8247 + Mcqs in Chemical Engineering Page 97 McqOptions

4801.	Reactions with high activation energy are
A.	very temperature sensitive
B.	temperature insensitive
C.	always irreversible
D.	always reversible
Answer» B. temperature insensitive

Discussion

4802.	In case of a/an __________ chemical reaction, conversion increases with the rise in temperature.
A.	reversible exothermic
B.	irreversible exothermic
C.	irreversible endothermic
D.	reversible endothermic
Answer» E.

Discussion

4803.	A space velocity of 5 hr-1 means that
A.	five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour.
B.	after every 5 hours, reactor is being filled with the feed.
C.	cent per cent conversion can be achieved in at least 5 hours.
D.	a fixed conversion of a given batch of feed takes 5 hours.
Answer» B. after every 5 hours, reactor is being filled with the feed.

Discussion

4804.	The synthesis of proteins and metabolism in biological objects occur in the presence of biocatalyst called
A.	a ferment or an enzyme
B.	haemoglobin
C.	fungi
D.	none of these
Answer» D. none of these

Discussion

4805.	Kinetics of a catalytic reaction can be best studied on a/an __________ reactor.
A.	mixed
B.	integral (plug flow)
C.	differential (flow)
D.	either (a), (b) and (c).
Answer» E.

Discussion

4806.	In case of a __________ reactor, the composition in the reactor and at the exit of the reactor is the same.
A.	semi-batch
B.	tubular
C.	batch
D.	back-mix
Answer» E.

Discussion

4807.	Exothermic reactions are best carried out in
A.	a CSTR.
B.	CSTR in series.
C.	a plug flow reactor followed by CSTR.
D.	CSTR followed by a plug flow reactor.
Answer» E.

Discussion

4808.	The order of the chemical reaction, , whose rate equation is given as -rA = KCA2. CB is
A.	0
B.	1
C.	2
D.	3
Answer» E.

Discussion

4809.	What is the dispersion number for a plug flow reactor ?
A.	0
B.
C.	1
D.	-1
Answer» B.

Discussion

4810.	The decomposition of A into B is represented by the exothermic reaction, A 2B. To achieve maximum decomposition, it is desirable to carry out the reaction.
A.	at high P and high T.
B.	at low P and high T.
C.	at low P and low T.
D.	at high P and low T.
Answer» D. at high P and low T.

Discussion

4811.	The catalytic converter for conversion of SO2 to SO3 by contact process should have a feed with SO2 content between
A.	2-5%
B.	7-10%
C.	12-15%
D.	20-25%
Answer» C. 12-15%

Discussion

4812.	For all positive reaction orders for a particular duty,
A.	mixed reactor is always larger than the plug-flow reactor.
B.	ratio of the volume of the mixed reactor to that of the plug-flow reactor decreases with order.
C.	reactor size is independent of the type of flow.
D.	density variation during reaction affects design.
Answer» B. ratio of the volume of the mixed reactor to that of the plug-flow reactor decreases with order.

Discussion

4813.	The heat of reaction
A.	depends on the pressure only.
B.	depends on the mechanism of reaction only.
C.	depends on both pressure and mechanism of reaction.
D.	is independent of the mechanism of reaction.
Answer» E.

Discussion

4814.	Which of the following does not produce a change in the value of rate constant of a reaction ?
A.	Pressure
B.	Temperature
C.	Concentration and catalyst
D.	None of these.
Answer» D. None of these.

Discussion

4815.	For identical flow rate and feed composition, X plug flow reactors (PER) in series with a total volume V gives the same conversion as single
A.	CSTR of volume V
B.	PFR of volume V
C.	CSTR of volume V/X
D.	PFR of volume V/X
Answer» C. CSTR of volume V/X

Discussion

4816.	Time required for 50% decomposition of a liquid in an isothermal batch reactor following first order kinetics is 2 minutes. The time required for 75% decomposition will be about __________ minutes.
A.	3
B.	4
C.	6
D.	8
Answer» C. 6

Discussion

4817.	For a __________ order reaction, the units of rate constant and rate of reaction are the same.
A.	zero
B.	first
C.	second
D.	fractional
Answer» B. first

Discussion

4818.	In case of staged packed bed reactors carrying out exothermic reaction, use
A.	high recycle for pure gas.
B.	plug flow for dilute liquid requiring no large preheating of feed.
C.	cold shot operations for a dilute solution requiring large preheating to bring the stream upto the reaction temperature.
D.	all (a), (b) and (c).
Answer» E.

