MCQ Questions for Class 12 Engineering Chemistry Polymers Quiz 2

The number of

π -

$\pi-$ bonds present in the monomer of polyacrylonitrile is:

0%
$2$
0%
$1$
0%
$3$
0%
$4$

Explanation

Polyacrylonitrile is obtained from a monomer, acrylonitrile having the structure as

C H_{2} = C H - C N

$CH_2=CH-CN$ .

Cyano group contains two

π

$\pi$ -bonds and a

σ

$\sigma$ -bond.

A double bond is present between two carbon atoms.

Thus, three

π -

$\pi -$ bonds are present in the monomer.

Which of the following is the IUPAC name of the aromatic monomer is present in melmac?

0%
$2,\: 4,\: 6$ -Triamino - $1,\: 3,\: 5$ - triazine
0%
Methanal
0%
$1,\: 3,\: 5$ - Triamine - $2,\: 4,\: 6$ - triazine
0%
Melamine

The formation of polyethylene from calcium carbide takes places as follows :

C a C_{2} + 2 H_{2} O \to C a (O H)_{2} + C_{2} H_{2}

$CaC_2 + 2H_2O \rightarrow Ca(OH)_2+C_2H_2$

C_{2} H_{2} + H_{2} \to C_{2} H_{4}

$C_2H_2+H_2\rightarrow C_2H_4$

n C_{2} H_{4} \to (C H_{2} - C H_{2})_{n}

$nC_2H_4\rightarrow (CH_2-CH_2)_n$
The amount of polyethylene obtained from

64

$64$ kg of

C a C_{2}

$CaC_2$ is :

0%
$14$ kg
0%
$7$ kg
0%
$21$ kg
0%
$28$ kg

Explanation

Mass of

C a C_{2}

$Ca{ C }_{ 2 }$ =

64

$64$ Kg

Moles of

C a C_{2}

$Ca{ C }_{ 2 }$ = 64/64 =

1000

$1000$ mol

C a C_{2} + 2 H_{2} O \to C a (O H)_{2} + C_{2} H_{2}

$CaC_2 + 2H_2O \rightarrow Ca(OH)_2+C_2H_2$

For 1000 mole of

C a C_{2}

$Ca{ C }_{ 2 }$ , We get 1000 mole of

C_{2} H_{2}

${ C }_{ 2 }{ H }_{ 2 }$

C_{2} H_{2} + H_{2} \to C_{2} H_{4}

$C_2H_2+H_2\rightarrow C_2H_4$

For 100 mole of

C_{2} H_{2}

${ C }_{ 2 }{ H }_{ 2 }$ , we get 1000 mole of

C_{2} H_{4}

${ C }_{ 2 }{ H }_{ 4 }$

n C_{2} H_{4} \to (C H_{2} - C H_{2})_{n}

$nC_2H_4\rightarrow (CH_2-CH_2)_n$

For n mole

C_{2} H_{2}

${ C }_{ 2 }{ H }_{ 2 }$ , we get 1 mole of polyethylene.

For 1000 mole of

C_{2} H_{2}

${ C }_{ 2 }{ H }_{ 2 }$ , we get

(\frac{1000}{n}) \times 1

$(\dfrac { 1000 }{ n } )\times 1$

Number of moles of polyethylene formed are 1000/n.

Molecular weight of polyethylene is

n \times [(2 \times 12) + (2 \times 4)] = 28 n

$n\times [(2\times 12)+(2\times 4)]=28n$

Mass of polyethylene produced

=

$=$ Number of moles

\times

$\times$ Molecular weight

= (\frac{1000}{n}) \times 28 n

$=(\dfrac { 1000 }{ n } )\times 28n$

= 28000

$=28000$ gram

= 28

$=28$ kg

Option D is correct.

Which of the following is not correctly matched?

Statement 1: Polybutadiene is an example of step growth polymer.
Statement 2: Copolymerisation of butadiene and acrylonitrile gives Buna-N.

