Engineering Questions with Answers - Multiple Choice Questions
Unit Processes MCQ’s – Types of Alkylation
1 - Question
The alkylation of hydrocarbons is referred as which type of alkylation?
a) Substitution of hydroxy group
b) Alkyl metallic compound
c) Substitution for hydrogen
d) None of the mentioned
View Answer
Explanation: the substitution of an alkyl group for hydrogen in carbon compounds, this type of alkylation is frequently referred to as alkylation of hydrocarbons, and many of the instances are nuclear alkylations.
2 - Question
When aniline is alkylated, how does the alkyl group react?
a) Nuclearly
b) At the nitrogen atom
c) Nuclearly & At the nitrogen atom
d) None of the mentioned
View Answer
Explanation: When aniline is alkylated, the alkyl group can react in many cases either nuclearly or at the nitrogen atom, depending mainly on the operating conditions.
3 - Question
Which compounds decompose readily into free alkyl radicals?
a) Peroxides
b) Phenol
c) Aromatic
d) All of the mentioned
View Answer
Explanation: Compounds which decompose readily into free alkyl radicals such as peroxides, mercaptans, etc., will alkylate hydrocarbons.
4 - Question
Which methyl radical has the highest affinity to attack an aromatic?
a) Diphenyl ether
b) Quinoline
c) Benzene
d) Anthracene
View Answer
Explanation: The affinity of the methyl radical to attack an aromatic increases in the following order: benzene, diphenyl ether, pyridine, diphenyl, benzophenone, naphthalene, quinoline, phenanthrene, pyrene, and anthracene.
5 - Question
Which of the following reacts least with isopropyl benzene?
a) Methyl
b) Tertiary butyl
c) Propyl
d) Isopropyl
View Answer
Explanation: The ability of free alkyl radicals to interact with isopropyl benzene and cyclohexene decreases in the following order: methyl, ethyl, propyl, butyl, isopropyl, sec-butyl, and tertiary butyl.
6 - Question
Which type of catalyst are used for Olefin Alkylation of Aromatics?
a) Friedel-Crafts type
b) Protonic acid
c) Friedel-Crafts type & Protonic acid
d) None of the mentioned
View Answer
Explanation: Olefin Alkylation of Aromatics. Benzene, toluene, xylenes, naphthalene, and phenols are aromatics which are commonly alkylated. Either Friedel-Crafts type or protonic acid catalysts are normally used.
7 - Question
The aliphatic ethers are made by the action of which acid on alcohol?
a) Nitric acid
b) Sulphuric acid
c) Hydrochloric acid
d) All of the mentioned
View Answer
Explanation: The aliphatic ethers used in industry are made usually by the action of sulfuric acid on an alcohol.
8 - Question
The alkaloid reaction takes place in presence of what?
a) Primary nitrogen
b) Secondary nitrogen
c) Tertiary nitrogen
d) None of the mentioned
View Answer
Explanation: Some of the most difficult oxygen alkylations are those involving the alkaloids, where the alkylation is often carried out to replace the hydrogen of the hydroxyl group in the presence of the tertiary nitrogen of the alkaloid.
9 - Question
For the higher amines, which phase is used so that reaction takes place?
a) Liquid
b) Vapour
c) Solid
d) None of the mentioned
View Answer
Explanation: For the higher amines, the action of an alkyl halide on ammonia in the liquid phase, often in the presence of the corresponding alcohol, is frequently used.
10 - Question
Aniline can also be alkylated in the vapour phase.
a) True
b) False
View Answer
Explanation: Aniline can also be alkylated in the vapour phase at temperatures of about 400°C .using methanol, dimethyl ether, ethyl alcohol, and diethyl ether.
11 - Question
Heterocyclic amines can be alkylated with alkyl halides.
a) True
b) False
View Answer
Explanation: Heterocyclic amines can be alkylated with alkyl halides or with alcohols in the presence of hydrogen plus a nickel catalyst.