Engineering Chemistry MCQ (Thermoplastic Polymers )

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Engineering Chemistry MCQ (Thermoplastic Polymers )

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Thermoplastic Polymers – 1

1. The thermoplastic is ____________
a) Cross-linked
b) Insoluble
c) Amorphous
d) Held by a covalent bond
Answer: c
Explanation: Thermoplastics are linear or branched, soluble in suitable solvents,
amorphous or semi-crystalline and held together by weak vander waal’s force or hydrogen bonds.

2. Which of the following is not an example of thermoplastic?
a) Nylon
b) Polyester
c) PVC
d) Vulcanised rubber
Answer: d
Explanation: The examples of thermoplastic are nylon, polyester, PVC,PE, PP, PVA etc.

3. Polythene is prepared by the process of __________________ polymerisation of ethylene.
a) Addition
b) Condensation
c) Living
d) Free-radical
Answer: a
Explanation: Polythene is prepared by the process of addition polymerisation of
ethylene. Polythene is of low strength, hardness and rigidity, but has a high ductility
and impact strength as well as low friction.

4. LDPE is prepared by polymerising ethylene at a pressure of ____________
a) 100-200 atmospheres
b) 1000-5000 atmospheres
c) 10-100 atmospheres
d) 2-10 atmospheres
Answer: b
Explanation: None.

5. The crystallinity of LDPE is ____________
a) 10%
b) 30%
c) 55%
d) 80-90%
Answer: c
Explanation: The crystallinity of LDPE is low (55%). LDPE is defined by a density
range of 0.910–0.940 g/cm3.

6. Select the incorrect statement from the following option.
a) LDPE is chemically inert and has excellent chemical resistance
b) LDPE is tough and flexible
c) LDPE is used for making films in general packaging, carrier bags etc
d) LDPE has high rigidity and is suitable for load bearing applications
Answer: d
Explanation: LDPE has low rigidity and is not suitable for load bearing applications. All other options are correct.

7. LDPE is suitable for the manufacture of pipes for distribution of gas.
a) True
b) False
Answer: b
Explanation: LDPE is not suitable for the manufacture of pipes for distribution of gas
because it is permeable to gas molecules. LDPE is widely used for manufacturing
various containers, dispensing bottles, wash bottles etc.

8. The ethylene is polymerised under in the presence of ____________
a) Zeigler Natta catalyst
b) Supported metal oxide catalyst
c) Lewis acids catalyst
d) Friedel crafts catalyst
Answer: a
Explanation: The ethylene is polymerised under 6-7 atmospheric pressure at 60-700C in the presence of Zeigler Natta catalyst.

9. The softening temperature of HDPE is ____________
a) 200C
b) 850C
c) 1350C
d) 1500C
Answer: c
Explanation: The softening temperature of HDPE is 1350C. HDPE is known for its
large strength-to-density ratio.The density of HDPE can range from 0.93 to 0.97
g/cm3 or 970 kg/m3.

10. Select the incorrect statement from the following option.
a) HDPE has excellent electrical insulation properties
b) HDPE is free from odour and toxicity
c) HDPE can be used for domestic water and gas piping
d) HDPE possess lower tensile strength compared to LDPE
Answer: d
Explanation: HDPE possess greater tensile strength compared to LDPE. All the other
options are correct.


Thermoplastic Polymers – 2

1. Which of the following act as a catalyst in the preparation of PVC?
a) Lewis acid
b) Benzoyl peroxide
c) Potassium amide
d) Grignard reagent
Answer: b
Explanation: Benzoyl peroxide act as a catalyst in the preparation of PVC. The
product of the polymerization process is unmodified PVC.

2. Select the incorrect statement from the following option.
a) PVC is colourless, odourless and non-inflammable
b) PVC has poor oil resistance and resistance to weathering
c) PVC is used for making bottles for consumable liquids
d) PVC has superior chemical resistance but is soluble in ethyl chloride
Answer: b
Explanation: PVC has excellent oil resistance and resistance to weathering. It is
colorless, odourless and non-inflammable and is used for making bottles for
consumable liquids. PVC has poor oil resistance and resistance to weathering.

3. The C-Cl dipole makes PVC a polymeric polar molecule.
a) True
b) False
Answer: a
Explanation: The C-Cl dipole makes PVC a polymeric polar molecule.PVC has
excellent oil resistance and resistance to weathering. It is colorless, odourless and non-inflammable.

4. Plasticized PVC is not used for making ____________
a) Baby-pants
b) Bathroom curtaining
c) Pipes for drainage
d) Garden hose
Answer: c
Explanation: Plasticised PVC is not used for making pipes for drainage. It is used for making baby-pants, bathroom curtaining and garden hose.

5. Which of the following is also known as lucite?
a) Teflon
b) Polyvinyl acetate
c) Polystyrene
d) Perspex
Answer: d
Explanation: Perspex is also known as lucite. It is a solid transparent plastic made of polymethyl methacrylate.

6. Which of the following is used for making chewing gums?
a) Perspex
b) Polyvinyl acetate
c) Teflon
d) Polystyrene
Answer: b
Explanation: Polyvinyl acetate is used for making chewing gums. It is also used in handicrafts, envelope and wallpaper adhesives.

7. Which of the following statement is incorrect about the Teflon?
a) It has high density of the order 2.1 to 2.3 gm/cm3
b) It has excellent electrical insulation properties
c) It has high coefficient of friction
d) It is dense and chemically inert
Answer: c
Explanation: Teflon has very low coefficient of friction. All the other options are correct.

8. Which of the following is an application of Teflon?
a) Coatings of frying pans
b) Combs and brush handles
c) Audio cassettes
d) Optical fibres
Answer: a
Explanation: Coatings of frying pans, non-lubricating bearings, wire and cable
insulation etc are some of the applications of Teflon. it is also used as liners in hose assembly.

9. Polystyrene is prepared by ___________ polymerisation of styrene.
a) Condensation
b) Free radical
c) Anionic
d) Cationic
Answer: b
Explanation: Polystyrene is prepared by free radical polymerisation of styrene in the presence of benzoyl peroxide as catalyst.

10. The softening temperature of polystyrene is ____________
a) 10-20 0C
b) 30-50 0C
c) 80-100 0C
d) 120-150 0C
Answer: c
Explanation: The softening temperature of polystyrene is 80-100 0C. Polystyrene is a
vinyl polymer. Structurally, it is a long hydrocarbon chain, with a phenyl group
attached to every other carbon atom.

11. Due to the chain stiffening effect of a benzene ring, polystyrene is hard but brittle.
a) True
b) False
Answer: a
Explanation: Due to chain stiffening effect of a benzene ring, polystyrene is hard but
brittle. Polystyrene is also used for producing disposable plastic cutlery and dinnerware

12. Which of the following is an application of polystyrene?
a) Insulators for motors
b) Dome-shaped covers for solar collectors
c) Laminates for printed circuitry
d) Containers for talcum powder
Answer: d
Explanation: Containers for talcum powder, combs and brush handles, audio
cassettes etc are some of the applications of polystyrene. But it is not used as
insulators for motors or covers for solar collectors.