Pick out the wrong statement pertaining to space velocity of flow
reactors.
(A) The unit of space velocity is (time)
-1
(B) The space velocity of 3 hr
-1 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
-1 means that one third reactor volume of feed
at specified conditions are being fed into the reactor
(D) None of these

1 Answer

Answer :

(C) The space velocity of 3 hr
-1 means that one third reactor volume of feed
at specified conditions are being fed into the reactor

Related questions

Description : A space velocity of 5 hr -1 means that (A) Five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour (B) After every 5 hours, reactor is being filled with the feed ... be achieved in at least 5 hours (D) A fixed conversion of a given batch of feed takes 5 hours

Last Answer : (A) Five reactor volumes of feed (at specified conditions) are being fed into the reactor per hour

Description : A space time of 3 hours for a flow reactor means that (A) The time required to process one reactor volume of feed (measured at specified conditions) is 3 hours (B) Three reactor volumes of feed ... to dump the entire volume of the reactor with feed (D) Conversion is cent per cent after three hours

Last Answer : (A) The time required to process one reactor volume of feed (measured at specified conditions) is 3 hours

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 : 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 : Space velocity (A) Describes the extensive operating characteristics of a tubular flow reactor (B) Is the maximum feed rate per unit volume of reactor for a given conversion (C) Is a measure of the ease of the reaction (D) All (A), (B) and (C)

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

Description : Pick out the wrong statement pertaining to the roll crushers. (A) Maximum feed size determines the required roll diameter (B) For hard material's crushing, the reduction ratio should not ... ratio and differential roll speed affect production rate & energy consumed per unit of surface produced

Last Answer : (C) Both the rolls run necessarily at the same speed

Description : In flow reactors, the performance equations interrelate the rate of reaction to the (A) Feed rate (B) Reactor volume (C) Extent of reaction (D) All (A), (B) and (C)

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

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

Description : Pick out the wrong statement pertaining to fluid flow. (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5 (B) The Newtonian ... at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows

Last Answer : (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5

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 : 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 : 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 : A high space velocity means that a given (A) Reaction can be accomplished with small reactor (B) Conversion can be obtained with a high feed rate (C) Both (A) and (B) (D) None of these

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

Description : Pick out the wrong statement pertaining to the turbine agitator. (A) Recommended peripheral speed for the turbine agitator is 200-250 metres/minute (B) Pitched blade turbine agitator gives only radial flow with ... l/4th of agitator diameter (with central disc, it is l/8th of the agitator diameter)

Last Answer : (B) Pitched blade turbine agitator gives only radial flow with complete absence of the axial flow

Description : Select the wrong statement pertaining to flow of an incompressible fluid through a Venturimeter. (A) For frictionless flow, the fluid pressure entering the venturi meter will be exactly equal ... than an orificemeter (D) Venturimeter incurs less power loss compared to an equivalent orificemeter

Last Answer : (C) Venturimeter occupies less space than an orificemeter

Description : Pick out the correct statement pertaining to catalytic cracking. (A) With increase in the reactor pressure, octane number of gasoline decreases (B) With increase in the reactor temperature, gasoline yield decreases for a given ... with increase in the catalyst to oil ratio (D) All (A), (B) and (C)

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

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 : Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the ... ) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions

Last Answer : (C) The intercept of the Arrhenius plot is called the 'activation energy

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 : 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

Description : Pick out the correct statement pertaining to Venturimeter. (A) A Venturimeter with a fixed pressure drop discharges more, when the flow is vertically downward, than when the flow is vertically upward (B ... , when compressibility is taken into account, than when it is neglected (D) None of these

Last Answer : (D) None of these

Description : Pick out the wrong statement. (A) Higher specific gravity of petroleum products means higher C/H ratio (B) Aromatics have lower specific gravity than corresponding paraffins (C) Hydrocarbons of low ... of high specific gravity (e.g., aromatics) possess the maximum thermal energy per unit weight

Last Answer : (B) Aromatics have lower specific gravity than corresponding paraffins

Description : Pick out the wrong statement pertaining to leaching. (A) Fine solids cannot be leached in a Pachuca tank (B) Door classifier can be used for leaching of coarse solids (C) Vegetable seeds can be ... , Rotocel or Kennedy extractor (D) Very high temperature is not needed for the leaching of sugar beet

Last Answer : (A) Fine solids cannot be leached in a Pachuca tank

Description : Pick out the wrong statement pertaining to the cooling towers. (A) In case of induced draft cooling tower, the fan is placed at the top of the tower (B) Effectiveness of ... Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Last Answer : (D) Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb temperature

