Important Questions for CBSE Class 12 Chemistry – Polymers

  

Important Questions for CBSE Class 12 Chemistry – Polymers

PREVIOUS YEARS QUESTIONS

2015 – Very Short Answer Type Questions [1 Mark]

Question 1:
Write the names and structures of the monomers of the following polymers:
(i) Nylon-6,6
(ii) Bakelite
(iii) Polystyrene
Answer:

Question 2:
Write the names and structures of the monomers of the following polymers:
(i) Glyptal
(ii) Teflon
(iii)Nylon-6
Answer:

Question 3:
Write the name and structures of the monomers of the following polymers:
(i) Buna-S
(ii) Glyptal
(iii) Polyvinyl chloride
Answer:

Question 4:
Write the names and structures of the monomers of the following polymers:
(i) Nylon-6
(ii) Novolac
(iii)Buna-N
Answer:

Question 5:
Write the names and structures of the monomers of the following polymers:
(i) Polystyrene
(ii) Nylon 6, 6
(iii) Terylene
Answer:

Question 6:
Describe the classification of polymers on the basis of structure.
Answer:

1.  Linear polymer: Those polymers in which monomer units are joined by straight chain, e.g. high density polymer.
2. Branched chain polymers: Those polymers in which monomer units are linked in branches also, e.g. low density polythene.
3.  Cross-linked polymers: It has 3-D network of cross linked polymers with cross links, e.g. Vulcanised rubber, Bakelite.

Question 7:
(a)Identify the monomer in the following structure :

(b) Arrange the following polymers in increasing order of intermolecular force of attraction: Nylon-6,6, Buna-S, Polythene.
(c) Based on molecular forces to which class of polymer do poly vinyls belong?
Answer:

Question 8:
Write the name and structures of the monomers of the following polymers:
(i) Nylon-6, 6
(ii) PHBV
(iii) Neoprene
Answer:

Question 9:
Write the names and structures of the monomers of the following polymers:

1.  Terylene
2.  Buna-S
3. Neoprene

Answer:

1. Refer Ans. to Q.5 (iii).
2. Refer Ans. to Q.3 (i).
3. Refer Ans. to Q.8 (iii).

Question 10:
Write the names and structures of the following polymers:

1.  Terylene
2.  Bakelite
3.  Buna-S

Answer:

1. Refer Ans. to Q.5 (ii).
2. Refer Ans. to Q.l (ii).
3. Refer Ans. to Q.3 (i).

Question 11:
Write the names and structures of the monomers of the following polymers:

1.  Buna-N
2.  Bakelite
3.  Teflon

Answer:

1. Refer Ans. to Q.4 (Hi).
2. Refer Ans. to Q. 1 (ii).
3.  Refer Ans. to Q. 2 (ii).

2014 – Very Short Answer Type Questions [1 Mark]

Question 12:
Which of the following is a natural polymer?
Answer:
Buna-S, Proteins, PVC

Question 13:
Based on molecular forces what type of polymer is neoprene?
Answer:
Elastomer.

Question 14::
Which of the following is a fibre?
Nylon, Neoprene, PVC
Answer:
Nylon is a fibre.

Question 15:
Name the compound which on polymerisation gives neoprene.
Answer:
Chloroprene (2-chlorobuta-l, 3-diene)

Question 16:
How does homopolymer differ from copolymer?
Answer:
Homopolymer is formed by repeating the same monomer unit, whereas copolymer is formed by repeating two different monomers.

Short Answer Type Questions [I] [2 Marks]

Question 17:
Write the name of monomers used for getting the following polymers

1. Bakelite
2.  Neoprene

Answe:

1. Phenol and Methanal (formaldehyde)
2. Chloroprene (2-chloro-Buta 1, 3-diene)

Question 18:
Write the name of monomers used for getting the following polymers:

1. Teflon
2.  Buna-N

Answer:

1.  Tetrafluoroethene (CF2=CF2)
2.  Buta 1, 3-diene and prop-2-enenitrile

Question 19:
Write the name of monomers used for getting the following polymers:

1.  Terylene
2.  Nylon- 6,6

Answer:

1.  Terephthalic acid (Benzene 1, 4-dicarboxylic acid) and glycol (Ethane 1,2-diol)
2. Adipic acid (Hexane 1, 6 dioic acid) and Hexamethylenediamine (Hexane 1, 6-diamine).