0%
Statement 1 and statement 2 is true and statement 2 is the correct explanation of statement 1
0%
Statement 1 and statement 2 is true but statement 2 is not the correct explanation of statement 1
0%
Statement 1 is true and statement 2 is false
0%
Statement 1 is false and statement 2 is true

Which of the following sets contains only co-polymers ?

0%
PVC, Neoprene
0%
Polythene, Polyester
0%
Nylon-6, Teflon
0%
Melmac, Bakelite

Which of the following is the biodegradable polymer of polyamide class ?

0%
Nylon - $6,\: 6$
0%
Nylon - $2$ - nylon - $6$
0%
Dextran
0%
PHBV

Explanation

Biodegradable is defined as being able to be broken down by other living organisms. Nylon-

2

$2$ -nylon-

6

$6$ , Dextran and PHBV are biodegradable, whereas, Nylon -

6, 6

$6,\:6$ is non-biodegradable.

However, Dextran and PHBV, both are polyesters and Nylon-

2

$2$ -nylon-

6

$6$ is a polyamide. Dextran is formed by the polymerization of many glucose molecules.

The PDI (polydisersity index) is the ratio of weight to number-average molecular masses,

M ¯ w / M ¯ n

$M \bar{w} / M \bar{n}$ . In natural polymers, which are generally monodispersed, PDI is ............. and in synthetic polymers which are always polydispersed, PDI is ............. because

M ¯ w

$M \bar {w}$ is always ............. than

M ¯ n

$M \bar {n}$ . Fill in the blanks.

0%
greater than $1$ , $1$ , higher
0%
$1$ , greater than $1$ , higher
0%
less than $1$ , $1$ , lower
0%
$1$ , less than $1$ , lower

Explanation

The PDI (polydisersity index) is the ratio of weight to number-average molecular masses,

M ¯ w / M ¯ n

$M \bar{w} / M \bar{n}$ . In natural polymers, which are generally monodispersed, PDI is 1 and in synthetic polymers which are always polydispersed, PDI is greater than 1 because

M ¯ w

$M \bar {w}$ is always higher than

M ¯ n

$M \bar {n}$ .

Statement 1: Teflon has high thermal stability and chemical inertness.

Statement 2: It has strong C-F bonds.

Choose the correct option:

0%
Statement 1 is true: Statement 2 is true; statement 2 is the correct explanation of statement 1
0%
Statement 1 is true: statement 2 is true; statement 2 is not the correct explanation of statement 1
0%
Statement 1 is true; statement 2 is false
0%
Statement 1 is false; statement 2 is true

Which of the following is a step-growth polymer ?

0%
Polyacrylonitrile
0%
Polyisoprene
0%
Nylon
0%
Polythene

Explanation

Step-growth polymerization refers to a type of polymerization mechanism in which bi-functional or multifunctional monomers react to form first dimers, then trimers, longer oligomers and eventually long-chain polymers.

For example, Nylon polymerizes by the step-growth polymerization process in which difunctional monomers containing equal parts of amine and carboxylic acid react so that amides are formed at both ends of each monomer
Polyacrylonitrile, Polyisoprene and Polythene polymerize by chain-growth polymerization of acrylonitrile, isoprene (

2

$2$ -methyl-

1, 3

$1,\:3$ -butadiene) and ethene, respectively.

Chain-growth polymerization (or addition polymerization) involves the linking together of molecules incorporating double or triple carbon-carbon bonds.

Which of the following are condensation copolymers ?

0%
Nylon - $6$
0%
Nylon - $6, \:6$
0%
Dacron
0%
Glyptal

The monomeric repeating units of nylon -

6

$6$ is:

0%
caprolactam
0%
phenol and formaldehyde
0%
tetrafluoroethylene
0%
butadiene

Explanation

Monomer (repeating unit) of Nylon -

6

$6$ is caprolactam.
Monomer (repeating unit) of Nylon -

6, 6

$6,\:6$ is derived from two monomers, hexamethylenediamine, and adipic acid.