Discussion

4819.	Vegetable oils are hydrogenated in a __________ reactor.
A.	slurry
B.	plug flow
C.	homogeneous catalytic
D.	none of these
Answer» B. plug flow

Discussion

4820.	On application of pressure to the equilibrium system, ice water ; which of the following phenomenon will occur ?
A.	Water will evaporate
B.	Equilibrium will not be attained
C.	More ice will be formed
D.	More water will be formed.
Answer» E.

Discussion

4821.	Participation of __________ is involved in the occurrence of a chemical reaction.
A.	protons
B.	neutrons
C.	electrons
D.	none of these
Answer» D. none of these

Discussion

4822.	Promoter.
A.	initiates a chemical reaction and is a catalyst by itself.
B.	atlers the position of equilibrium in a reversible reaction.
C.	increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals.
D.	all (a), (b) and (c).
Answer» D. all (a), (b) and (c).

Discussion

4823.	A batch reactor suffers from following disadvantage.
A.	Poor product quality control.
B.	High labour and handling cost.
C.	High shutdown time requirement for emptying, cleaning and refilling.
D.	All (a), (b)and(c).
Answer» E.

Discussion

4824.	A first order reaction is to be treated in a series of two mixed reactors. The total volume of the two reactors is minimum, when the reactors are
A.	equal in size.
B.	of different sizes.
C.	of such size that the ratio of their volumes is < 5.
D.	none of these.
Answer» B. of different sizes.

Discussion

4825.	A second order liquid phase reaction, A B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume of the reacting mixture is V and the density of the liquid mixture is constant. The mass balance for A is
A.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/479-499-2.png">
B.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/479-499-1.png">
C.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/479-499-3.png">
D.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/479-499-4.png">
Answer» E.

Discussion

4826.	Half life period of a chemical reaction is proportional to CA0-1 , if the reaction is of __________ order.
A.	first
B.	zero
C.	second
D.	third
Answer» D. third

Discussion

4827.	The irreversible reaction, X Y, is the special case of the reversible reaction, X Y, in which the
A.	equilibrium constant is infinite.
B.	fractional conversion of 'A' at equilibrium is unity.
C.	concentration of 'A' at equilibrium is zero.
D.	all (a), (b) and (c).
Answer» E.

Discussion

4828.	An endothermic aqueous phase first order irreversible reaction is carried out in an adiabatic plug flow reactor. The rate of reaction
A.	is maximum at the inlet of the reactor.
B.	goes through a maximum along the length of the reactor.
C.	goes through a minimum along the length of the reactor.
D.	is maximum at the exit of the reactor.
Answer» B. goes through a maximum along the length of the reactor.

Discussion

4829.	For an ideal plug flow reactor, the value of Peclet number is
A.	0
B.
C.	1
D.	10
Answer» B.

Discussion

4830.	An endothermic second order reaction is carried out in an adiabatic plug flow reactor. The rate of heat generation is
A.	maximum at the inlet of the reactor.
B.	maximum at the exit of the reactor.
C.	maximum at the centre of the reactor.
D.	constant throughout the reactor.
Answer» B. maximum at the exit of the reactor.

Discussion

4831.	Equilibrium of a chemical reaction as viewed by kinetics is a __________ state.
A.	dynamic steady
B.	static steady
C.	dynamic unsteady
D.	none of these
Answer» B. static steady

Discussion

4832.	The conversion in a mixed reactor/accomplishing a reaction A 3R is 50% when gaseous reactant 'A' is introduced at the rate of 1 litre/second and the leaving flow rate is 2 litres/second. The holding time for this operation is __________ second.
A.	0.5
B.	1
C.	2
D.	3
Answer» B. 1

Discussion

4833.	The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor.
A.	greater than
B.	equal to
C.	smaller than
D.	unpredictable from the data
Answer» D. unpredictable from the data

Discussion

4834.	A space time of 3 hours for a flow reactor means that
A.	the time required to process one reactor volume of feed (measured at specified conditions) is 3 hours.
B.	three reactor volumes of feed can be processed every hour.
C.	it takes three hours to dump the entire volume of the reactor with feed.
D.	conversion is cent per cent after three hours.
Answer» B. three reactor volumes of feed can be processed every hour.

