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 same composition as fluid
within the reactor and the space time is equivalent to holding time for constant density system
C. Plug flow reactor (PFR) is always smaller than mixed reactor for all positive reaction orders
for a particular duty
D. Reaction rate does not decrease appreciably as the reaction proceeds in case of an
autocatalytic reaction
Related Mcqs:
- Pick out the wrong statement ?
A. For the same conversion, the holding time required in a batch reactor, is always equal to the space time required in a PFR
B. Two mixed reactors of unequal size are available for producing a specified product, formed by
a homogenous second order reaction. To achieve maximum production rate, the smaller
reactor should be placed in series before the larger reactor
C. Arrhenius equation describing the effect of temperature on rate constant is given by,
K = A.e-Ea/RT
D. The mechanism for the decomposition of CH3CHO into CH4 and CO in presence of I2 is:
CH3CHO + I2 → CH3I + HI + CO; slow
CH3I + HI → CH4 + I2; fast
Then the rate of disappearance of CH3CHO is equal to K.CCH3I.CHI and acts as a catalyst - Pick out the wrong statement ?
A. Visible radiation provides the necessary activation energy in photochemical reactions
B. The order and molecularity of a complex reaction may not be the same
C. For a second order reaction, the slope of the graph/plot between rate and (concentration) is
equal to the rate constant (k)
D. Molecularity of the reaction is always a whole number greater than zero - 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 by stimulus-response technique
C. For studying a chemical reaction, it is desirable to monitor the reactants during initial stages
and the products during the final stages of reaction
D. A batch reactor cannot be used to study the kinetics of catalytic reaction - 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 - 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 - 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 reaction is practically
irreversible in nature
C. The intercept of the Arrhenius plot is called the ‘activation energy’
D. Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant
regions - Pick out the wrong statement ?
A. In a multistep reaction, the slowest step is the rate determining step
B. In general, the rate of a reaction becomes triple for every 10°C rise in temperature
C. Slow chemical reactions have generally high values of activation energy
D. Molecularity of a reaction cannot be zero but the order of a reaction can be zero - 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 - 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 - 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
