Engineering Questions with Answers - Multiple Choice Questions
Chemical Industry MCQ’s – Synthetic Organic Chemical – Styrene
1 - Question
Which process is used for the manufacture of styrene?
a) Dehydrogenation of ethyl benzene
b) Hydrogenation of acetophenone
c) Hydrogenation of toluene
d) Benzene sulphurated process
View Answer
Explanation: Styrene is manufactured first by alkylation of benzene followed by dehydrogenation of ethyl benzene. Hydrogenation of toluene is used for the manufacture of benzene.
2 - Question
Benzene is alkylated with ethylene for the manufacture of styrene.
a) True
b) False
View Answer
Explanation: Benzene is alkylated with ethylene by Friedel craft method using aluminum chloride or any other acid type catalyst.
3 - Question
Alkylation in manufacture of styrene must be done under wet condition.
a) True
b) False
View Answer
Explanation: Alkylation operation must be done under very dry conditions with high purity feed stock to avoid activity loss of the catalyst. All benzene feed must be dry by azeotropic distillation.
4 - Question
How is crude acidic ethyl benzene is neutralized in the manufacture of styrene?
a) Adding HCl
b) Adding H2SO4
c) Adding NaOH
d) Adding NaCl
View Answer
Explanation: Crude acidic ethyl benzene from the coolers is neutralized with 50% NaOH solution stripped to remove polyethyl benzene and the overhead is sent to the benzene column which separates wet benzene from ethyl benzene.
5 - Question
How is traces of tar and Sulphur removed from styrene?
a) O-tertiary catechol
b) P-tertiary catechol
c) NaOH
d) KOH
View Answer
Explanation: The styrene which was stabilized with p-tertiary catechol is vacuumed distilled to remove traces of tar and Sulphur. The final overhead is refrigerated at 10 degree Celsius.