Recycling back of outlet stream to the reactor from an ideal CSTR
carrying out a first order liquid phase reaction will result in __________ in
conversion.
(A) Decrease
(B) Increase
(C) No change
(D) Either (A) or (B), depends on the type of reaction

1 Answer

Answer :

(C) No change

Related questions

Description : The conversion for a first order liquid phase reaction. A → B in a CSTRis 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

Last Answer : (B) 75

Description : An isothermal irreversible reaction is being carried out in an ideal tubular flow reactor. The conversion in this case will __________ with decrease in space time. (A) Increase (B) Increase exponentially (C) Decrease (D) Remain unchanged

Last Answer : (C) Decrease

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

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 : 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 : 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 : 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

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 : With the same reaction time, initial concentration and feed rate, the reaction 2A → B is carried out separately in CSTR and P.F. reactor of equal volumes. The conversion will be (A) Higher in P.F. reactor (B) Higher in CSTR (C) Same in both the reactors (D) Data insufficient; can't be predicted

Last Answer : (A) Higher in P.F. reactor

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 : The preferred reacting system for oxidation of o-xylene to phthalic anhydride is (A) Jacketed liquid phase CSTR (B) Jacketed steam heated multitubular reactor (C) Multitubular reactor with cooling (D) Multistage multitubular reactor with interstage cooling

Last Answer : (A) Jacketed liquid phase CSTR

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 XA and residence time data are collected for zero order liquid phase reaction in a stirred tank reactor. Which of the following will be a straight line? (A) XA Vs . τ (B) XA Vs ln τ (C) XA /(1 - XA )Vs τ (D) XA (1 - XA )Vs τ

Last Answer : (A) XA Vs . τ

Description : Pick out the wrong statement. (A) The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction (B) With ... phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction

Last Answer : (B) With increase in temperature, the equilibrium constant increases for an exothermic reaction

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 : For reactions in parallel viz A → P (desired product) and A → Q (unwanted product), if the order of the desired reaction is higher than that of the undesired reaction, a (A) Batch reactor is preferred over a ... a single CSTR for high yield (C) Both (A) and (B) (D) Single CSTR is the most suitable

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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

Description : The use of space time is preferred over the mean residence time in the design of a/an (A) Batch reactor (B) Ideal tubular-flow reactor (C) Slurry reactor (D) CSTR

Last Answer : (B) Ideal tubular-flow 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 : The equilibrium constant of chemical reaction __________ in the presence of catalyst. (A) Increases (B) Decreases (C) Remain unaffected (D) Can either increase or decrease (depends on the type of catalyst)

Last Answer : (C) Remain unaffected

Description : A first order reaction requires two equal sized CSTR. The conversion is (A) Less when they are connected in series (B) More when they are connected in series (C) More when they are connected in parallel (D) Same whether they are connected in series or in parallel

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Description : With increases in pressure, the conversion of Ammonium carbamate into urea (A) Increases (B) Decreases (C) Remains unaltered (D) Can either increase or decrease depends on biuret content

Last Answer : (A) Increases

Description : With increase in the space time of an irreversible isothermal reaction being carried out in a P.F. reactor, the conversion will (A) Increase (B) Decrease (C) Remain same (D) Data in insufficient; can't be predicted

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Description : In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on other factors

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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

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Description : 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 ... preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

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Description : The 'E' curve for a non-ideal reactor defines the fraction of fluid having age between t and t + dt (A) At the inlet (B) At the outlet (C) In the reactor (D) Averaged over the inlet and outlet

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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

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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

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Description : For nearly isothermal operation involving large reaction time in a liquid-phase reaction, the most suitable reactor is a __________ reactor. (A) Stirred tank (B) Tubular flow (C) Batch (D) Fixed bed

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Description : A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted ... ) Remain unaffected (D) May increase or decrease; depends on the thickness of each layer

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Description : Thermal conductivities of most of the liquids __________ with rise in temperature. (A) Increases (B) Decreases (C) Remains unchanged (D) May increase or decrease; depends on the liquid

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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

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Description : For an autocatalytic reactor, the suitable reactor set up is (A) P.F. reactors in series (B) CSTR in series (C) CSTR followed by P.F. reactor (D) P.F. reactor followed by CSTR

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Description : In a continuous flow stirred tank reactor, the composition of the exit stream (A) Is same as that in the reactor (B) Is different than that in the reactor (C) Depends upon the flow rate of inlet stream (D) None of these

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Description : The main purpose of recycling the byproduct hydrogen gas in the reformer reactor is to (A) Obviate catalyst poisoning (B) Maintain the reaction temperature (C) Sustain the reactor pressure (D) Hydrogenate the feed stock

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Description : Pick out the correct statement. (A) Like internal energy and enthalpy, the absolute value of standard entropy for elementary substances is zero (B) Melting of ice involves increase in enthalpy and ... of an ideal gas depends only on its pressure (D) Maximum work is done under reversible conditions

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Description : In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3 ), the value of the equilibrium constant depends on the (A) Total pressure of the system (B) Volume of the reactor (C) Temperature (D) Initial concentration of N2 and H2

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Description : Conversion of dynamic velocity head into static pressure head in a centrifugal pump is the result of : (a) Increasing area of flow between adjacent vanes from inlet to outlet (b) Difference in pressure between suction and delivery ends (c) Radial thrust in pumps (d) Stuffing Box

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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

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Description : A catalyst in a chemical reaction __________ free energy change in the reaction. (A) Increases (B) Decreases (C) Either (A) or (B); depends on the type of catalyst (D) Neither (A) nor (B)

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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

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