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
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. Autocatalytic reactions are exemplified by microbial fermentation reactions
B. The slowest step has the greatest influence on the overall reaction rate in case of an
irreversible series reaction
C. The fractional conversion at any time is same for both the constant as well as the variable
volume system in case of an irreversible unimolecular type first order reaction
D. Hydrolysis of ester in presence of alkali or acid is a zero order reaction - 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. Catalytic activity of enzyme catalysed reactions which is affected by temperature, pH value &
chemical agents, is maximum at a temperature of about 45°C
B. Most of the enzyme catalysed reactions involve at least two substrates
C. Enzymes help in increasing the activation energy of the reaction
D. Equilibrium concentrations in enzyme catalysed reactions can be calculated by using the
thermodynamic properties of substrates & products - Pick out the wrong statement?
A. Use of different catalysts in a reversible catalytic chemical reaction does not change the
equilibrium composition
B. Alumina is added as a promoter to iron catalyst in ammonia synthesis reaction
C. Activation energy for a reaction is obtained from the intercept of the Arrhenius plot
D. Presence of inerts affects the equilibrium conversion of - 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. 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
