1443 + Mcqs in Chemical Reaction Engineering Page 13 McqOptions

601.	_A pollutant P degrades according to first order kinetics. An aqueous stream containing P at 2 kmole/m¬¨‚â• and volumetric flow rate 1m¬¨‚â• /h requires a mixed flow reactor of volume V to bring down the pollutant level to 0.5 kmole/m¬¨‚â• . The inlet concentration of the pollutant is now doubled and the volumetric flow rate is tripled. If the pollutant level is to be brought down to the same level of 0.5 kmole/m¬¨‚â• , the volume of the mixed flow reactor should be increased by a factor of$?
A.	7
B.	6
C.	3
D.	7/3
Answer» B. 6

Discussion

602.	_Backmixing is most predominant in$?
A.	A well stirred batch reactor
B.	A plug-flow reactor
C.	A single CSTR
D.	CSTR's connected in series
Answer» D. CSTR's connected in series

Discussion

603.	_If the time required to change the concentration of reactant to half its original value is independent of the initial concentration, the order of reaction is$?
A.	Zero
B.	One
C.	Two
D.	Three
Answer» C. Two

Discussion

604.	_Which of the following is not endothermic in nature?$?
A.	Combustion of sulphur
B.	Gasification of carbon
C.	Thermal cracking of fuel oil
D.	Steam reforming of naphtha
Answer» B. Gasification of carbon

Discussion

605.	_In autocatalytic reactions,$?
A.	One of the reactants acts as a catalyst
B.	One of the products acts as a catalyst
C.	Catalysts have very high selectivity
D.	No catalyst is used
Answer» C. Catalysts have very high selectivity

Discussion

606.	_The role of a catalyst in a chemical reaction is to change the$?
A.	Equilibrium constant
B.	Activation energy
C.	Final products
D.	Heat of reaction
Answer» C. Final products

Discussion

607.	_Which of the following factors control the design of a fluid-solid reactor?$?
A.	Reaction kinetics for single particle,
B.	Size distribution of solids beingtreated
C.	Flow patterns of solids and fluid in the reactor
D.	All of the above
Answer» E.

Discussion

608.	_In chamber process of sulphuric acid manufacture in industry, the gas phase oxidation of SO‚Äö√á√á to SO‚Äö√á√â is accomplished by a __________ reaction.$?
A.	Non-catalytic homogeneous
B.	Non-catalytic heterogeneous
C.	Catalytic homogenous
D.	Catalytic heterogeneous
Answer» D. Catalytic heterogeneous

Discussion

609.	_Pick the WRONG design guideline for a reactor in which the reactions, A ‚Äö√ú√≠ R (desired) and A ‚Äö√ú√≠ S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k‚Äö√á√Ö/k‚Äö√á√á).Csub>Aa-b$?
A.	Use high pressure and eliminate inerts, when a > b
B.	Avoid recycle, when a > b
C.	Use batch reactor or plug flow reactor, when a > b
D.	Use CSTR with a high conversion, when a > b
Answer» C. Use batch reactor or plug flow reactor, when a > b

Discussion

610.	_Chemical kinetics can predict the __________ of a chemical reaction.$?
A.	Rate
B.	Feasibility
C.	Both A & B
D.	Neither A nor B
Answer» B. Feasibility

Discussion

611.	_A backmix reactor$?
A.	Is same as plug-flow reactor
B.	Is same as ideal stirred tank reactor
C.	Employs mixing in axial direction only
D.	Is most suitable for gas phase reaction
Answer» C. Employs mixing in axial direction only

Discussion

612.	_The fractional volume change between no conversion and complete conversion, for the isothermal gas phase reaction, 2A ‚Äö√ú√≠ R, is$?
A.	0.5
B.	-0.5
C.	1
D.	1.5
Answer» C. 1

Discussion

613.	_Catalyst carriers$?
A.	Have very high selectivity
B.	Increase the activity of a catalyst
C.	Provide large surface area with a small amount of active material
D.	Inhibit catalyst poisoning
Answer» D. Inhibit catalyst poisoning

Discussion

614.	_A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction.$?
A.	Less than
B.	Equal to
C.	More than
D.	Equal to or more than
Answer» E.