Question 20:
Write structures and IUPAC names of monomers of the following polymers:
(а) Buna-S
(b) Nylon-6, 6.
Answer:

Question 21:
Write the names of the nonomers used for getting the following polymers:

1.  Teflon
2. Bakelite
3. Neoprene

Answer:

1.  Tetrafluoro ethene
2.  Phenol and Formaldehyde
3.  2-Chloro buta 1,3-diene.

Question 22:
Give names of monomers of the following polymers:

1.  Neoprene
2.  Polystyrene
3.  Polypropene

Answer:

1. 2-Chloro buta-1,3-diene
2.  Styrene (phenyl ethene)
3.  Propene.

Value Based Questions

Question 23:
After the ban on plastic bags, students of one school decided to make the people aware of the harmful effects of plastic bags on environment and Yamuna River. To make the awareness more impactful, they organized rally by joining hands with other schools and distributed paper bags to vegetable vendors, shopkeepers and departmental stores. All students pledged not to use polythene bags in future to save Yamuna River.
After reading the above passage, answer the following questions:

1. What values are shown by the students?
2. What are biodegradable polymers? Give one example.
   
3.  Is polythene a condensation or an addition polymer?

Answer:

1.  Students are concerned about the environment and want to save Yamuna river from pollution. ‘
   
2.  Those polymers which are decomposed by the micro-organisms are called biodegradable polymers, e.g. PHBV.
   
3. Polythene is an addition polymer.

2013 – Very Short Answer Type Questions [1 Mark]

Question 24:

Answer:
It is a homopolymer.

Question 25:
Give one example of a condensation polymer.
Answer:
Nylon 6,6

Question 26:

Answer:
It is a homopolymer.

Question 27:
Write the names of monomers of the polymer:

Answer:

Question 28:

Answer:

Question 29:

Answer:

Short Asnwer Type Questions [I][2 Marks]

Question 30:
Define thermoplastic and thermosetting polymers. Give one example of each.
Answer:
Thermoplastics: They are plastics which become soft on heating and can be remoulded. They have less forces, e.g. polythene.
Thermosetting polymers: They do not become soft on heating and cannot be remoulded. They have strong force of attraction, e.g. bakelite.

Question 31:
What is a biodegradable polymer? Give an example of a biodegradable aliphatic polyester.
Answer:
Biodegradable polymers are those which are decomposed by micro-organisms. In biological systems, biopolymers degrade mainly by enzymatic hydrolysis and to some extent by oxidation, e.g. PHBV (poly p-hydroxybutyrate – co -P- hydroxy valerate), polyglycolic acid and polylactic acid.

Question 32:
Arrange the following polymers in increasing order of their intermolecular forces:

1. Nylon-6,6, Buna-S, Polythene
2. PVC, Nylon-6, Neoprene

Answer:

1. Buna-S < Polythene < Nylon-6,6
2. Neoprene < PVC < Nylon-6

Short Answer Type Questions [II] [3 Marks]

Question 33:
Write the names and structures of the monomers of the following polymers:

1. Buna-S
2. Neoprene
3. Nylon-6, 6

Answer:

1. Refer Ans. to Q.3 (i).
2.  Refer Ans. to Q.8 (iii).
3. Refer Ans. to Q.l (i).

Question 34:
Write the names and structures of the monomers of the following polymers:

(i) Polystyrene
(ii) Dacron
(iii) Teflon
Answer:

Question 35:
Write the names and structure of the monomers of the following polymers:

1.  Bakelite
2.  Nylon-6
3. Polythene

Answer:

1. 1. Refer Ans. to Q.l (ii).
   2. Refer Ans. to Q.2 (iii).
   3. CH2 = CH2       (Ethene)

 

2012 – Very Short Answer Type Questions [1 Mark]

Question 36:
Define the term, ‘homopolymerisation’ giving an example.
Answer:
The process in which only one type of monomer undergoes polymerisation
is called homopolymerisation, e.g. formation of polythene from ethene is homopolymerisation.

Question 37:
Draw the structure of the monomer for the polymer: Polypropene
Answer:
CH2=CH—CH3
Propene

Question 38:
Draw the structure of the monomer for each of the following polymers:

1. Nylon-6
2.  Polypropene

Answer:

1.  Refer Ans. to Q.2 (in).
2.  CH3—CH=CH2 (Propene)

Question 39:
Differentiate between molecular structure and behaviours of thermoplastic and thermosetting polymers. Give one example of each type.

