

(b) Polyamides like nylons are best used fibres. They have high tensile strength due to presence of strong inter molecular hydrogen bond.

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Polymers

Q 1.

Which of the following polymers are used as fibre?
(a) Polytetrafluoroethane (b) Poly chloroprene
(c) Nylon (d) Terylene

Q 2.

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

Q 3.

Match materials given in Column I with the polymers given in Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-31

Q 4.

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

Q 5.

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

Q 6.

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

Q 7.

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

Q 8.

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 10.

Out of chain growth polymerisation and step growth polymerisation, in which type will you place the following.
ncert-exemplar-problems-class-12-chemistry-polymers-18

Q 11.

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

Q 12.

Match the polymers given in Column I with their chemical names given in Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-26

Q 13.

In which of the following polymers ethylene glycol is one of the monomer units?
ncert-exemplar-problems-class-12-chemistry-polymers-5

Q 14.

Write the free radical mechanism for the polymerisation of ethene.

Q 15.

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

Q 16.

What are polymers?

Q 17.

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

Q 18.

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

Q 19.

How are polymers classified on the basis of structure?

Q 20.

Write the names and structures of the monomers of the following polymers:
(i) Buna-S (ii) Buna-N (iii) Dacron (iv) Neoprene

Q 21.

Discuss the main purpose of vulcanisation of rubber.

Q 22.

In which classes, the polymers are classified on the basis of molecular forces?

Q 23.

Which of the following are examples of synthetic rubber?
(a) Polychloroprene (b) Polyacrylonitrile
(c) Buna-N (d) cis-polyisoprene

Q 24.

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

Q 25.

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 26.

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

Q 27.

Match the polymers given in Column I with their repeating units given in Column 11.
ncert-exemplar-problems-class-12-chemistry-polymers-32

Q 28.

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 29.

How is the following resin intermediate prepared and which polymer is formed by this monomer unit?
ncert-exemplar-problems-class-12-chemistry-polymers-21

Q 30.

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 31.

Assertion (A): For making rubber synthetically, isoprene molecules are polymerised.
i Reason (R): Neoprene (a polymer of chloroprene) is a synthetic rubber.

Q 32.

Assertion (A): For making rubber synthetically, isoprene molecules are polymerised.
i Reason (R): Neoprene (a polymer of chloroprene) is a synthetic rubber.

Q 33.

Which of the following monomers form biodegradable polymers?
(a) 3-hydroxybutanoic acid +3-hydroxypentanoic acid
(b) Glycine + aminocaproic acid  
(c) Ethylene glycol + phthalic acid
(d) Caprolactam

Q 34.

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

Q 35.

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

Q 36.

Write the names of the monomers of the following polymers:
ncert-solutions-for-class-12-chemistry-polymers-1
ncert-solutions-for-class-12-chemistry-polymers-2

Q 37.

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

Q 38.

Match the polymers given in Column I with their main applications given in Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-28

Q 39.

Define thermoplastics and thermo setting polymers with two examples of each

Q 40.

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

Q 41.

Assertion (A): Most of the synthetic polymers are not biodegradable.
Reason (R): Polymerisation process induces toxic character in organic molecules.

Q 42.

What are the monomeric repeating units of Nylon-6 and Nylon 6,6?

Q 43.

A natural linear polymer of 2-methyl-l,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?

Q 44.

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

Q 45.

Match the polymers given in Column I with their main applications given in Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-29

Q 46.

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

Q 47.

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

Q 48.

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 49.

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

Q 50.

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