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

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
by

1 Answer

Answer :

(C) Smaller than
by

Related questions

Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal mixed reactor at steady state, the exit stream has the samecomposition as fluid within the reactor and the space time is equivalent toholding time for constant density system(C) Plug flow reactor (PFR) is always smaller than mixed reactor for allpositive reaction orders for a particular duty(D) Reaction rate does not decrease appreciably as the reaction proceeds incase of an autocatalytic reaction

Description : Pick out the wrong statement. (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity(B) For an ideal ... D) Reaction rate does not decrease appreciably as the reaction proceeds in case of an autocatalytic reaction

Last Answer : (A) For a first order consecutive reaction, a tubular flow reactor as compared to a stirred tank reactor provides higher overall selectivity

Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a measure of its capacity and is equal to the residence time when the density of reaction mixture is constant (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty (D) In an ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Description : Pick out the wrong statement. (A) The vessel dispersion number (D/UL) for plug flow and mixed flow approaches zero and infinity respectively (B) Space time in a flow reactor is a ... ideal tubular flow reactor, mixing takes place in radial direction and there is no mixing in longitudinal direction

Last Answer : (C) Mixed reactor is always smaller than the plug flow reactor for all positive reaction orders for a particular duty

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

Description : 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 ... (C) Reactor size is independent of the type of flow (D) Density variation during reaction affects design

Last Answer : (A) Mixed reactor is always larger than the plug-flow reactor

Pick out the wrong statement. (A) The integral method of analysing kinetic data is used when the data is scattered (B) The differential method of analysing kinetic data requires more accurate or larger amounts of data (C) When the reaction rate is independent of temperature, the reaction is said to be of zero order (D) The ratio of volumes of plug flow reactor to that of mixed reactor is always less than one for identical feed composition, flow rate, conversion and for all positive reaction orders

Description : Pick out the wrong statement. (A) The integral method of analysing kinetic data is used when the data is scattered (B) The differential method of analysing kinetic data requires more accurate ... less than one for identical feed composition, flow rate, conversion and for all positive reaction orders

Last Answer : (C) When the reaction rate is independent of temperature, the reaction is said to be of zero order

With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly

Description : With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion). (A) Increases (B) Decreases (C) Remain same (D) Increases linearly

Last Answer : (A) Increases

The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m3 is fed to the reactor at the rate of 0.01 m3 /s and at a temperature of 500 K. If the exit conversion is 20%, then the exit temperature (in k) is (Data: Heat of reaction at 298 K = - 50000 kJ/ kmole of A reacted Heat capacities CPA = CPB = 100kJ/kmole. K (may be assumed to be independent of temperature)) (A) 400 (B) 500 (C) 600 (D) 1000

Description : The reaction A → B is conducted in an adiabatic plug flow reactor (PFR). Pure A at a concentration of 2 kmol/m3 is fed to the reactor at the rate of 0.01 m3 /s and at a temperature of 500 K. If the exit ... /kmole. K (may be assumed to be independent of temperature)) (A) 400 (B) 500 (C) 600 (D) 1000

Last Answer : (C) 600

The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is (A) Backmix reactor (B) Plug flow reactor (C) Series of CSTR (D) PFR in series

Description : The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is (A) Backmix reactor (B) Plug flow reactor (C) Series of CSTR (D) PFR in series

Last Answer : A) Backmix reactor

A back mix reactor is (A) Suitable for gas phase reactions (B) Ideal at very low conversion (C) Same as plug flow reactor (PFR) (D) Same as ideal stirred tank reactor

Description : A back mix reactor is (A) Suitable for gas phase reactions (B) Ideal at very low conversion (C) Same as plug flow reactor (PFR) (D) Same as ideal stirred tank reactor

Last Answer : (D) Same as ideal stirred tank reactor

Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same (D) Half life of a reaction increases with increased initial concentration for reaction orders more than one

Description : Pick out the wrong statement: (A) Chemical reactions with high activation energy are very temperature sensitive (B) A flat velocity profile exists in a plug flow reactor (C) The residence ... D) Half life of a reaction increases with increased initial concentration for reaction orders more than one

Last Answer : (C) The residence time for all the elements of fluid in case of a P.F.R. need not be same

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)

Description : 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)