Answer:

Short Answer Type Questions [II] [3 Marks]

Question 40:
Explain the following terms giving a suitable example for each:

1.  Elastomers
2.  Condensation polymers
3.  Addition polymers.

Answer:

1. Elastomers: The polymers in which polymer chains are held together by the weakest intermolecular forces. These weak forces permit the polymer to be stretched. A few ‘cross-links’ are introduced in between the chains which help the polymer to retract to its original position after the force is released, as in vulcanised rubber.
2.  Condensation polymers: It involves a series of condensation reactions generally involving two monomers. Each monomer normally contains two functional groups. The condensation reactions result in the loss of small molecules usually water and ammonia, e.g. nylon, terylfene, bakelite are condensation polymers. This process is known as ‘condensation polymerisation’.
3. Addition polymers: The polymers which are formed by repeated addition of monomers to the polymer chain. The monomers are unsaturated compounds and commonly derivatives of ethene. The addition polymers have same empirical formula as their monomers, e.g.
   

Question 41:
Differentiate between thermoplastic and thermosetting polymers. Give one example of each
Answer:
Refer Ans. to Q.39.

Question 42:
Write the structure of the monomer of each of the following polymers.

1. Nylon-6
2. Teflon
3. Neoprene

Answer:

1. Refer Ans. to Q.2 (in).
2. Refer Ans. to Q.2 (ii).
3. Refer Ans. to Q.8 (in).

2011 – Very Short Answer Type Questions [1 Mark]

Question 43:
What is the repeating structural unit in polythene polymer?
Answer:

Question 44:
What are biodegradable polymers?
Answer:
Those polymers which are decomposed by micro-organisms and do not create
pollution are biodegradable, e.g. PHBV.

Question 45:
In nylon 6, 6 what does the designation ‘6, 6’ mean? [Delhi]
Answer:
It means both monomers contain six carbon atoms each.

Short Answer Type Questions [I] [2 Marks]

Question 46:
Name the sub-groups into which polymers are classified on the basis of magnitude of intermolecular forces.
Answer:

1.  Elastomers
2.  Fibres
3. Thermoplastics
4. Thermosetting polymers.

Question 47:
Draw the molecular structures of the monomers of

1.  PVC
2. Teflon

Answer:

1. CH2=CH—Cl is the monomer of PVC.
2. CF2=CF2 is the monomer of Teflon.

Question 48:
What are biodegradable polymers? Give two examples.
Answer:
Biodegradable polymers are those polymers which are decomposed by
micro-organisms. In biological systems, biopolymers degrade mainly by enzymatic hydrolysis and to some extent by oxidation, e.g. PHBV (poly- P-hydroxybutyrate-co-p-hydroxy valerate), poly glycolic acid and poly lactic acid.

Question 49:
Mention two important uses of each of the following:

1.  Bakelite
2.  Nylon 6

Answer:

1. Bakelite: It is used for making electric switch.
   It is used for making switch boards.
2. Nylon 6: It is used for making socks and stockings.
   It is used for making climbing ropes and parachute fabrics.

Short Answer Type Questions [II] [3 Marks]

Question 50:
Write the names and structures of the monomers of the following polymers:

1. Buna-S
2.  Dacron
3. Neoprene

Answer:

1.  Refer Ans. to Q.3 (i).
2.  Refer Ans. to Q.34 (ii).
3.  Refer Ans. to Q.8 (iii).

Question 51:
Mention two important uses of each of the following polymers:

1. Bakelite
2. Nylon 6,6
3. PVC

Answer:

1.  Refer Ans. to Q.49 (i)
2. Nylon 6,6: It is used in stockings.
   It is used in making ropes and fabrics.
3.  PVC: It is used in making hosepipes.
   It is used for insulation of electric wires.

Question 52::
What are addition polymers? How are the two types of addition polymers different from each other? Give one example of each type.
Answer:

Question 53::
Draw the structure of the monomers of the following polymers:

1. polythene
2.  PVC
3.  Teflon

Answer:

1. CH2=CH2
2.  CH2 = CHCI
3.  CF2=CF2

Question 54:
(a) What does the designation “6, 6’ in nylon 6, 6 polymer mean?
(b) Which polymer is obtained when free radical polymerisation of chloroprene occurs? Write the structure of the polymer thus obtained?
Answer:

2010 – Very Short Answer Type Questions [1 Mark]

Question 55:
What does the designation ‘6, 6’ mean in the name nylon-6, 6?
Answer:
Refer Ans. to Q.45.