Which one of these is a monomer of Bakelite?

0%
Vinyl acetate
0%
Tetrafluoroethylene
0%
Formaldehyde
0%
Propylene

The polymer that can be classified as polyester polymer is:

0%
Bakelite
0%
Melamine
0%
Nylon-6, 6
0%
Terylene

Which of the following processes can be used to prepare polystyrene ?

0%
Anionic
0%
Cationic
0%
Free radicals
0%
Ziegler-Natta

What is the monomer unit for teflon?

Explanation

Teflon is a plastic-like substance which is produced by polymerizing tetrafluoroethylene (

C F_{2} = C F_{2}

$CF_{2} = CF_{2}$ ).

And is also known as Polytetrafluoroethylene.

Which of the following are made of polyamides ?

0%
Wool
0%
Natural silk
0%
Rayon
0%
Nylon

Explanation

Polyamide, any polymer or substance composed of long, multiple-unit molecules in which the repeating units in the molecular chain are linked together by amide groups. Amide groups have the general chemical formula

C O - N H

$CO-NH$ .

(A) Wool - It is a polyamide.

(B) Natural silk - It is a polyamide.

(D) Nylon - It is a polyamide.

Which of the following are biopolymers ?

0%
Nucleic acids
0%
Leather
0%
Baklite
0%
Orlon

Which material is used for vulcanisation of rubber?

0%
Iron
0%
Sulphur
0%
Chlorine
0%
Calcium Carbonate

Explanation

The material used for the vulcanisation of rubber is sulphur.

The reasons why the rubber is vulcanised are as follows:

i) It is soft and sticky and becomes more so at high temperature and brittle at low temperature. That is why, it is used at low-temperature range (

280 - 330

$280-330$ ) K, where its elasticity is maintained.
ii) It is attacked by oxygen and other oxidising agents.
iii) It has a high water absorption capacity, low tensile strength and low resistance to abrasion.
iv) It is reactive to organic solvents.
Therefore, natural rubber is vulcanised by heating it with about (

3 - 5 %

$3-5\%$ ) sulphur at (

373 - 415

$373-415$ ) K.

The chemical name of melamine is_________.

0%
$2,4$ -Diamino-1 $,3,5$ -triazine
0%
$2$ -Amino- $1,3,5$ -triazine
0%
$2,4,6$ -Triamino- $1,3,5$ -triazine
0%
$1,3,5$ -Triamino- $2,4,6$ -triazine

Which of the following is not a condensation polymer ?

0%
Nylon - $6,\: 6$
0%
PTFE
0%
Dacron
0%
Glyptal

Explanation

Condensation polymers are any kind of polymers formed through a condensation reaction where molecules join together losing small molecules as by-products such as water or methanol, e.g., Nylon-

6, 6

$6,\:6$ , Dacron (or Terylene) and Glyptal etc.
This is opposed to addition polymers, which involve the reaction of unsaturated monomers, e.g. PTFE.

Which one of the following polymer is prepared by condensation polymerization?

0%
Polystyrene
0%
Nylon - $6,\:6$
0%
Teflon
0%
Rubber

Explanation

Condensation polymers are formed through a condensation reaction, where molecules join together, losing small molecules as byproducts. For e.g., Nylon -

6, 6

$6,\:6$ is formed by condensation polymerization of adipic acid and hexamethylenediamine.
Whereas Polystyrene, Teflon and Rubber all are formed by chain-growth polymerization of monomers styrene, tetrafluoroethylene and isoprene respectively.
Here, an unsaturated monomer molecule adds to the active site of a growing polymeric chain one at a time.

Option B is correct.

The product that you would expect to obtain from catalytic hydrogenation of natural rubber is_________.

0%
syndiotactic
0%
atactic
0%
isotactic
0%
either atatic or isotatic

Explanation

Atactic

$\text { Atactic }$

These are the polymers formed by free radical mechanisms with a random orientation of groups.

Bakelite is ___.