Discussion

615.	_The optimum performance for reactors operating in parallel is obtained when the feed stream is distributed in such a way, that the$?
A.	Space time for each parallel line is same
B.	Space time for parallel lines is different
C.	Larger reactors have more space time compared to smaller ones
D.	None of these
Answer» B. Space time for parallel lines is different

Discussion

616.	_Consider the 'n' th order irreversible liquid phase reaction A ‚Äö√ú√≠ B. Which one of the following plots involving half life of the reaction (t1/2) and the initial reactant concentration (CA0) gives a straight line plot?$?
A.	CA0 Vs t1/2
B.	Ln CA0 Vs t1/2
C.	CA0 Vs ln t1/2
D.	Ln CA0 Vs ln t1/2
Answer» D. Ln CA0 Vs ln t1/2

Discussion

617.	_Pick out the wrong statement pertaining to space velocity of flow reactors.$?
A.	The unit of space velocity is (time)‚Äö√Ö¬™¬¨œÄ
B.	The space velocity of 3 hr‚Äö√Ö¬™¬¨œÄ means that three reactor volumes of feed at specified conditions are being fed into the reactor every hour
C.	The space velocity of 3 hr‚Äö√Ö¬™¬¨œÄ means that one third reactor volume of feed at specified conditions are being fed into the reactor
D.	None of these
Answer» D. None of these

Discussion

618.	_The rate of reaction of a/an __________ reaction is not affected by temperature rise.$?
A.	Autocatalytic
B.	Photochemical
C.	Consecutive
D.	Zero order
Answer» C. Consecutive

Discussion

619.	_The experimentally determined overall order of the reaction, A + B ‚Äö√ú√≠ C + D, is two. Then the$?
A.	Reaction is elementary with a molecularity of 2
B.	Molecularity of the reaction is 2, but the reaction may not be elementary
C.	Reaction may be elementary with molecularity of 2
D.	Reaction is elementary but the molecularity may not be 2
Answer» B. Molecularity of the reaction is 2, but the reaction may not be elementary

Discussion

620.	_A Catalyst$?
A.	Increases the equilibrium concentration of the product
B.	Changes the equilibrium constant of the reaction
C.	Shortens the time to reach the equilibrium
D.	None of these
Answer» D. None of these

Discussion

621.	_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

622.	_If in the gaseous phase reaction, N‚Äö√á√áO‚Äö√á√ë ‚Äö√°√£ 2NO‚Äö√á√á, x is the part of N‚Äö√á√áO‚Äö√á√ë which dissociates, then the number of molecules at equilibrium will be$?
A.	(1 + x)
B.	(1 - x)
C.	(1 + x)¬¨‚â§
D.	(1 - x)¬¨‚â§
Answer» B. (1 - x)

Discussion

623.	_Given, 3H‚Äö√á√á + CO = CH‚Äö√á√ë + H‚Äö√á√áO, KP = 101.84 and, 4H‚Äö√á√á + CO‚Äö√á√á = CH‚Äö√á√ë + 2H‚Äö√á√áO, KP = 101.17the KP for the reaction CO + H‚Äö√á√áO = CO‚Äö√á√á + H‚Äö√á√á is$?
A.	103.01
B.	10-0.67
C.	10-3.01
D.	L00.67
Answer» E.

Discussion

624.	___________ catalytic reaction is involved in the thermal cracking of gas oil.$?
A.	Homogeneous
B.	Homogeneous non
C.	Heterogeneous
D.	Heterogeneous non
Answer» B. Homogeneous non

Discussion

625.	_The value of 'n' for a chemical reaction A ‚Äö√ú√≠ B, whose reaction rate is ‚Äö√ú√≠ CAn, will be __________ if the rate of the reaction increases by a factor of 8, when the concentration of is doubled.$?
A.	0
B.	1
C.	2
D.	3
Answer» E.

