Chemistry

Polymers

Question:

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

Answer:

(a, d) Bakelite is a condensation polymer of phenol and formaldehyde. Melamine formaldehyde resin is a condensation polymer of melamine (2, 4, 6-triamino-1, 3, 5-triazine) and formaldehyde.

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Polymers

Q 1.

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

Q 2.

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

Q 3.

What are polymers?

Q 4.

Explain the terms polymer and monomer.

Q 5.

Can enzyme be called a polymer?

Q 6.

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

Q 7.

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

Q 8.

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

Q 9.

Why are rubbers called elastomers?

Q 10.

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

Q 11.

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

Q 12.

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

Q 13.

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

Q 14.

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

Q 15.

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

Q 16.

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 17.

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

Q 18.

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 19.

Define thermoplastics and thermo setting polymers with two examples of each

Q 20.

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

Q 21.

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

Q 22.

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

Q 23.

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 24.

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

Q 25.

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

Q 26.

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

Q 27.


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

Q 28.

Explain the term copolymerisation and give two examples.

Q 29.

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

Q 30.

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

Q 31.

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 32.

How is dacron obtained from ethylene glycol and terephthalic acid?

Q 33.

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

Q 34.

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

Q 35.

How do you explain the functionality of a monomer?

Q 36.

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

Q 37.

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 38.

How are polymers classified on the basis of structure?

Q 39.

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 40.

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

Q 41.

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

Q 42.

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

Q 43.

Match the polymers given in Column I with their main applications given in Column II.
ncert-exemplar-problems-class-12-chemistry-polymers-27

Q 44.

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

Q 45.

Write the free radical mechanism for the polymerisation of ethene.

Q 46.

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

Q 47.

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 48.

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

Q 49.

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 50.

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