Last Answer : (D) Either (A), (B) and (C)

Kinetics of a solid catalysed reaction can best be studied in a __________ reactor. (A) Batch (B) Plug-flow (C) Mixed (D) None of these

Description : Kinetics of a solid catalysed reaction can best be studied in a __________ reactor. (A) Batch (B) Plug-flow (C) Mixed (D) None of these

Last Answer : (C) Mixed

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

Description : 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

Last Answer : (B) PFR of volume V

For series reaction, the relative yield (A) Is always greater for plug-flow reactor than for the single CSTR of the same volume (B) Statement in (A) is wrong (C) Decreases with increasing conversion (D) Both (A) and (C) hold good

Description : For series reaction, the relative yield (A) Is always greater for plug-flow reactor than for the single CSTR of the same volume (B) Statement in (A) is wrong (C) Decreases with increasing conversion (D) Both (A) and (C) hold good

Last Answer : (D) Both (A) and (C) hold good

The pressure outside a bubble/droplet of liquid is __________ the internal pressure. (A) Greater than (B) Less than (C) Equal to (D) Unpredictable; depends on the bubble size

Description : The pressure outside a bubble/droplet of liquid is __________ the internal pressure. (A) Greater than (B) Less than (C) Equal to (D) Unpredictable; depends on the bubble size

Last Answer : Option B

An irreversible first order reaction is being carried out in a CSTR and PFR of same volume. The liquid flow rates are same. The relative conversion will (A) Be more in CSTR than in PFR (B) Be more in PFR than in CSTR (C) Be same in both cases (D) Depend on the temperature

Description : An irreversible first order reaction is being carried out in a CSTR and PFR of same volume. The liquid flow rates are same. The relative conversion will (A) Be more in CSTR than in PFR (B) Be more in PFR than in CSTR (C) Be same in both cases (D) Depend on the temperature

Last Answer : (B) Be more in PFR than in CSTR

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

Description : 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

Last Answer : (A) 0.5

An isothermal aqueous phase reversible reaction, P ⇌ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m3 .h is given by, r = 0.5CP - 0.125CR. A stream containing only P enters the reactor. The residence time required (in hours) for 40% conversion of P is (A) 0.80 (B) 1.33 (C) 1.60 (D) 2.67

Description : An isothermal aqueous phase reversible reaction, P ⇌ R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m3 .h is given by, r = 0.5CP - 0.125CR. A stream containing only P enters the reactor. The ... (in hours) for 40% conversion of P is (A) 0.80 (B) 1.33 (C) 1.60 (D) 2.67

Last Answer : (C) 1.60

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

Description : 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

Last Answer : (A) Maximum at the inlet of the reactor

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

Description : 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

Last Answer : (B) Is same as ideal stirred tank reactor

A reversible liquid phase endothermic reaction is to be carried out in a plug flow reactor. For minimum reactor volume, it should be operated such that the temperature along the length (A) Decreases (B) Increases (C) Is at the highest allowable temperature throughout (D) First increases and then decreases

Description : A reversible liquid phase endothermic reaction is to be carried out in a plug flow reactor. For minimum reactor volume, it should be operated such that the temperature along the length (A) ... Increases (C) Is at the highest allowable temperature throughout (D) First increases and then decreases

Last Answer : (C) Is at the highest allowable temperature throughout

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

Description : 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 ... through a minimum along the length of the reactor (D) Is maximum at the exit of the reactor

Last Answer : (A) Is maximum at the inlet of the reactor

In a semi-batch reactor, (A) Mixing takes place in axial direction only (B) Velocity of reaction can be controlled (C) Condition similar to plug flow reactor exists (D) Residence time is constant

Description : In a semi-batch reactor, (A) Mixing takes place in axial direction only (B) Velocity of reaction can be controlled (C) Condition similar to plug flow reactor exists (D) Residence time is constant

Last Answer : (B) Velocity of reaction can be controlled

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

Description : 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

Last Answer : (C) Presence of lateral mixing

The gas phase reaction 2A ⇌ B is carried out in an isothermal plug flow reactor. The feed consists of 80 mole % A and 20 mole % inerts. If the conversion of A at the reactor exit is 50%, then CA/CA0 at the outlet of the reactor is (A) 2/3 (B) 5/8 (C) 1/3 (D) 3/8

