Chemistry

Polymers

Question:

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

Answer:

(c, d) Nylon and terylene are used as fibres due to strong intermolecular forces like H-bonding which lead to close packing in chain and thus impart crystalline nature.

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Polymers

Q 1.

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 2.

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

Q 3.

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

Q 4.

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 5.

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

Q 6.

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

Q 7.

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

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.

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 10.


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

Q 11.

Write the free radical mechanism for the polymerisation of ethene.

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.

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

Q 14.

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

Q 15.

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

Q 16.

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

Q 17.

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

Q 18.

What are polymers?

Q 19.

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 20.

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 21.

How are polymers classified on the basis of structure?

Q 22.

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

Q 23.

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

Q 24.

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

Q 25.

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

Q 26.

Discuss the main purpose of vulcanisation of rubber.

Q 27.

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

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.

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

Q 30.

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 31.

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

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.

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.

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

Q 35.

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 36.

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

Q 37.

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

Q 38.

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

Q 39.

Can enzyme be called a polymer?

Q 40.

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 41.

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

Q 42.

Explain the term copolymerisation and give two examples.

Q 43.

How is dacron obtained from ethylene glycol and terephthalic acid?

Q 44.

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

Q 45.

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

Q 46.

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 47.

Explain the terms polymer and monomer.

Q 48.

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

Q 49.

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

Q 50.

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