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
Related Mcqs:
- 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 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 - 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. A catalyst does not alter the final position of equilibrium in a reversible reaction
B. A catalyst initiates a reaction
C. A catalyst is specific in reaction
D. A catalyst remains unchanged in chemical composition at the end the reaction - Pick out the wrong statement?
A. In a first order reaction, A → products; the reaction becomes slower as it proceeds, because
the concentration of A decreases and the rate is proportional to the concentration of A
B. Transition state theory approaches the problem of calculating reaction rates by concentrating
on the idea of activated complexes
C. According to the penetration theory, the mass transfer co-efficient decreases, if the exposure
time of an eddy to the solute decreases
D. If the rate of an irreversible reaction, A + B → 2C is k.CA.CB, then the reaction is always
elementary - 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 ?
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. Exit age description function E. and internal age distribution function (I) are related as, E = -(dI/dθ)
B. Chemisorption studies are useful in the determination of catalyst surface area and pore size distribution
C. A higher temperature favours the reaction of higher activation energy
D. A catalyst increases the potential energy barrier over which the reactants must pass to form products - 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. 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