Discussion

626.	_A second order reaction of the form A + B ‚Äö√ú√≠ C is called a pseudo-first order reaction, when$?
A.	CA0 = CB0
B.	CA0 > CB0
C.	CB0 > CA0
D.	CB0 ‚Äö√¢‚Ä¢ CB0
Answer» E.

Discussion

627.	_Slurry reactors are characterised by the$?
A.	Lack of intraparticle diffusion resistance
B.	Presence of two mobile phases
C.	Both A and B
D.	Neither A nor B
Answer» D. Neither A nor B

Discussion

628.	_Space time equals the mean residence time$?
A.	When the density of the reaction mixture is constant
B.	For large diameter tubular reactor
C.	For narrow diameter tubular reactor
D.	For CSTR
Answer» B. For large diameter tubular reactor

Discussion

629.	_Transition state theory relates the above quantities as$?
A.	K ‚Äö√ √π e-E/RT
B.	K ‚Äö√ √π T.eE/RT
C.	K ‚Äö√ √π ‚Äö√ √∂T
D.	K ‚Äö√ √π T1.5
Answer» C. K ‚Äö√ √π ‚Äö√ √∂T

Discussion

630.	n' number of plug flow reactors (P.F.R) in series with a total volume 'V' gives the same conversion as one P.F.R. of volume$?
A.	V/n
B.	V
C.	V.n
D.	1/V
Answer» C. V.n

Discussion

631.	In an ideal mixed reactor (at steady state), the$?
A.	Space time is equivalent to holding time for constant density systems
B.	Composition throughout the reactor remains same
C.	Exit stream has the same composition as the fluid within the reactor
D.	All of the above
Answer» E.

Discussion

632.	The performance equations for constant density systems are identical for$?
A.	P.F.R. and backmix reactor
B.	P.F.R. and batch reactor
C.	P.F.R, batch reactor and backmix reactor
D.	Batch reactor and backmix reactor
Answer» C. P.F.R, batch reactor and backmix reactor

Discussion

633.	Shift conversion reaction$?
A.	Converts N‚Äö√á√á and H‚Äö√á√á into NH‚Äö√á√â
B.	Converts CO to CO‚Äö√á√á with steam
C.	Is non-catalytic
D.	Is highly exothermic
Answer» C. Is non-catalytic

Discussion

634.	In a zero order reaction, reactants concentration does not change with time and the$?
A.	Time for half change is half the time taken for completion of the reaction
B.	Time for half change is independent of the initial concentration
C.	Time for completion of the reaction is independent of the initial concentration
D.	Reaction rate is trebled when the initial concentration is trebled
Answer» B. Time for half change is independent of the initial concentration

Discussion

635.	The rate of a chemical reaction is almost doubled for every 10¬¨‚àûC rise in temperature. The rate will increase __________ times, if the temperature rises form 10 to 100¬¨‚àûC.$?
A.	256
B.	512
C.	112
D.	612
Answer» C. 112

Discussion

636.	For an ideal mixed flow reactor (CSTR), the exit age distribution E(t) is given by$?
A.	A dirac delta function
B.	A step function
C.	A ramp function
D.	None of the above
Answer» E.

Discussion

637.	The conversion of a reactant, undergoing a first order reaction, at a time equal to three times the half life of the reaction is$?
A.	0.875
B.	0.5
C.	0.425
D.	Data insufficient to calculate
Answer» B. 0.5

Discussion

638.	The equilibrium constant of chemical reaction __________ in the presence of catalyst.$?
A.	Increases
B.	Decreases
C.	Remains unaffected
D.	Can either increase or decrease (depends on the type of catalyst)
Answer» D. Can either increase or decrease (depends on the type of catalyst)

