Engineering Chemistry Questions and Answers for Freshers focuses on “Elastomers – 2”.
1. Which of the following act as a catalyst in the preparation of Buna-S?
a) Benzoyl peroxide
b) Hydrogen peroxide
c) Cumene hydroperoxide
d) Acrylonitrile
Answer: c
Clarification: Cumene hydroperoxide act as a catalyst in the preparation of Buna-S (Butadiene styrene).
2. Which of the following statement is incorrect about the SBR?
a) It has low load bearing capacity
b) It has high abrasion resistance
c) It swells in oils and solvents
d) It has low oxidation resistance
Answer: a
Clarification: SBR has high load bearing capacity, high abrasion resistance, swells in oil and solvent and has low oxidation resistance.
3. Which of the following is an application of SBR?
a) Conveyor belts for food
b) Lining of tanks
c) Oil-resistance foam
d) Printing rollers
Answer: b
Clarification: Lining of tanks, adhesives, gaskets, motor tyres, etc are some of the applications of SBR.
4. Buna-N is prepared by co-polymerisation of butadiene and acrylonitrile in the emulsion system.
a) True
b) False
Answer: a
Clarification: Buna-N is prepared by the co-polymerisation of butadiene and acrylonitrile in the emulsion system. Buna-N is nitrile rubber used in the automotive and aeronautical industry to make fuel and oil handling hoses.
5. Which of the following has the best resistance to oils?
a) Natural rubber
b) Neoprene
c) Nitrile rubber
d) Styrene rubber
Answer: c
Clarification: Nitrile rubber has the best resistance to oils among the following options. All the other options have lower resistance to oils.
6. Which of the following is not an application of neoprene?
a) Conveyor belts
b) Wire and cable insulation
c) Adhesives
d) Printing rollers
Answer: d
Clarification: Conveyor belts, adhesives, wire and cable insulation, shoe-soles, etc are some of the applications of neoprene. Printing rollers is not an application of neoprene.
7. The major constituent of butyl rubber is ____________
a) Isobutylene
b) Isoprene
c) Chloroprene
d) Acrylonitrile
Answer: a
Clarification: In butyl rubber, isobutylene constitutes (95-99) % and isoprene constitutes (1-5) %.
8. Which of the following act as a catalyst in the preparation of butyl rubber?
a) Cumene hydroperoxide
b) Anhydrous AlCl3
c) Lewis base
d) Grignard reagent
Answer: b
Clarification: Anhydrous AlCl3 acts as a catalyst in the preparation of butyl rubber. Butyl rubber is a synthetic rubber, a co-polymer of isobutylene with isoprene.
9. The solvent used in the preparation of butyl rubber is ____________
a) Methyl iodide
b) Methyl halide
c) Methyl chloride
d) Methyl sulphide
Answer: c
Clarification: The solvent used in the preparation of butyl rubber is methyl chloride. Butyl rubber is a synthetic rubber, a copolymer of isobutylene with isoprene.
10. Because of its hydrocarbon nature, butyl rubber is soluble in hydrocarbon solvents but has excellent resistance to polar solvents like alcohol and acetone.
a) True
b) False
Answer: a
Clarification: Because of its hydrocarbon nature, butyl rubber is soluble in hydrocarbon solvents but has excellent resistance to polar solvents like alcohol and acetone. Butyl rubber and halogenated rubber are used for the inner liner that holds the air in the tire.
areas of Engineering Chemistry for Freshers,