0%
rubber
0%
rayon
0%
brittle plastic
0%
plasticisers

Silk worm : Cocoon :: Wool: ?

0%
Hair of rabbit
0%
Cotton plant
0%
Fleece of sheep
0%
Jute of hemp

The plastic product which can be remoulded is

0%
bakelite
0%
melamine
0%
polyethene
0%
polycot

Teflon is :

0%
a natural fibre
0%
a synthetic fibre
0%
a polymer
0%
a cellulose

Explanation

Hint: A polymer is formed from the condensation or addition of monomers.

Correct Answer: Option C

Explanation:

Teflon is the result of the polymerization reaction of Tetrafluoroethylene.

The reaction is as follows:

$\mathop {{\text{n}}{{\text{F}}_2}{\text{C}}}\limits_{\text{ }} = {\text{C}}{{\text{F}}_2}\xrightarrow{\Delta }\left( {{{\text{F}}_2}{\text{C}} - {\text{C}}{{\text{F}}_2}} \right){ _{\text{n}}}$

Which of the following is/are not a condensation copolymer?

0%
Nylon- $6$
0%
Nylon- $6,6$
0%
Dacron
0%
PVC

$\begin{bmatrix}-CH_2-\underset{\underset{\textstyle\;OH}{\displaystyle\mid}}{\;\;\;CH}-CH_2-\underset{\underset{\textstyle\;OH}{\displaystyle\mid}}{\;\;\;CH}-CH_2-\underset{\underset{\textstyle\;OH}{\displaystyle\mid}}{\;\;\;CH}-\end{bmatrix}_n$

Polyvinyl alcohol (as shown above) is a unique polymer having high affinity for water. Which of the following procedures would be most suitable for its preparation?

0%
radical chain polymerisation of $CH_2=CH-CH_2-OH$
0%
radical chain polymerisation of $CH_2=CH-OH$
0%
radical chain polymerisation of $CH_2=CH-CO_2CH_3$ , following by base catalysed hydrolysis
0%
radical chain polymerisation of $CH_2=CH-OCOCH_3$ , followed by acid catalysed hydrolysis
0%
radical chain polymerisation of $CH_2=CH-OCOCH_3$ , followed by base catalysed hydrolysis

Explanation

Polyvinyl alcohol is prepared by radical chain polymerisation of

$CH_2=CH-OCOCH_3$ , followed by base catalysed hydrolysis in which acetate group is replaced by hydroxide group.

The repeating unit present in nylon

$-6$ is:

0%
$-[NH(CH_{2})_{6}NHCO(CH_{2})_{4}CO]-$
0%
$-[CO(CH_{2})_{5}NH]-$
0%
$-[CO(CH_{2})_{6}NH]-$
0%
$-[CO(CH_{2})_{4}NH]-$
0%
$-[NH(CH_{2})_{4}NHCO(CH_{2})_{6}CO]-$

Explanation

The monomer in

$nylon - 6$ is caprolactum.

Amnio caproic acid is produced from the hydrolysis of caprolactum.

$\underset {\text {Amnio caproic acid}}{H_2N-(CH_2)_5-COOH} \xrightarrow{\Delta, \, polymerisation} \underset{Nylon-6}{-\!\![NH - (CH_2)_5-\overset{O}{\overset{||}{C}}-\!\!\!]_n}$

$Nylon - 6$ is used in making fibres plastics, tyre cords and ropes.

Hence, option B is correct.

The monomers used in preparation of dextron are:

0%
lactic acid and glycolic acid
0%
3-hydroxy butanoic acid and 3-hydroxy pentanoic acid
0%
styrene and 1, 3-butadiene
0%
hexamethylenediamine and adipic acid

Tubeless tyres are co-polymers of isoprene and :

0%
neoprene
0%
silicons
0%
isobutylene
0%
PAN

Explanation

Tubeless tyres are copolymers of isoprene and isobutylene.

Isobutylene is

$\displaystyle CH_2=C(CH_3)_2$ . It is also called 2-methylprop-1-ene.