Description : The gas phase reaction 2A ⇌ B is carried out in an isothermal plug flow reactor. The feed consists of 80 mole % A and 20 mole % inerts. If the conversion of A at the reactor exit is 50%, then CA/CA0 at the outlet of the reactor is (A) 2/3 (B) 5/8 (C) 1/3 (D) 3/8

Last Answer : (B) 5/8

Which of the following is the optimum operating condition for an exothermic reversible reaction taking place in a plug-flow reactor? (A) Temperature should be high in the beginning and decreased towards the end of the reaction (B) Very low temperature should be used throughout the reaction (C) Very high temperature should be used throughout the reaction (D) None of these

Description : Which of the following is the optimum operating condition for an exothermic reversible reaction taking place in a plug-flow reactor? (A) Temperature should be high in the beginning and decreased towards ... reaction (C) Very high temperature should be used throughout the reaction (D) None of these

Last Answer : (A) Temperature should be high in the beginning and decreased towards the end of the reaction

For a fluidised bed reactor, the most suitable/relevant model is a __________ model. (A) Tank in series (B) Bubbling bed (C) Plug flow (D) None of these

Description : For a fluidised bed reactor, the most suitable/relevant model is a __________ model. (A) Tank in series (B) Bubbling bed (C) Plug flow (D) None of these

Last Answer : (B) Bubbling bed

N' plug flow reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for __________ order reactions. (A) First (B) Second (C) Third (D) Any

Description : N' plug flow reactors in series with a total volume 'V' gives the same conversion as a single plug flow reactor of volume 'V' for __________ order reactions. (A) First (B) Second (C) Third (D) Any

Last Answer : (D) Any

Vegetable oils are hydrogenated in a __________ reactor. (A) Slurry (B) Plug flow (C) Homogeneous catalytic (D) None of these

Description : Vegetable oils are hydrogenated in a __________ reactor. (A) Slurry (B) Plug flow (C) Homogeneous catalytic (D) None of these

Last Answer : (A) Slurry

Hydrogenation of oil takes place in a/an __________ reactor. (A) Autothermal (B) Trickle bed (C) Plug flow (D) None of these

Description : Hydrogenation of oil takes place in a/an __________ reactor. (A) Autothermal (B) Trickle bed (C) Plug flow (D) None of these

Last Answer : (B) Trickle bed

An exothermic reaction takes place in an adiabatic reactor. The product temperature __________ reactor feed temperature. (A) Is always equal to (B) Is always greater than (C) Is always less than (D) May be greater or less than

Description : An exothermic reaction takes place in an adiabatic reactor. The product temperature __________ reactor feed temperature. (A) Is always equal to (B) Is always greater than (C) Is always less than (D) May be greater or less than

Last Answer : (B) Is always greater than

The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is always > 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (A) Plug

The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : The ratio of Murphree plate efficiency to point efficiency is 1 in a __________ flow model. (A) Plug (B) Perfectly mixed (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Perfectly mixed

Fluid flow in a real packed bed can be approximated as __________ model. (A) Plug flow (B) Dispersion (C) Mixed flow (D) Tank in series

Description : Fluid flow in a real packed bed can be approximated as __________ model. (A) Plug flow (B) Dispersion (C) Mixed flow (D) Tank in series

Last Answer : (B) Dispersion

The ratio of volume of mixed reactor to the volume of P.F.R. (for identical flow rate, feed composition and conversion) for zero order reaction is: (A) ∞(B) 0 (C) 1 (D) > 1

Description : The ratio of volume of mixed reactor to the volume of P.F.R. (for identical flow rate, feed composition and conversion) for zero order reaction is: (A) ∞ (B) 0 (C) 1 (D) > 1

Last Answer : (C) 1

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) d(VCA )/dt = -F (CAF - CA ) - kCA 2V (B) d(VCA )/dt = F (CAF - CA ) - kCA 2V (C) d(VCA )/dt = -FCA - kCA 2V (D) d(VCA )/dt = FCAF - kCA 2V

Description : 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 ... 2V (C) d(VCA )/dt = -FCA - kCA 2V (D) d(VCA )/dt = FCAF - kCA 2V