Discussion

639.	At a given temperature, K‚Äö√á√Ö, K‚Äö√á√á and K3 are equilibrium constants for the following reactions 1, 2, 3 respectively.CH‚Äö√á√ë(g) + H‚Äö√á√áO(g) ‚Äö√°√£ CO(g) + 3H‚Äö√á√á(g), CO(g) + H‚Äö√á√áO(g) ‚Äö√°√£ CO‚Äö√á√á(g) + H‚Äö√á√á(g) CH‚Äö√á√ë(g) + 2H‚Äö√á√áO(g) ‚Äö√°√£ CO‚Äö√á√á(g) + 4H‚Äö√á√á(g) Then K‚Äö√á√Ö, K‚Äö√á√á and K3 are related as:$?
A.	K3 = K‚Äö√á√Ö.K‚Äö√á√á
B.	K3 = (K‚Äö√á√Ö.K‚Äö√á√á)0.5
C.	K3(K‚Äö√á√Ö+K‚Äö√á√á)/2
D.	K3 = (K‚Äö√á√Ö.K‚Äö√á√á)2
Answer» B. K3 = (K‚Äö√á√Ö.K‚Äö√á√á)0.5

Discussion

640.	Conversion increases with increase in temperature in case of a an __________ reaction.$?
A.	Autocatalytic
B.	Irreversible
C.	Reversible endothermic
D.	Reversible exothermic
Answer» D. Reversible exothermic

Discussion

641.	For a mixed flow reactor operating at steady state, the rate of reaction is given by$?
A.	FA0/V - dCsub>A/dt
B.	FA0/V + dCsub>A/dt
C.	FA0/V . Xsub>A
D.	- dCsub>A/dt
Answer» D. - dCsub>A/dt

Discussion

642.	The conversion for a first order liquid phase reaction. A ‚Äö√ú√≠ B in a CSTR is 50%. If another CSTR of the same volume is connected in series, then the % conversion at the exit of the second reactor will be$?
A.	60
B.	75
C.	90
D.	100
Answer» C. 90

Discussion

643.	If the time required for half change is inversely proportional to the square of initial concentration and the velocity depends on the units in which the concentration term is expressed, then the order of reaction is$?
A.	1
B.	2
C.	3
D.	0
Answer» D. 0

Discussion

644.	Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants ; but it is a function of reaction temperature. In a chemical reaction, the time required to reduce the concentration of reactant from 100 gm moles/litre to 50 gm moles/litre is same as that required to reduce it from 2 gm moles/litre to 1 gm mole/litre in the same volume. Then the order of this reaction is$?
A.	0
B.	1
C.	2
D.	3
Answer» C. 2

Discussion

645.	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

646.	The most suitable reactor for carrying out an auto-thermal reaction is a$?
A.	Batch reactor
B.	CSTR
C.	Semi-batch reactor
D.	Plug-flow reactor
Answer» C. Semi-batch reactor

Discussion

647.	Which of the following chemical reactions will be favoured by low pressure ?$?
A.	2HI ‚Äö√°√£ H‚Äö√á√á + I‚Äö√á√á
B.	N‚Äö√á√áO‚Äö√á√á ‚Äö√°√£ 2NO‚Äö√á√á
C.	N‚Äö√á√á + O‚Äö√á√á ‚Äö√°√£ 2NO
D.	None of these
Answer» C. N‚Äö√á√á + O‚Äö√á√á ‚Äö√°√£ 2NO

Discussion

648.	In an exothermic chemical reaction, the reactants compared to the products have$?
A.	Higher temperature
B.	More energy
C.	Less energy
D.	Same energy
Answer» C. Less energy

Discussion

649.	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

650.	If the time required to complete a definite fraction of reaction varies inversely as the concentration of the reactants, then the order of reaction is$?
A.	0
B.	1
C.	2
D.	3
Answer» D. 3

Discussion

Explore topic-wise MCQs in Chemical Engineering.

_Backmixing is most predominant in$?

_If the time required to change the concentration of reactant to half its original value is independent of the initial concentration, the order of reaction is$?

_Which of the following is not endothermic in nature?$?

_In autocatalytic reactions,$?

_The role of a catalyst in a chemical reaction is to change the$?

_Which of the following factors control the design of a fluid-solid reactor?$?

_In chamber process of sulphuric acid manufacture in industry, the gas phase oxidation of SO‚Äö√á√á to SO‚Äö√á√â is accomplished by a __________ reaction.$?