Discussion

4835.	The rate constant of a reaction depends on the
A.	initial concentration of reactants.
B.	time of reaction.
C.	temperature of the system.
D.	extent of reaction.
Answer» D. extent of reaction.

Discussion

4836.	For the reversible reaction A 2B, if the equilibrium constant K is 0.05 mole/litre; starting from initially 2 moles of A and zero moles of B, how many moles will be formed at equilibrium ?
A.	0.253
B.	0.338
C.	0.152
D.	0.637
Answer» C. 0.152

Discussion

4837.	The minimum energy required to allow a chemical reaction to proceed is termed as the 'threshold energy '. Chemical reaction with low activation energy are
A.	always irreversible.
B.	insensitive to temperature changes.
C.	mostly irreversible.
D.	highly temperature sensitive.
Answer» C. mostly irreversible.

Discussion

4838.	If Thiele modulus is __________ , then the pore diffusion resistance in a catalyst may be considered as negligible.
A.	0
B.
C.	< 0.5
D.	> 0.5
Answer» D. > 0.5

Discussion

4839.	From collison theory, the reaction rate constant is proportional to
A.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-428-1.png">
B.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-428-2.png">
C.	<span class="root"><i>T</i></span>
D.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-428-3.png">
Answer» E.

Discussion

4840.	For a mixed flow reactor operating at steady state, the rate of reaction is given by
A.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-427-1.png">
B.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-427-2.png">
C.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-427-3.png">
D.	<img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-427-4.png">
Answer» D. <img src="/_files/images/chemical-engineering/chemical-reaction-engineering/471-427-4.png">

Discussion

4841.	Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the
A.	activation energy
B.	equilibrium constant
C.	heat of reaction
D.	none of these
Answer» B. equilibrium constant

Discussion

4842.	The rate at which a chemical substance reacts is proportional to its
A.	active mass
B.	equivalent weight
C.	molecular weight
D.	none of these
Answer» B. equivalent weight

Discussion

4843.	The exit age distribution of a fluid leaving a vessel (denoted by E) is used to study the extent of non-ideal flow in the vessel. The value of is
A.	0
B.	1
C.
D.	<span class="root">2</span>
E.
Answer» C.

Discussion

4844.	A plug-flow reactor is characterised by
A.	high capacity.
B.	presence of axial mixing.
C.	presence of lateral mixing.
D.	constant composition and temperature of reaction mixture.
Answer» D. constant composition and temperature of reaction mixture.

Discussion

4845.	Three plug flow reactors (PFR's) of 4, 5 & 6 m3 volumes are arranged in two branches as shown below in the figure.If the total feed rate is 300 tons/hr, then for the same conversion in each branch, the feed rate through branch II should be __________ tons/hr.
A.	100
B.	150
C.	200
D.	225
Answer» B. 150

Discussion

4846.	For a tubular reactor with space time ' ' and residence time ' ', the following statement holds good.
A.	and are always equal.
B.	= , when the fluid density changes in the reactor.
C.	= , for an isothermic tubular reactor in which the density of the process fluid is constant.
D.	= , for a non-isothermal reactor.
Answer» D. = , for a non-isothermal reactor.

Discussion

4847.	Exposure of a photographic plate to produce a latent image is an example of __________ reaction.
A.	very slow
B.	very fast
C.	photochemical
D.	both (b) and (c)
Answer» E.

Discussion

4848.	For identical flow rate, feed composition and for elementary first order reactions, 'N' equal sized mixed reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for constant density systems. This is true, when the value of 'N' is
A.	1
B.	>1
C.
D.	1
Answer» D. 1

Discussion

4849.	An imbalanced chemical reaction equation is against the law of
A.	multiple proportion
B.	conservation of mass
C.	constant proportion
D.	none of these
Answer» C. constant proportion

Discussion

4850.	For the chemical reaction P Q, it is found that the rate of reaction doubles as the concentration of 'P' is doubled. If the reaction rate is proportional to Cpn, then what is the value of 'n' for this chemical reaction ?
A.	1
B.	2
C.	3
D.	0
Answer» B. 2

Discussion

Explore topic-wise MCQs in Engineering.

Reactions with high activation energy are

In case of a/an __________ chemical reaction, conversion increases with the rise in temperature.

