Engineering Questions with Answers - Multiple Choice Questions

Unit Processes MCQ’s – Reactions

1 - Question

Back mixing can occur only in _________ in a chemical process.
a) Stagnant reaction
b) Flow reaction
c) Both the reactions
d) Does not depend on it
View Answer Answer: b
Explanation: Back mixing is the mixing of reactants and products due to flow reaction. It happens in horizontal direction and it reduces the product quality.



2 - Question

How many types of reactors are there?
a) 2
b) 3
c) 4
d) Many number
View Answer Answer: c
Explanation: There are 4 types of reactors: simple batch homogeneous, semi batch, Continuous homogeneous and continuous heterogeneous reactors.



3 - Question

In which reactor one reactant is feed and other reactant is added continuously?
a) Simple batch reactor
b) Semi batch reactor
c) Continuous homogeneous reactor
d) Continuous heterogeneous reactor
View Answer Answer: b
Explanation: In Semi batch reactor, it is a type of reactor in which one reactant is already added and another one is continuously added.



4 - Question

When a large volume is there, what type of reactor is used?
a) Tubular reactor
b) Simple batch reactor
c) Semi batch reactor
d) Tower reactor
View Answer Answer: d
Explanation: Whenever a large volume is there for reaction we use tower reactor. It further consists of empty, packed and baffled tower reactors.



5 - Question

Which tower has a horizontal tank, with low ratio of length to diameter?
a) Baffled tank reactor
b) Tower reactor
c) Longitudinal reactor
d) All of the mentioned
View Answer Answer: a
Explanation: Only baffled tank has a low length to diameter ratio, and is horizontal in shape.



6 - Question

Which reactor has zero back mixing?
a) Tubular reactor
b) Longitudinal reactor
c) Semi batch reactor
d) All of the mentioned
View Answer Answer: b
Explanation: Only longitudinal reactor has zero back mixing as the reaction takes place only in one direction and not laterally.



7 - Question

What %cent age back mixing takes place in a Stirred tank reactor?
a) 100%
b) 75%
c) 50%
d) 0%
View Answer Answer: a
Explanation: Only in a Stirred tank reactor we get 100% back mixing. Hence is has a very low yield.



8 - Question

What is the other name of series reaction?
a) Complex reaction
b) Parallel reaction
c) Consecutive reaction
d) None of the mentioned
View Answer Answer: c
Explanation: The other name of Series reaction is Consecutive reaction.



9 - Question

For a large scale production, which reactor is preferable?
a) Batch reactor
b) Semi batch reactor
c) Continuous reactor
d) None of the mentioned
View Answer Answer: c
Explanation: For a large amount of production i.e high yield, a continuous reactor is always preferred.



10 - Question

For a high degree of agitation, which reactor is used?
a) Stirred tank
b) Tubular reactor
c) Longitudinal reactor
d) All of the mentioned
View Answer Answer: a
Explanation: For high amount of agitation a stirred tank is used because it provides fast reaction. Mechanical agitators are employed in it to provide agitation.

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