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

1 Answer

Answer :

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

Related questions

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

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

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

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

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

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

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

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

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

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

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)

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

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

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

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

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

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

Description : . A first order irreversible reaction, A → B is carried out separately in a constant volume as well as in a variable volume reactor for a particular period. It signifies that __________ in the two ... be different (C) Both the conversion as well as concentrations will be different (D) None of these

Last Answer : (B) Conversion in both will be the same but concentrations will be different

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

Description : 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

Last Answer : (A) Equal in size

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

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

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

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

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

Description : Which of the following factors control the design of a fluid-solid reactor? (A) Reaction kinetics for single particle (B) Size distribution of solids being treated (C) Flow patterns of solids and fluid in the reactor (D) All (A), (B) and (C)

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

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

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

Description : The space time is equivalent to the holding time in a steady state mixed reactor for (A) Non-isothermal gas reaction (B) Variable fluid density systems (C) Constant fluid density systems (D) Gas reactions with changing number of moles

Last Answer : (C) Constant fluid density systems

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

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

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

Description : With increase in K2 /K1 in case of a unimolecular type elementary reactions as shown in the bellow figure, the fractional yield of 'R' in mixed reactor (for a given conversion of 'A'). (A) Decreases (B) Increases (C) Increases linearly (D) Remain same

Last Answer : (A) Decreases

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

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

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

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

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

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

Last Answer : (A) 0

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

Last Answer : (A) 0

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

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

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

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

Last Answer : (A) Slurry

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

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