Engineering Chemistry Multiple Choice Questions on “Organic Conducting Polymers”.
1. Which of the following is used for making rechargeable batteries?
a) Polypyrrole
b) Polyester
c) Polyaniline
d) Polyacrylonitrile
Answer: c
Clarification: Polyaniline is used for making rechargeable batteries in the shape of flat buttons or as laminated rolled films.
2. The advantage of using conducting polymers in place metals is their ____________
a) Cost
b) Light-weight
c) Thermal conductivity
d) Solubility
Answer: b
Clarification: The advantage of using conducting polymers in place metals is their light-weight and they do not corrode.
3. During the polymerisation of polyaniline, the sequence of the colour change is ____________
a) Green >> copper tint >> blue green >> light blue
b) Light blue >> blue green >> copper tint >> green
c) Copper tint >> blue green >> green >> light blue
d) Blue green >> green >> light blue >> copper tint
Answer: b
Clarification: During the polymerisation of polyaniline, the sequence of the colour change is Light blue >> blue green >> copper tint >> green.
4. The precipitate is dried under vacuum at 60-80 0C for ____________
a) 1 hour
b) 2 hours
c) 5 hours
d) 8 hours
Answer: d
Clarification: The precipitate is dried under vacuum at 60-80 0C for 8hours for complete dehydration process.
5. The color of emeraldine salt which is obtained is ____________
a) Copper tint
b) Blue green
c) Green
d) Light blue
Answer: c
Clarification: The color of emeraldine salt which is obtained is green. The emeraldine salt form of polyaniline is highly electrically conducting.
6. The final washings of the salt is done with ____________
a) Distilled water
b) Diethyl ether
c) Methanol
d) Acetone
Answer: b
Clarification: The final washings of the salt is done with diethyl ether for cleaning it completely.
7. Conducting polymers having conjugation is a type of intrinsically conducting polymers.
a) True
b) False
Answer: a
Clarification: Conducting polymers having conjugation is a type of intrinsically conducting polymers. They do not conduct extrinsically.
8. Which of the following is not true for intrinsically conducting polymers?
a) Low conductivities
b) Poor mechanical strength
c) Improcessability
d) Good storage stability
Answer: d
Clarification: Intrinsically conducting polymers have poor storage stability leading to its loss in conductivity.
9. Select the incorrect statement from the following option.
a) Conductive element filled polymer possess good bulk conductivity
b) Conductive element filled polymer are generally high in cost
c) Conductive element filled polymer are light in weight
d) Conductive element filled polymer are mechanically durable and strong
Answer: b
Clarification: Conductive element filled polymer are generally low in cost. All the other options are correct.
10. Which of the following is not an application of conducting polymers?
a) Rechargeable batteries
b) Analytical sensors
c) Electronics
d) Adhesives
Answer: d
Clarification: Rechargeable batteries, analytical sensors, electronics are some of the applications of conducting polymers.
11. Emeraldine base form of polyaniline is used as a resist for lithography.
a) True
b) False
Answer: a
Clarification: Emeraldine base form of polyaniline is used as a resist for lithography. The synthesis of polyaniline nano structures is facile.
12. Bakelite is ____________
a) Gel
b) Gas
c) Solid
d) Liquid
Answer: c
Clarification: Bakelite is soild. It is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde.