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

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
by

1 Answer

Answer :

(C) Presence of lateral mixing
by

Related questions

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

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 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

In an ideal P.F.R. at steady state conditions (A) The composition of reactants remains constant along a flow path (B) The conversion of the reactant varies from point to point along a flow path (C) There is no lateral mixing of fluid (D) There may be diffusion along the flow path

Description : In an ideal P.F.R. at steady state conditions (A) The composition of reactants remains constant along a flow path (B) The conversion of the reactant varies from point to point along a flow path (C) There is no lateral mixing of fluid (D) There may be diffusion along the flow path

Last Answer : (B) The conversion of the reactant varies from point to point along a flow path

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

. A batch reactor is characterised by (A) Constant residence time(B) Variation in extent of reaction and properties of the reaction mixture withtime(C) Variation in reactor volume(D) Very low conversion

Description : . A batch reactor is characterised by (A) Constant residence time (B) Variation in extent of reaction and properties of the reaction mixture with time (C) Variation in reactor volume (D) Very low conversion

Last Answer : (B) Variation in extent of reaction and properties of the reaction mixture with time

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

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

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) 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

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 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

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

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

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

Paddle agitator (A) Is suitable for mixing low viscosity liquids (B) Produces axial flow (C) Moves at very high speed (D) None of these

Description : Paddle agitator (A) Is suitable for mixing low viscosity liquids (B) Produces axial flow (C) Moves at very high speed (D) None of these

Last Answer : (A) Is suitable for mixing low viscosity liquids

A propeller agitator (A) Produces mainly axial flow (B) Is used for mixing high viscosity pastes (C) Runs at very slow speed (2 rpm) (D) All (A), (B) and (C)

Description : A propeller agitator (A) Produces mainly axial flow (B) Is used for mixing high viscosity pastes (C) Runs at very slow speed (2 rpm) (D) All (A), (B) and (C)

Last Answer : (A) Produces mainly axial flow

Propellers are (A) Axial flow mixers (B) Low speed impeller (C) Used for mixing liquids of high viscosity (D) Radial flow mixers

Description : Propellers are (A) Axial flow mixers (B) Low speed impeller (C) Used for mixing liquids of high viscosity (D) Radial flow mixers

Last Answer : (A) Axial flow mixers

Mean residence time is equal to the space time, when (A) The feed rate is measured at temperature and pressure in the reactor (B) The temperature, pressure and the density of reaction mixture remains constant throughout the reactor (C) There is no change in number of moles in gaseous reaction (D) All (A), (B) and (C)

Description : Mean residence time is equal to the space time, when (A) The feed rate is measured at temperature and pressure in the reactor (B) The temperature, pressure and the density of reaction mixture remains constant throughout ... no change in number of moles in gaseous reaction (D) All (A), (B) and (C)

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

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

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)

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

Description : 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

Last Answer : (C) Smaller than

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

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

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

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

A batch adiabatic reactor at an initial temperature of 373°K is being used for the reaction, A → B. Assume the heat of reaction is - 1kJ/mole at 373°K and heat capacity of both A and B to be constant and equal to 50J/mole.K. The temperature rise after a conversion of 0.5 will be: (A) 5°C (B) 10°C (C) 20°C (D) 100°C

Description : A batch adiabatic reactor at an initial temperature of 373°K is being used for the reaction, A → B. Assume the heat of reaction is - 1kJ/mole at 373°K and heat capacity of both A and B to be constant and equal ... rise after a conversion of 0.5 will be: (A) 5°C (B) 10°C (C) 20°C (D) 100°C

Last Answer : (B) 10°C

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

In case of a P.F.R., there (A) May be lateral mixing of fluid (B) Should not be any mixing along the flow path (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : In case of a P.F.R., there (A) May be lateral mixing of fluid (B) Should not be any mixing along the flow path (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, one reactant is charged batch wise, while the other reactant is fed continuously (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system (D) In a continuous flow reactor, both the reactants and the products flow out continuously

Description : Pick out the wrong statement. (A) In a batch reactor, which is exclusively used for liquid phase reactions; temperature pressure and composition may vary with time (B) In a semi-batch reactor, ... system (D) In a continuous flow reactor, both the reactants and the products flow out continuously

Last Answer : (C) In a continuous flow reactor, uniform concentration cannot be maintained throughout the vessel even in a well agitated system

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

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

Description : 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

Last Answer : (A) When the density of the reaction mixture is constant

In an ideal tubular-flow reactor (A) There is no mixing in longitudinal direction (B) Mixing takes place in radial direction (C) There is a uniform velocity across the radius (D) All (A), (B) and (C)

Description : In an ideal tubular-flow reactor (A) There is no mixing in longitudinal direction (B) Mixing takes place in radial direction (C) There is a uniform velocity across the radius (D) All (A), (B) and (C)

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

Fluidised bed reactor is characterised by (A) Uniformity of temperature (B) Comparatively smaller equipment (C) Very small pressure drop (D) Absence of continuous catalyst regeneration facility

Description : Fluidised bed reactor is characterised by (A) Uniformity of temperature (B) Comparatively smaller equipment (C) Very small pressure drop (D) Absence of continuous catalyst regeneration facility

Last Answer : (A) Uniformity of temperature

Pick out the wrong statement. (A) Constant pressure distillation cannot separate an Azeotropic mixture (B) Relative volatility of a binary mixture changes appreciably with the minor change in temperature (C) The relative volatility of a binary mixture at Azeotropic composition is unity (D) Flash distillation is practised on wide spread scale in petroleum refinery

Description : Pick out the wrong statement. (A) Constant pressure distillation cannot separate an Azeotropic mixture (B) Relative volatility of a binary mixture changes appreciably with the minor change in ... unity (D) Flash distillation is practised on wide spread scale in petroleum refinery

Last Answer : (B) Relative volatility of a binary mixture changes appreciably with the minor change in temperature

Which of the following fixes the volume of a batch reactor for a particular conversion and production rate? (A) Operating conditions (e.g. pressure and temperature) (B) Rate constant (C) Density of mixture (D) None of these

Description : Which of the following fixes the volume of a batch reactor for a particular conversion and production rate? (A) Operating conditions (e.g. pressure and temperature) (B) Rate constant (C) Density of mixture (D) None of these

Last Answer : (C) Density of mixture

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

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

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

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

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

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

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

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

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

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

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