Chemistry

Polymers

Question:

How can you differentiate between addition and condensation polymerisatiop?

Answer:

In addition polymerization, the molecules of the same or different monomers simply add on to one another leading to the formation of a macromolecules without elimination of small molecules like H2O, NH3 etc. Addition polymerization generally occurs among molecules containing double and triple bonds. For example, formation of polythene from ethene and neoprene from chloroprene, etc. In condensation polymerisation, two or more bifunctional trifimctional molecules undergo a series of independent condensation reactions usually with the elimination of simple molecules like water, alcohol, ammonia, carbon dioxide and hydrogen chloride to form a macromolecule. For example, nylon-6,6 is a condensation polymer of hexamethylenediamine and adipic acid formed by elimination of water molecules.

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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.

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 4.

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

Q 5.

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

Q 6.

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

Q 7.

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 8.

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

Q 9.

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

Q 10.


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

Q 11.

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

Q 12.

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

Q 13.

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

Q 14.

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

Q 15.

Write the free radical mechanism for the polymerisation of ethene.

Q 16.

What are polymers?

Q 17.

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 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.

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

Q 21.

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 22.

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

Q 23.

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 24.

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

Q 25.

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

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.

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

Q 28.

Discuss the main purpose of vulcanisation of rubber.

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.

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

Q 31.

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

Q 32.

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

Q 33.

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 34.

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

Q 35.

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

Q 36.

Phenol and formaldehyde undergo condensation to give a polymer (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?

Q 37.

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

Q 38.

Can enzyme be called a polymer?

Q 39.

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

Q 40.

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

Q 41.

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

Q 42.

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

Q 43.

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 44.

How do you explain the functionality of a monomer?

Q 45.

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

Q 46.

How is dacron obtained from ethylene glycol and terephthalic acid?

Q 47.

Which of the following polymer can be formed by using the following monomer unit?
ncert-exemplar-problems-class-12-chemistry-polymers-10

Q 48.

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

Q 49.

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

Q 50.

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