Isoprene is

$\displaystyle CH_2=C(CH_3)-CH=CH_2$ . It is also called 2-methyl-1,3-butadiene.

Hence, option C is correct.

Which one of the following statement is not true?

0%
Natural rubber has trans configuration at every double bond
0%
BUNA-S is copolymer of butadiene and styrene
0%
Natural rubber is 1,4 polymer of isoprene
0%
In vulcanization, the formation of sulphur bridges between different chains makes rubber harder and stronger

Under high pressure and in presence of nickel cyanide catalyst, acetylene on polymerisation gives:

0%
Benzene
0%
Mesitylene
0%
Cyclo-octatetraene
0%
Vinyl acetylene

Which of the following is/are true for teflon?

0%
It is yellow, dense, amorphous, extremely chemically reactive compound.
0%
It is good electrical conductor.
0%
It has self lubricating property.
0%
It is used in manufacturing artificial hip joints used for the patients with arthritis.

When 280 gm of ethylene polymerises to polyethene according to the equation.

$nCH_2=CH_2 \longrightarrow -(CH_2-CH_2)_n-$

The weight and mole of polyethylene formed will be:

0%
280, 10n
0%
$\displaystyle \frac{280}{n}$ , n
0%
$\displaystyle \frac{280}{n}$ , 280
0%
280, $\displaystyle \frac{10}{n}$

Explanation

During polymerization of ethylene to polyethylene, no atoms are lost or added to ethylene. Thus, total mass of ethylene is equal to total mass of polyethylene. 280 gm of ethylene polymerises to give 280 gm of polyethylene.

The molar mass of ethylene is 28 g/mol. 280 gm of ethylene

$= \dfrac {280 g}{28 g/mol} = 10$ mol.

$nCH_2=CH_2 \xrightarrow { \text { polymerization }} (-CH_2-CH_2-)_n$

n moles of ethylene will give 1 mole and

$n\times 28$ gm of polyethylene

10 moles of ethylene will give

$\dfrac{10}{n}$ moles and

$n\times 28 = 10 \times 28 = 280$ gm of polyethylene.

Option D is correct.

Teflon is an example of polymer which is a/an:

0%
polyamide
0%
addition polymer
0%
polyester
0%
formaldehyde resin

Explanation

Teflon is prepared by the combination of a large number of tetrafluoroethylene molecules, without the elimination of any small molecule. Therefore, it is an example of addition homopolymer.

$nCF_{2} = CF_{2} \rightarrow -[CF_{2} - CF_{2}]-_{n}$ .

Which among the following is not a natural polymer?

0%
Wool
0%
Silk
0%
Rubber
0%
PVC

Explanation

There are two types of polymers: synthetic and natural.

Synthetic polymers are derived from petroleum oil and made by scientists and engineers. Examples of synthetic polymers include nylon, polyethene, polyester, Teflon, and epoxy.

$\text {Polyvinyl chloride}$ , commonly abbreviated PVC, is the third-most widely produced synthetic plastic polymer.

Natural polymers occur in nature and can be extracted. Examples of naturally occurring polymers are silk, wool, DNA, cellulose and proteins and rubber.

Option D is correct

During long distance travel you would like to take drinking water in a bottle made up of :

0%
glass
0%
plastic
0%
leather
0%
steel

PP (Polypropylene) is used for making _____________.

0%
disposable cups
0%
liquid detergents
0%
grocery bags
0%
electric switches

Which of the following are polyesters?

Cotton, Terylene, Nylon, PET, Rayon, Acrylic.

0%
Cotton, Nylon, Rayon
0%
Acrylic, PET, Cotton
0%
Terylene, PET, Acrylic
0%
PET, Nylon, Rayon

The polymer, which is the constituent of cotton is:

0%
cellulose
0%
ester
0%
rayon
0%
nylon

Explanation

Cotton is 99% cellulose. Cellulose is a macromolecule. A polymer made up of a long chain of glucose molecules linked by

$C-1$ to

$C-4$ oxygen bridges with an elimination of water. Wood pulp, rayon, and cellophane are also constructed of cellulose polymers.

