Elastomers – Biochemical Engineer MCQs

By: Prof. Dr. Fazal Rehman | Last updated: November 23, 2024

1. The amount of sulphur that is added always determines the extent of the stiffness of vulcanised rubber.
(A). False
(B). True
(E). None of these
Answer: b

2. Which of the following is the tensile strength (kg/cm²) of vulcanised rubber?
(A). 200
(B). 5000
(C). 500
(D). 2000
(E). None of these
Answer: d

3. Which of the following is the percentage of butadiene and styrene in Buna-S?
(A). 75% and 25% respectively
(B). 60% and 40% respectively
(C). 80% and 20% respectively
(D). 50% each
(E). None of these
Answer: a

4. The application of SBR is ____________
(A). Conveyor belts for food
(B). Printing rollers
(C). Oil-resistance foam
(D). Lining of tanks
(E). None of these
Answer: d

5. __________ act as a catalyst in preparation of Buna-S.
(A). Cumene hydroperoxide
(B). Hydrogen peroxide
(C). Benzoyl peroxide
(D). Acrylonitrile
(E). None of these
Answer: a

6. The Buna-N is always prepared by the co-polymerisation of the butadiene and acrylonitrile in an emulsion system.
(A). False
(B). True
(E). None of these
Answer: b

7. ___________ has the best resistance to oils.
(A). Nitrile rubber
(B). Neoprene
(C). Natural rubber
(D). Styrene rubber
(E). None of these
Answer: a

8. ____________ act as a catalyst in the preparation of butyl rubber.
(A). Anhydrous AlCl₃
(B). Cumene hydroperoxide
(C). Lewis base
(D). Grignard reagent
(E). None of these
Answer: a

9. The statement that is incorrect about the SBR is __________.
(A). This has high abrasion resistance
(B). This has low load-bearing capacity
(C). This swells in oils and solvents
(D). This has low oxidation resistance
(E). None of these
Answer: b

10. Which of the following is the solvent that is used in the preparation of butyl rubber?
(A). Methyl iodide
(B). Methyl halide
(C). Methyl sulphide
(D). Methyl chloride
(E). None of these
Answer: d

11. Which of the following is the major constituent of butyl rubber?
(A). Chloroprene
(B). Isoprene
(C). Isobutylene
(D). Acrylonitrile
(E). None of these
Answer: c

12. The butyl rubber is always soluble in the hydrocarbon solvents but has excellent resistance to the polar solvents like alcohol and acetone due to its hydrocarbon nature.
(A). False
(B). True
(E). None of these
Answer: b

13. Which of the following is the Natural rubber?
(A). Acrylonitrile
(B). Ethylene glycol
(C). Butadiene
(D). Polyisoprene
(E). None of these
Answer: d

14. Not the essential structural requirement of an elastomer is ______________.
(A). Rigidity in structure
(B). Weak intermolecular forces
(C). Long flexible chains
(D). Occasional cross-linking
(E). None of these
Answer: a

15. Not an application of neoprene is ____________.
(A). Conveyor belts
(B). Wire and cable insulation
(C). Printing rollers
(D). Adhesives
(E). None of these
Answer: c

16. In the vulcanisation process, with which of the following the raw rubber is heated?
(A). Oxygen
(B). Calcium
(C). Carbon
(D). Sulphur
(E). None of these
Answer: d

17. Which of the following is the structural formula of isoprene?
(A). 2-benzyl-1,3-butadiene
(B). 3-benzyl-1,2-butadiene
(C). 2-methyl-1,3-butadiene
(D). 3-methyl-1,2-butadiene
(E). None of these
Answer: c

18. At which of the following temperature the raw rubber is heated for the vulcanisation process?
(A). 0-10°C
(B). 10-50°C
(C). 100-140°C
(D). 50-100°C
(E). None of these
Answer: c

19. Which of the following is the incorrect statement?
(A). Raw rubber is durable
(B). Raw rubber is attacked by oxidizing agent
(C). In the organic solvents, it always undergoes the swelling and disintegration
(D). The Raw rubber is always weak and has very low tensile strength
(E). None of these
Answer: a

20. The incorrect statement is that the Vulcanised rubber has ______________.
(A). High elasticity
(B). Only slight tackiness
(C). Excellent resilience
(D). Tensile strength 10 times more than raw rubber
(E). None of these
Answer: a