A space velocity of 5 hr-1 means that

The synthesis of proteins and metabolism in biological objects occur in the presence of biocatalyst called

Kinetics of a catalytic reaction can be best studied on a/an __________ reactor.

In case of a __________ reactor, the composition in the reactor and at the exit of the reactor is the same.

Exothermic reactions are best carried out in

The order of the chemical reaction, , whose rate equation is given as -rA = KCA2. CB is

What is the dispersion number for a plug flow reactor ?

The decomposition of A into B is represented by the exothermic reaction, A 2B. To achieve maximum decomposition, it is desirable to carry out the reaction.

The catalytic converter for conversion of SO2 to SO3 by contact process should have a feed with SO2 content between

For all positive reaction orders for a particular duty,

The heat of reaction

Which of the following does not produce a change in the value of rate constant of a reaction ?

For identical flow rate and feed composition, X plug flow reactors (PER) in series with a total volume V gives the same conversion as single

Time required for 50% decomposition of a liquid in an isothermal batch reactor following first order kinetics is 2 minutes. The time required for 75% decomposition will be about __________ minutes.

For a __________ order reaction, the units of rate constant and rate of reaction are the same.

In case of staged packed bed reactors carrying out exothermic reaction, use

Vegetable oils are hydrogenated in a __________ reactor.

On application of pressure to the equilibrium system, ice water ; which of the following phenomenon will occur ?

Participation of __________ is involved in the occurrence of a chemical reaction.

Promoter.

A batch reactor suffers from following disadvantage.

A first order reaction is to be treated in a series of two mixed reactors. The total volume of the two reactors is minimum, when the reactors are

Half life period of a chemical reaction is proportional to CA0-1 , if the reaction is of __________ order.

The irreversible reaction, X Y, is the special case of the reversible reaction, X Y, in which the

An endothermic aqueous phase first order irreversible reaction is carried out in an adiabatic plug flow reactor. The rate of reaction

For an ideal plug flow reactor, the value of Peclet number is

An endothermic second order reaction is carried out in an adiabatic plug flow reactor. The rate of heat generation is

Equilibrium of a chemical reaction as viewed by kinetics is a __________ state.

The conversion in a mixed reactor/accomplishing a reaction A 3R is 50% when gaseous reactant 'A' is introduced at the rate of 1 litre/second and the leaving flow rate is 2 litres/second. The holding time for this operation is __________ second.

The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor.

A space time of 3 hours for a flow reactor means that

The rate constant of a reaction depends on the

For the reversible reaction A 2B, if the equilibrium constant K is 0.05 mole/litre; starting from initially 2 moles of A and zero moles of B, how many moles will be formed at equilibrium ?

The minimum energy required to allow a chemical reaction to proceed is termed as the 'threshold energy '. Chemical reaction with low activation energy are

If Thiele modulus is __________ , then the pore diffusion resistance in a catalyst may be considered as negligible.

From collison theory, the reaction rate constant is proportional to

For a mixed flow reactor operating at steady state, the rate of reaction is given by

Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the

The rate at which a chemical substance reacts is proportional to its

The exit age distribution of a fluid leaving a vessel (denoted by E) is used to study the extent of non-ideal flow in the vessel. The value of is

A plug-flow reactor is characterised by

Three plug flow reactors (PFR's) of 4, 5 &amp; 6 m3 volumes are arranged in two branches as shown below in the figure.If the total feed rate is 300 tons/hr, then for the same conversion in each branch, the feed rate through branch II should be __________ tons/hr.

For a tubular reactor with space time ' ' and residence time ' ', the following statement holds good.

Exposure of a photographic plate to produce a latent image is an example of __________ reaction.

For identical flow rate, feed composition and for elementary first order reactions, 'N' equal sized mixed reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for constant density systems. This is true, when the value of 'N' is

An imbalanced chemical reaction equation is against the law of

For the chemical reaction P Q, it is found that the rate of reaction doubles as the concentration of 'P' is doubled. If the reaction rate is proportional to Cpn, then what is the value of 'n' for this chemical reaction ?

Three plug flow reactors (PFR's) of 4, 5 & 6 m3 volumes are arranged in two branches as shown below in the figure.If the total feed rate is 300 tons/hr, then for the same conversion in each branch, the feed rate through branch II should be __________ tons/hr.