chemical engineering chemical reaction Mcqs
201. Threshold energy in a reaction is equal to the_________________?
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A. Neither A. nor B.

B. Activation energy

C. Normal energy of reactants

D. Sum of A. & B.
203. Integral method for analysing the kinetic data is used _____________________?
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A. When the data are scattered

B. For testing specific mechanisms with simple rate expressions

C. Both A. and B.

D. None of these

204. Which of the following is a characteristic of an ideal plug flow reactor ?
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A. Flat velocity profile

B. Axial dispersion

C. None of these

D. Uniform mixing

207. The rate of an autocatalytic reaction as shown in the bellow figure, is given by rA = k . CA . CB. In this case, the__________________?
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A. Plot of rA Vs CA is a straight line with slope k

B. Plot of rA Vs CA is a hyperbola

C. Rate of disappearance of reactant A is maximum, where CA = CB

D. Both B & C
209. A rise in temperature ______________________?
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A. Does not affect photo-chemical reaction rates

B. All A., B. and C.

C. Normally tends to increase the reaction rate

D. Does not affect a catalysed reaction

210. For a tubular reactor with space time ? and residence time ?, the following statement holds good ?
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A. ? and ? are always equal

B. ? = ?, for an isothermic tubular reactor in which the density of the process fluid is constant

C. ? = ?, for a non-isothermal reactor

D. ? = ?, when the fluid density changes in the reactor

212. Batch process is preferred over continuous process, when the___________________?
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A. Sales demand of product is not steady

B. idence time

C. All A., B. & C.

D. Same equipment cannot be used for several processes of the same nature

E. Product yields and quality cannot be achieved in continuous process, because of long

214. Space velocity____________________?
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A. Is a measure of the ease of the reaction

B. Is the maximum feed rate per unit volume of reactor for a given conversion

C. Describes the extensive operating characteristics of a tubular flow reactor

D. All A., B. and C.
217. Find a mechanism that is consistent with the rate equation and reaction given below ?
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A. A + A ? AA; AA + B ? A2B

B. A + A ? AA; AA + B ? A2B

C. A + B ? AB; AB + A ? A2B

D. A + B ? AB; AB + A ? A2B

E. #NAME?

223. The exit age distribution of fluid leaving a vessel is used to know the__________________?
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A. Extent of non-ideal flow in the vessel

B. None of these

C. Reaction mechanism

D. Activation energies of a reaction

224. In a continuous flow stirred tank reactor, the composition of the exit stream_________________?
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A. Depends upon the flow rate of inlet stream

B. Is same as that in the reactor

C. None of these

D. Is different than that in the reactor

225. For an ideal mixed flow reactor (CSTR), the exit age distribution E(t) is given by __________________?
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A. None of the above

B. A step function

C. A ramp function

D. A Dirac delta function

226. For the same residence time, which one will give the maximum conversion ?
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A. Single tubular flow reactor (v = 5 litres)

B. Stirred tank followed by tubular flow reactor (each of 2.5 litres)

C. Single stirred tank (v = 5 litres)

D. Two stirred tank (each of 2.5 litres) in series

227. For the reaction, A + B ? 2B + C,___________________?
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A. rA = -rB

B. rA = rB/2

C. rA = rB

D. rA = 2rB

229. The concentration of A in a first order reaction, A ? B, decreases_____________________?
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A. Very abruptly towards the end of the reaction

B. Linearly with time

C. Exponentially with time

D. Logarithmically with time

231. Which of the following is the most suitable for very high pressure gas phase reaction ?
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A. Tubular flow reactor

B. Fluidised bed reactor

C. Batch reactor

D. Stirred tank reactor

235. Semibatch reactor is preferred, when a/an__________________?
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A. A gas is to be reacted with liquid (e.g. hydrogenation of fat)

B. Undesirable side reaction (at high concentration of one of the reactants) is to be avoided

C. All A., B., and C.

D. A highly exothermic reaction is to be controlled

237. As the chemical reaction proceeds, the rate of reaction ___________________?
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A. Decreases

B. Increases

C. Remain same

D. May increase or decrease depending on the type of reaction

238. Equilibrium of a chemical reaction as viewed by kinetics is a ______________ state?
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A. None of these

B. Static steady

C. Dynamic steady

D. Dynamic unsteady

240. Shift conversion reaction_________________?
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A. Is non-catalytic

B. Converts CO to CO2 with steam

C. Converts N2 and H2 into NH3

D. Is highly exothermic

241. If the rate of a chemical reaction becomes slower at a given temperature, then the__________________?
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A. Initial concentration of the reactants remains constant

B. Free energy of activation is higher

C. Entropy changes

D. Free energy of activation is lower

242. The rate constant of a reaction is a function of the ___________________?
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A. Extent of reaction

B. Initial concentration of the reactants

C. Temperature of the system

D. Time of reaction

244. A catalyst promoter_________________?
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A. Acts as a catalyst support

B. Itself has very high activity

C. Improves the activity of a catalyst

D. All A., B. and C.

247. Rate of a chemical reaction is not affected by the____________________?
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A. Temperature

B. Catalyst

C. Number of molecules of reactants taking part in the reaction

D. Reactants concentration

249. A typical example of an exothermic reversible reaction conducted at high pressure in industry is____________________?
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A. Methanol synthesis

B. Dehydration of ethanol

C. Reformation of methane

D. Polymerisation of ethylene

250. Which of the following is a controlling factor in very fast heterogeneous reaction ?
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A. Pressure

B. Composition of reactant

C. Temperature

D. Heat and mass transfer effects