Chemical Reaction Engineering Mcqs

Q:

With an accumulation of waste formed during the reaction, the value of observed Monod rate constant ____

A) Decreases B) Increases
C) Remains constant D) First decreases and then increases
 
Answer & Explanation Answer: A) Decreases

Explanation: The accumulation of waste formed decelerates the reaction rate. This decrease is reflected in the reaction rate constant.

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15
Q:

The hierarchy of phases for the microbes in a fermentation process is ____

A) Exponential growth phase → Lag phase → Stationary phase → Death phase B) Stationary phase → Lag phase → Exponential growth phase → Death phase
C) Lag phase → Exponential growth phase → Stationary phase → Death phase D) Lag phase → Stationary phase → Exponential growth phase → Death phase
 
Answer & Explanation Answer: C) Lag phase → Exponential growth phase → Stationary phase → Death phase

Explanation: There is an initial lag phase for the microbial cells to begin growth and reproduction. The cells then grow exponentially and there exists a stationary growth less phase. Eventual death of cells is observed due to depletion of food.

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18
Q:

State true or false.
Kinetics of microbial fermentation cannot be expressed by Monod kinetics.

A) True B) False
 
Answer & Explanation Answer: B) False

Explanation: Not available for this question

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25
Q:

If τ² = 100 and σ² = 10, the number of tanks necessary to model a real reactor as N ideal tanks in series is ____

A) 1 B) 10
C) 5 D) 100
 
Answer & Explanation Answer: B) 10

Explanation: Not available for this question

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23
Q:

According to tanks in series model, the spread of the tracer curve is proportional to ____

A) Square of distance from the tracer origin B) Square root of distance from the tracer origin
C) Cube of distance from the tracer origin D) Inverse square of distance from the tracer origin
 
Answer & Explanation Answer: B) Square root of distance from the tracer origin

Explanation: Not available for this question

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30
Q:

State true or false.
The tank in series model depicts a non – ideal tubular reactor as a series of equal sized CSTRs.

A) True B) False
 
Answer & Explanation Answer: A) True

Explanation: A number of tanks in series represent a PFR. Any CSTR behaves like a PFR if its volume is reduced. Infinite CSTRs are connected in series to approach PFR behaviour.

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24
Q:

State true or false.
The tank in series model is a single parameter model.

A) False B) True
 
Answer & Explanation Answer: B) True

Explanation: The tank in series model is used to represent non – ideal flow in PFR. It is a one parameter model and the parameter is the number of tanks.

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23
Q:

The variance of a CSTR is ____

A) 1 B) 0
C) ∞ D) -1
 
Answer & Explanation Answer: C) ∞

Explanation: There is complete mixing inside a CSTR. The reactants are uniformly mixed. Hence, there is a variation in CSTR.

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