Question 56:

Draw the molecular structure of the monomers of

1. PVC
2. Teflon

Answer:

1.  CH2=CHC1
2. CF2 = CF2

Question 57:
What is meant by ‘copolymerisation’?
Answer:
When two or more types of monomers undergo addition or condensation reaction to form polymer, it is called copolymerisation.

Short Answer Type Questions [I] [2 Marks]

Question 58:

Draw the structures of the monomers of the following polymers:

1. Bakelite
2. Nylon-6

Answer:

1. Refer Ans. to Q.l (ii).
2. Refer Ans. to Q.2 (iii).

Short Answer Type Questions [II] [3 Marks]

Question 59:

Give one example each of

1. addition polymers,
2.  condensation polymers,
3. copolymers.

Answer :

1. Polythene or PVC is an example of addition polymer.
2. Nylon-6,6 or Nylon-6 is an example of condensation polymer.
3.  Buna-S or Buna-N is an example of copolymer.

Question 60:
Identify the four groups into which the polymers are classified on the basis of the magnitude of intermolecular forces present in them. To which group or groups do polythene and bakelite belong?
Answer:
Elastomers: The polymers in which polymer chains are held together by the weakest intermolecular forces.
Fibres: The polymers which are used for making fibres possess high tensile strength and high modulus. There are strong intermolecular forces of attraction like hydrogen bonding, e.g. in nylon-6,6.
Thermoplastics: The intermolecular forces of attraction in thermoplastic polymers are moderate. Polythene belongs to thermoplastics.
Thermosetting polymers: These polymers are made from low molecular mass semi-liquid polymers which when heated in a mould become infusible and form an insoluble hard mass. These have stronger force of attraction due to cross linkage.
Bakelite is a thermosetting polymer.

Question 61:
Write the name and structure of the monomer of each of the following polymers:

1.  Neoprene
2. Buna-S
3. Teflon

Answer:

1. Refer Ans. to Q.8 (iii).
2. Refer Ans. to Q.3 (i).
3.  Refer Ans. to Q.2 (ii).

Question 62:
Differentiate between thermoplastic and thermosetting polymers. Give one example of each.
Answer:
Refer Ans. to Q.39.

Question 63:
Write the structure of the monomer of each of the following polymers:

1. Polyvinyl chloride
2. Teflon
3. Bakelite

Answer:

1.  CH2=CH—Cl
2. Refer Ans. to Q.2 (ii).
3.  Refer Ans. to Q.l (it).

Question 64:
Write the (i) structure and (ii) one use of each of the following polymers:
(a) PVC
(b) Urea-formaldehyde resin
(c) Bakelite
Answer:

2009 – Very Short Answer Type Questions [1 Mark]

Question 65:
What is the repeating structural unit in polythene polymer?
Answer:

Question 66:
Give an example of elastomers.
Answer:
Natural rubber or Buna-S or Buna-N or Neoprene is an elastomer.

Question 67:
What does the part ‘6, 6’ mean in the name nylon-6, 6?
Answer :
It means each monomer of nylon has six carbon atoms.
For example, adipic acid HOOC—(CH2)4—COOH and hexamethylenediamine
H2N—(CH2)6—NH2. ‘
Answer :

Question 68:
What is the primary structure feature necessary for a molecule to make it useful in a condensation polymerisation reactions?
Answer:
Monomers should have more than one functional group (bifunctional).

Question 69:
Draw the structure of the monomers of the following polymers:
(i) Teflon (ii) Polythene
Answer:
(i) CF2=CF2 (ii) CH2=CH2

Question 70:
Differentiate between molecular Structures and behaviours of thermoplastic and thermosetting polymers. Give one example of each type.
Answer:
Refer Ans. to Q.39.

Question 71:
What is the repeating unit in the condensation polymer obtained by combining H02CCH2CH2C02H (succinic acid) and H2NCH2CH2NH2 (ethylenediamine)?
Answer:

Short Answer Type Questions [II] [3 Marks]

Question 72:
Differentiate between the modes of formation of an addition polymer and a condensation polymer. Give one example of each of these formations.
Answer:

Question 73:
Draw the structures of the monomers  of the following materials:
(i) PVC
(ii) Teflon
(iii) Neoprene
Answer: