Engineering Questions with Answers - Multiple Choice Questions
Chemical Technology MCQ’s – C3 Compounds – Isoprene
1 - Question
Which among the following methods is not used for the manufacture of isoprene?
a) Isomerization of propylene dimer
b) Isobutylene formaldehyde reaction
c) Methyl ethyl ketone formaldehyde reaction
d) Ethylene cyanohydrin pyrolysis
View Answer
Explanation: Ethylene cyanohydrin pyrolysis is done for the manufacture of industrial acrylonitrile whereas Isomerization of propylene dimer, Isobutylene formaldehyde reaction and Methyl ethyl ketone formaldehyde reaction is done for the manufacture of isoprene.
2 - Question
Which catalyst is used in the manufacture of isoprene by isomerization of propylene dimer?
a) Triethyl aluminium
b) Trimethyl aluminium
c) Triphenyl aluminium
d) Tripropyl aluminium
View Answer
Explanation: A compressed propylene is reacted with tripropyl aluminium catalyst along with a carrier solvent at 200atms pressure in a reactor filled with heat transfer surface to remove exothermic heat of reaction.
3 - Question
Isoprene can be polymerized with a stereospecific catalyst. True or false?
a) True
b) False
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Explanation: Isoprene can be polymerized with a stereospecific catalyst and a range of cis-4-polybutadiene-polyisoprene elastomer bends can be manufactured.
4 - Question
What are the series of chemical reactions in manufacture of isoprene from isomerization of polypropylene dimer?
a) Dimerization-Isomerization-Pyrolysis
b) Pyrolysis-Isomerization-Dimerization
c) Dimerization-Pyrolysis-Isomerization
d) Pyrolysis-Dimerization-Isomerization
View Answer
Explanation: Initially propylene is dimerized using tripropyl aluminium as catalyst which forms 2-methyl-1-pentene which further on isomerization forms 2-methyl-2-pentene and finally undergoes pyrolysis to form isoprene.
5 - Question
What kind of a catalyst is used in the packed bed reactor of isomerization section in the manufacture of isoprene from isomerization of polypropylene dimer?
a) Neutral type catalyst
b) Solid catalyst
c) Acid type catalyst
d) Gas type catalyst
View Answer
Explanation: Isomerization occurs in a packed bed reactor containing an acid type catalyst. Process conditions range from 150-300 ° with liquid velocity of 15 to .5 m/s.