Description : Pick out the wrong statement pertaining to the analogy between equations of heat and mass transfer operations. (A) Sherwood number in mass transfer is analogous to Nusselt number in heat transfer ... heat transfer (D) Reynolds number remains the same in both heat and mass transfer

Last Answer : (C) Reynolds number in mass transfer is analogous to Grashoff number in heat transfer

Description : Pick out the wrong statement pertaining to solvent extraction of oil. Rate of extraction (A) Decreases with decrease of thickness of the flakes (B) Increases with the increasing flake size ... considerably with the rise of temperature (D) Decreases as the moisture content of flakes increases

Last Answer : (D) Decreases as the moisture content of flakes increases

Description : Pick out the wrong statement pertaining to nitric acid. (A) About 90% of nitric acid is manufactured by Ostwald's process (B) It is a strong mono basic acid which reacts with almost all the ... (mainly NO2 ) (D) Arc process of nitric acid manufacture is economical as compared to Ostwald's process

Last Answer : (D) Arc process of nitric acid manufacture is economical as compared to Ostwald's process

Description : Pick out the wrong statement pertaining to the properties of glasses. Glasses generally have (A) High electrical insulation properties (B) Sharp melting points (C) Low co-efficient of thermal expansion (D) Compressive strength much greater than their tensile strengths

Last Answer : (B) Sharp melting points

Description : Pick out the wrong statement pertaining to the soap manufacture. (A) Transparent soaps are made by cold process (B) Organic pigments are used as colouring materials in the soap manufacture (C) ... soaps are manufactured by hot process (D) Colourless rosin is used in the manufacture of laundry soaps

Last Answer : (A) Transparent soaps are made by cold process

Description : Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, PCl5 ⇌ PCl3 + Cl2.Degree of dissociation of PCl5 will (A) Decrease on addition of Cl2 (B) Increase on addition of ... at constant pressure (C) Decrease on increasing the pressure of the system (D) None of these

Last Answer : (D) None of thes

Description : Pick out the wrong statement. (A) 'Hold back' is defined as the fraction of material that stays longer than the mean residence time (B) Study of non-ideal flow reactor is done experimentally ... final stages of reaction (D) A batch reactor cannot be used to study the kinetics of catalytic reaction

Last Answer : (D) A batch reactor cannot be used to study the kinetics of catalytic reaction

Description : Pick out the correct statement pertaining to the flow through a converging-diverging tube. (A) The value of Mach number is always unity at the throat (B) No shock wave develops in the tube ... the converging portion of the tube, the density increases in the downstream direction (D) None of these

Last Answer : (B) No shock wave develops in the tube when the Mach number at exit is greater than unity

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 : 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 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 : 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 : Pick out the wrong statement. (A) In the McCabe-Thiele diagram for binary distillation, vertical feed line represents saturated liquid feed and horizontal feed line represents saturated vapour feed (B) In ... layers over a flat plate are of equal thickness, if Schmidt number is equal to unity

Last Answer : (C) For Laminar flow over a plate of length L, the local mass transfer co￾efficient at a distance L from the leading edge is 1.5 × 10 -2m/s. Then the average mass transfer co-efficient for the plate is 2 × 10 -2m/s

Description : 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 ... is different (C) Larger reactors have more space time compared to smaller ones (D) None of these

Last Answer : (A) Space time for each parallel line is same

Description : Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V' ratio (B) The extraction per unit ... and its cross￾section is wider at the bottom (D) Vander wall adsorption is also called chemisorption

Last Answer : (D) Vander wall adsorption is also called chemisorption

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 : 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)

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

Description : Pick out the wrong statement. (A) In process heat exchangers, saturated steam is preferred over the superheated steam (B) The maximum is the emissive power of a surface at a temperature T1 ... under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum

Last Answer : (B) The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength of λ1 . If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ1

Description : Pick up the incorrect statement from the following: (A) No deduction is made for the volume occupied by reinforcement (B) No deduction is made for the openings upto 0.1 sq.m (C) No deduction is made for volumes occupied by pipes, not exceeding 100 sq.cm in crosssection (D) None of these

Last Answer : (D) None of these

Description : Space time in flow reactor is (A) Usually equal to the residence time (B) The reciprocal of the space velocity (C) A measure of its capacity (D) Both (A) and (B)

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

Description : Pick out the wrong statement. (A) Heat transfer by radiation cannot occur across an absolute volume (B) In case of a shell and tube heat exchanger, the pressure drop through the shell is ... The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

Last Answer : (A) Heat transfer by radiation cannot occur across an absolute volume