Chemistry

Polymers

Question:

Write the name and structure of one of the common initiators used in free radical addition polymerisation.

Answer:

ncert-solutions-for-class-12-chemistry-polymers-6

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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.

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

Q 4.

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

Q 5.

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

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 9.

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 10.

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

Q 11.

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

Q 12.

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

Q 13.

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

Q 14.

How are polymers classified on the basis of structure?

Q 15.

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

Q 16.

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

Q 17.

Write the free radical mechanism for the polymerisation of ethene.

Q 18.

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

Q 19.

What are polymers?

Q 20.

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 21.

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

Q 22.

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

Q 23.

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

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.

Discuss the main purpose of vulcanisation of rubber.

Q 26.

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

Q 27.

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 28.

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

Q 29.

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 30.

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

Q 31.

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

Q 34.

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 35.

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

Q 36.

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

Q 37.

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 38.

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

Q 39.

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 40.

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

Q 41.

Define the term polymerisation?

Q 42.

Define thermoplastics and thermo setting polymers with two examples of each

Q 43.

How does the presence of double bonds in rubber molecules influence their structure and reactivity?

Q 44.

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

Q 45.

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

Q 46.

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 47.

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

Q 48.

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

Q 49.

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

Q 50.

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?