_Pick the WRONG design guideline for a reactor in which the reactions, A ‚Äö√ú√≠ R (desired) and A ‚Äö√ú√≠ S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k‚Äö√á√Ö/k‚Äö√á√á).Csub>Aa-b$?

_Chemical kinetics can predict the __________ of a chemical reaction.$?

_A backmix reactor$?

_The fractional volume change between no conversion and complete conversion, for the isothermal gas phase reaction, 2A ‚Äö√ú√≠ R, is$?

_Catalyst carriers$?

_A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction.$?

_The optimum performance for reactors operating in parallel is obtained when the feed stream is distributed in such a way, that the$?

_Consider the 'n' th order irreversible liquid phase reaction A ‚Äö√ú√≠ B. Which one of the following plots involving half life of the reaction (t1/2) and the initial reactant concentration (CA0) gives a straight line plot?$?

_Pick out the wrong statement pertaining to space velocity of flow reactors.$?

_The rate of reaction of a/an __________ reaction is not affected by temperature rise.$?

_The experimentally determined overall order of the reaction, A + B ‚Äö√ú√≠ C + D, is two. Then the$?

_A Catalyst$?

_Exposure of a photographic plate to produce a latent image is an example of __________ reaction.$?

_If in the gaseous phase reaction, N‚Äö√á√áO‚Äö√á√ë ‚Äö√°√£ 2NO‚Äö√á√á, x is the part of N‚Äö√á√áO‚Äö√á√ë which dissociates, then the number of molecules at equilibrium will be$?

_Given, 3H‚Äö√á√á + CO = CH‚Äö√á√ë + H‚Äö√á√áO, KP = 101.84 and, 4H‚Äö√á√á + CO‚Äö√á√á = CH‚Äö√á√ë + 2H‚Äö√á√áO, KP = 101.17the KP for the reaction CO + H‚Äö√á√áO = CO‚Äö√á√á + H‚Äö√á√á is$?

___________ catalytic reaction is involved in the thermal cracking of gas oil.$?

_The value of 'n' for a chemical reaction A ‚Äö√ú√≠ B, whose reaction rate is ‚Äö√ú√≠ CAn, will be __________ if the rate of the reaction increases by a factor of 8, when the concentration of is doubled.$?

_A second order reaction of the form A + B ‚Äö√ú√≠ C is called a pseudo-first order reaction, when$?

_Slurry reactors are characterised by the$?

_Space time equals the mean residence time$?

_Transition state theory relates the above quantities as$?

n' number of plug flow reactors (P.F.R) in series with a total volume 'V' gives the same conversion as one P.F.R. of volume$?

In an ideal mixed reactor (at steady state), the$?

The performance equations for constant density systems are identical for$?

Shift conversion reaction$?

In a zero order reaction, reactants concentration does not change with time and the$?

The rate of a chemical reaction is almost doubled for every 10¬¨‚àûC rise in temperature. The rate will increase __________ times, if the temperature rises form 10 to 100¬¨‚àûC.$?

For an ideal mixed flow reactor (CSTR), the exit age distribution E(t) is given by$?

The conversion of a reactant, undergoing a first order reaction, at a time equal to three times the half life of the reaction is$?

The equilibrium constant of chemical reaction __________ in the presence of catalyst.$?

Conversion increases with increase in temperature in case of a an __________ reaction.$?

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

The conversion for a first order liquid phase reaction. A ‚Äö√ú√≠ B in a CSTR is 50%. If another CSTR of the same volume is connected in series, then the % conversion at the exit of the second reactor will be$?

If the time required for half change is inversely proportional to the square of initial concentration and the velocity depends on the units in which the concentration term is expressed, then the order of reaction is$?

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

The most suitable reactor for carrying out an auto-thermal reaction is a$?

Which of the following chemical reactions will be favoured by low pressure ?$?

In an exothermic chemical reaction, the reactants compared to the products have$?

The heat of reaction$?

If the time required to complete a definite fraction of reaction varies inversely as the concentration of the reactants, then the order of reaction is$?