Rubber is heated with sulphur and the process is known as:

0%
Galvanization
0%
Vulcanization
0%
Bessemerization
0%
Sulphonation

The monomer of Buna-S are:

0%
styrene and butadiene
0%
isoprene and butadiene
0%
vinyl chloride and Sulphur
0%
butadiene.

When formaldehyde is heated with phenol in the presence of an alkali, the product formed is:

0%
rubber
0%
bakelite
0%
chloroprene
0%
neoprene

Explanation

Bakelite forms in a condensation reaction of phenol and formaldehyde, with wood flour or asbestos fiber as a filler, under high pressure and heat in a time frame of a few minutes of curing. The result is a hard plastic material.

Molecular Formula :

$({ C }_{ 6 }{ H }_{ 6 }O.C{ H }_{ 2 }O)_{ n }$

Making Bakelite was a multi-stage process. It began with the heating of phenol and formaldehyde in the presence of a catalyst such as hydrochloric acid, zinc chloride, or the base ammonia

The polymer formed by condensation of adipic acid and hexamethylene diamine is:

0%
Isoprene
0%
Rayon
0%
Terylene
0%
Nylon- $6, 6$

Bakelite is obtained from phenol by reaction with :

$1$

0%
Acetaldehyde
0%
Acetal
0%
Formaldehyde
0%
Chlorobenzene

What is Modacrylic?

0%
Modified acrylic
0%
Natural fibre acrylic
0%
Acrylic and polyester
0%
None of above

The monomer of Natural Rubber is:

0%
$\begin{matrix}CH_2 &=&C&-&CH&=&CH_2 \\&&|&\\&&\, \, \,\, \, \, \,\,CH_3\end{matrix}$
0%
$\begin{matrix}&&\, \, \,\,Cl\\&&|&\\CH_2 &=&C&-&CH&=&CH_2 \end{matrix}$
0%
$CH_2=CH - CH = CH_2$
0%
None of these

Explanation

$\bf{Hint:}$ Chemical name for natural rubber is polyisoprene.

$\bf{Explanation \ for \ Correct \ Option:}$

Natural rubber is a polymer of isoprene. Natural rubber is an example of an additional polymer as it is formed by the repeating unit of a monomer known as isoprene.

Each monomer of isoprene has

$2$ double bonds and has molecular formula as

$C_5H_8$ so it is diene.

Isoprene has structure

$\bf{Explanation \ for \ Incorrect \ Option:}$

Compound in Option

$B$ is chloroprene and it is a monomer of polymer neorepene.

Compound in option

$C$ is

$1,3-butadiene$ and it is monomer of polymer polybutadiene.

$\bf{Final \ answer:}$ Option

$A$

Which of the following is an addition polymer ?

0%
Neoprene
0%
Teflon
0%
Polyvinylchloride
0%
All of the above

Explanation

$\bf{Hint:}$ An addition polymer is formed by chain-growth polymerization by repeating the unit of monomers.

$\bf{Explanation:}$

Addition polymer is a polymer formed by the direct reaction of two or more monomers, and with no resulting water or other by-products.

Neoprene is formed by the free radical polymerisation of chloroprene

Teflon is formed from the monomer tetrafluoroethylene by its repeated addition.

Polyvinyl chloride is produced in an additional polymerisation reaction using the chloroethene (vinyl chloride) monomer.

All of the compounds that are Neoprene, Teflon, and polyvinyl chloride are addition polymers.

$\bf{Final \ answer:}$ Option

$D$

CBSE Questions for Class 12 Engineering Chemistry Polymers Quiz 2 - MCQExams.com

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

CBSE Questions for Class 12 Engineering Chemistry Polymers Quiz 2 - MCQExams.com

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Practice Class 12 Engineering Chemistry Quiz Questions and Answers

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