Last Answer : (D) d(VCA )/dt = FCAF - kCA 2V

A first order reaction requires two unequal sized CSTR. Which of thefollowing gives higher yield?(A) Large reactor followed by smaller one(B) Smaller reactor followed by larger one(C) Either of the arrangement (A) or (B) will give the same yield(D) Data insufficient, can't be predicted

Description : A first order reaction requires two unequal sized CSTR. Which of thefollowing gives higher yield? (A) Large reactor followed by smaller one (B) Smaller reactor followed by larger one (C) Either of the arrangement (A) or (B) will give the same yield (D) Data insufficient, can't be predicted

Last Answer : (C) Either of the arrangement (A) or (B) will give the same yield

Fractional conversion __________ with increase in pressure for ammonia synthesis reaction i.e., N2 + 3H2 ⇌ 2NH3 . (A) Increases (B) Decreases (C) Remains unchanged (D) Unpredictable from the data

Description : Fractional conversion __________ with increase in pressure for ammonia synthesis reaction i.e., N2 + 3H2 ⇌ 2NH3 . (A) Increases (B) Decreases (C) Remains unchanged (D) Unpredictable from the data

Last Answer : (A) Increases

Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. (A) Increases (B) Remains unchanged (C) Decreases (D) Unpredictable from the data

Description : Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. (A) Increases (B) Remains unchanged (C) Decreases (D) Unpredictable from the data

Last Answer : (C) Decreases

The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Description : The equilibrium constant of a catalytic chemical reaction __________ due to the presence of a catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Last Answer : (C) Remain unaffected

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

Description : 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

Last Answer : (D) None of the above

Which of the following is the most suitable for isothermal operation? (A) Batch reactor (B) Back-mix reactor (C) Plug-flow reactor (D) Fixed bed reactor

Description : Which of the following is the most suitable for isothermal operation? (A) Batch reactor (B) Back-mix reactor (C) Plug-flow reactor (D) Fixed bed reactor

Last Answer : (B) Back-mix reactor

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

Description : 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

Last Answer : (D) CSTR followed by a plug flow reactor

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

Description : 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

Last Answer : (C) A single CSTR

For an ideal plug flow reactor, the value of Peclet number is (A) 0 (B) 1 (C) 10 (D) ∞

Description : For an ideal plug flow reactor, the value of Peclet number is (A) 0 (B) 1 (C) 10 (D) ∞

Last Answer : (A) 0

What is the dispersion number for a plug flow reactor? (A) 0 (B) ∞ (C) 1 (D) -1

Description : What is the dispersion number for a plug flow reactor? (A) 0 (B) ∞ (C) 1 (D) -1

Last Answer : (A) 0

Which of the following will give maximum gas conversion? (A) Fixed bed reactor (B) Fluidised bed reactor (C) Semi-fluidised bed reactor (D) Plug-flow catalytic reactor

Description : Which of the following will give maximum gas conversion? (A) Fixed bed reactor (B) Fluidised bed reactor (C) Semi-fluidised bed reactor (D) Plug-flow catalytic reactor

Last Answer : (C) Semi-fluidised bed reactor

For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of: (A) Ideal plug flow (B) Bypass (C) Dead zone (D) Channelling

Description : For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of: (A) Ideal plug flow (B) Bypass (C) Dead zone (D) Channelling

Last Answer : (C) Dead zone

Autocatalytic reactions are best carried out in a (A) CSTR (B) CSTR in series (C) Plug flow reactor (D) Recycle reactor

Description : Autocatalytic reactions are best carried out in a (A) CSTR (B) CSTR in series (C) Plug flow reactor (D) Recycle reactor

Last Answer : (D) Recycle reactor

For the liquid phase zero order irreversible reaction A → B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1min -1 . What will be the conversion for a PFR with a space velocity of 0.2 min -1? Assume that all the other operating conditions are the same for CSTR and PFR. (A) 0.15(B) 0.30 (C) 0.60 (D) 0.90

Description : For the liquid phase zero order irreversible reaction A → B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1min -1 . What will be the conversion for a PFR with a space velocity of 0.2 min ... conditions are the same for CSTR and PFR. (A) 0.15 (B) 0.30 (C) 0.60 (D) 0.90

Last Answer : (C) 0.60