NCERT Exemplar Class 12 Chemistry Chapter 15: Polymers. NCERT Exemplar Solutions for Class 12 Chemistry Chapter 15 Polymers prepare students for their Class 12 exams thoroughly.
Chemistry problems and solutions for the Class 12 pdf are provided here which are similar to the questions being asked in the previous year’s board.
NCERT Exemplar Class 12 Chemistry Chapter 15: Polymers
Class 12: Chemistry Chapter 15 solutions. Complete Class 12 Chemistry Chapter 15 Notes.
Multiple Choice Questions (Type-I)
- Which of the following polymers of glucose is stored by animals?
- (i) Cellulose
- (ii) Amylose
- (iii) Amylopectin
- (iv) Glycogen
- Which of the following is not a semisynthetic polymer?
- (i) cis-polyisoprene
- (ii) Cellulose nitrate
- (iii) Cellulose acetate
- (iv) Vulcanised rubber
- The commercial name of polyacrylonitrile is ______________.
- (i) Dacron
- (ii) Orlon (acrilan)
- (iii) PVC
- (iv) Bakelite
- Which of the following polymer is biodegradable?
- In which of the following polymers ethylene glycol is one of the monomer units?
- Which of the following statements is not true about low density polythene?
- (i) Tough
- (ii) Hard
- (iii) Poor conductor of electricity
- (iv) Highly branched structure
- Which of the following polymer can be formed by using the following monomer unit?
- (i) Nylon 6, 6
- (ii) Nylon 2–nylon 6
- (iii) Melamine polymer
- (iv) Nylon-6
Multiple Choice Questions (Type-II)
Note : In the following questions two or more options may be correct.
- Which of the following polymers, need atleast one diene monomer for their preparation?
- (i) Dacron
- (ii) Buna-S
- (iii) Neoprene
- (iv) Novolac
- Which of the folloiwng are characteristics of thermosetting polymers?
- (i) Heavily branched cross linked polymers.
- (ii) Linear slightly branched long chain molecules.
- (iii) Become infusible on moulding so cannot be reused.
- (iv) Soften on heating and harden on cooling, can be reused.
- Which of the following polymers are thermoplastic?
- (i) Teflon
- (ii) Natural rubber
- (iii) Neoprene
- (iv) Polystyrene
- Which of the following polymers are used as fibre?
- (i) Polytetrafluoroethane
- (ii) Polychloroprene
- (iii) Nylon
- (iv) Terylene
- Which of the following are addition polymers?
- (i) Nylon
- (ii) Melamine formaldehyde resin
- (iii) Orlon
- (iv) Polystyrene
- Which of the following polymers are condensation polymers?
- (i) Bakelite
- (ii) Teflon
- (iii) Butyl rubber
- (iv) Melamine formaldehyde resin
- Which of the following monomers form biodegradable polymers?
- (i) 3-hydroxybutanoic acid + 3-hydroxypentanoic acid
- (ii) Glycine + amino caproic acid
- (iii) Ethylene glycol + phthalic acid
- (iv) Caprolactum
- Which of the following are example of synthetic rubber?
- (i) Polychloroprene
- (ii) Polyacrylonitrile
- (iii) Buna-N
- (iv) cis-polyisoprene
- Which of the following polymers can have strong intermolecular forces?
- (i) Nylon
- (ii) Polystyrene
- (iii) Rubber
- (iv) Polyesters
- Which of the following polymers have vinylic monomer units?
- (i) Acrilan
- (ii) Polystyrene
- (iii) Nylon
- (iv) Teflon
- Vulcanisation makes rubber ______________.
- (i) more elastic
- (ii) soluble in inorganic solvent
- (iii) crystalline
- (iv) more stiff
Short Answer Type
- A natural linear polymer of 2-methyl-1, 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?
- Identify the type of polymer.
—A—A—A—A—A—A— - Identify the type of polymer.
—A—B—B—A—A—A—B—A— - Out of chain growth polymerisation and step growth polymerisation, in which type will you place the following.
- Identify the type of polymer given in the following figure.
- Identify the polymer given below :
- Why are rubbers called elastomers?
- Can enzyme be called a polymer?
- Can nucleic acids, proteins and starch be considered as step growth polymers?
- How is the following resin intermediate prepared and which polymer is formed by this monomer unit?
- To have practical applications why are cross links required in rubber?
- Why does cis-polyisoprene possess elastic property?
- 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?
- What is the role of benzoyl peroxide in addition polymerisation of alkenes? Explain its mode of action with the help of an example.
- Which factor imparts crystalline nature to a polymer like nylon?
- Name the polymers used in laminated sheets and give the name of monomeric units involved in its formation.
- Which type of biomolecules have some structural similarity with synthetic polyamides? What is this similarity?
- Why should the monomers used in addition polymerisation through free radical pathway be very pure?
Matching Type Questions
Note : Match the items of Column I with the items in Column II.
- Match the polymer of column I with correct monomer of column II.
- Match the polymers given in Column I with their chemical names given in Column II.
- Match the polymers given in Column I with their commercial names given in Column II.
- Match the polymers given in Column I with their main applications given in Column II.
- Match the polymers given in Column I with the preferred mode of polymerisation followed by their monomers.
- Match the polymers given in Column I with the type of linkage present in them given in Column II.
- Match materials given in Column I with the polymers given in Column II.
- Match the polymers given in Column I with their repeating units given in Column II.
Assertion and Reason Type Questions
Note : In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
(i) Assertion and reason both are correct statement but reason does not explain assertion.
(ii) Assertion and reason both are correct statements and reason explains the assertion.
(iii) Both assertion and reason are wrong statement.
|(iv) Assertion is correct statement and reason is wrong statement.
(v) Assertion is wrong statement and reason is correct statement.
- Assertion : Rayon is a semi synthetic polymer and is taken as a better choice than cotton fabric.
Reason : Mechanical and aesthetic properties of cellulose can be improved by acetylation. - Assertion : Most of the Synthetic polymers are not biodegradable.
Reason : Polymerisation process induces toxic character in organic molecules. - Assertion : Olefinic monomers undergo addition polymerisation.
Reason : Polymerisation of vinylchloride is initiated by peroxides/persulphates. - Assertion : Polyamides are best used as fibres because of high tensile strength.
Reason : 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. - Assertion : For making rubber synthetically, isoprene molecules are polymerised.
Reason : Neoprene (a polymer of chloroprene) is a synthetic rubber. - Assertion : Network polymers are thermosetting.
Reason : Network polymers have high molecular mass. - Assertion : Polytetrafluoroethene is used in making non-stick cookwares.
Reason : Fluorine has highest electronegativity.
Long Answer Type Question
- 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.
- Differentiate between rubbers and plastics on the basis of intermolecular forces.
- Phenol and formaldehyde undergo condensation to give a polymar (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?
- Low density polythene and high density polythene, both are polymers of ethene but there is marked difference in their properties. Explain.
- Which of the following polymers soften on heating and harden on cooling? What are the polymers with this property collectively called? What are the structural similarities between such polymers? Bakelite, urea-formaldehyde resin, polythene, polyvinyls, polystyrene.
Answers
