chemical engineering Mcqs
3051. Octane number of n-heptane is assumed to be_________________?
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A. ?

B. 0

C. 70

D. 100

3052. Chemical reaction rate of a component depends upon the______________________?
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A. Temperature of the system

B. Pressure of the system

C. All A., B. and C.

D. Composition of the component only

3053. In the gaseous phase ammonia formation reaction (N2 + 3H2 ? 2NH3), the value of the equilibrium constant depends on the_________________?
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A. Total pressure of the system

B. Temperature

C. Initial concentration of N2 and H2

D. Volume of the reactor

3054. With increase in initial concentration, the fractional conversion of a first order reaction in a given time___________________?
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A. Decreases

B. Increases

C. Remain constant

D. Unpredictable

3055. Hydrocracking employs ___________________?
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A. High temperature and low pressure

B. High pressure & temperature

C. High pressure and low temperature

D. Low pressure & temperature

3056. An imbalanced chemical reaction equation is against the law of________________?
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A. Constant proportion

B. Multiple proportion

C. None of these

D. Conservation of mass
3057. From collision theory, the reaction rate constant is proportional to_________________?
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A. Tm exp (-E/RT)

B. ?T

C. exp (-E/2RT)

D. exp (-E/RT)

3058. In a reaction, the threshold energy is equal to (where, A = activation energy N = normal energy of reactants) ?
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A. A + N

B. A N

C. A

D. N

3059. The rate constant of a first order reaction depends on the ________________?
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A. Temperature

B. Concentration of the product

C. Time

D. Concentration of the reactant

3060. Design of heterogamous catalytic reactor involves consideration of _______________ steps?
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A. Only chemical

B. Only physical

C. Both A. & B.

D. Neither A. nor B.

3061. If the time required to complete a definite fraction of reaction varies inversely as the concentration of the reactants, then the order of reaction is________________?
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A. 4

B. 3

C. 2

D. 1

3062. In flow reactors, the performance equations interrelate the rate of reaction to the___________________?
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A. Reactor volume

B. Extent of reaction

C. Feed rate

D. All A., B. and C.
3063. When an exothermic reversible reaction is conducted adiabatically, the rate of reaction____________________?
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A. Continuously decreases

B. Continuously increases

C. Passes through a maximum

D. Passes through a minimum

3064. The best method of determining sulphur in crude oil is by the _______________ method?
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A. Junkers calorimeter

B. Kjeldahl

C. Dumas

D. Bomb calorimeter
3065. CnH2n is the general formula for_______________?
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A. Olefins

B. Naphthenes

C. Both A. and B.

D. Neither A. nor B.

3066. If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process. The diffusivity under this condition is called Knudsen diffusivity, which is affected by the_____________________?
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A. Pressure

B. Temperature

C. Both A. & B.

D. Neither A. nor B.

3067. An isothermal aqueous phase reversible reaction, P ? R, is to be carried out in a mixed flow reactor. The reaction rate in k.mole/m3 .h is given by, r = 0.5CP 0.125CR. A stream containing only P enters the reactor. The residence time required (in hours) for 40% conversion of P is_________________?
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A. 1.33

B. 1.60

C. 0.8

D. 2.67

3068. Carbon particles accumulated on the catalyst used in the gas oil cracking lies in the category of _____________________ poison?
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A. Stability

B. Selectivity

C. Deposited

D. Chemisorbed

3069. Reaction of benzene with chlorine gas to produce tri-chlorobenzene exemplifies a/an ______________ reaction?
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A. Elementary

B. None of these

C. Parallel

D. Consecutive
3070. A backmix reactor_________________?
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A. Employs mixing in axial direction only

B. Is same as plug-flow reactor

C. Is same as ideal stirred tank reactor

D. Is most suitable for gas phase reaction

3071. Backmixing is most predominant in___________________?
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A. CSTRs connected in series

B. A plug-flow reactor

C. A well stirred batch reactor

D. A single CSTR
3072. The catalytic activity of enzymes is due to their capacity to lower the ______________ energy?
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A. Potential

B. Activation

C. None of these

D. Kinetic

3073. Which of the following is desirable in diesel and kerosene but is undesirable in gasoline ?
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A. Mercaptans

B. Aromatics

C. Naphthenic acid

D. Paraffins

3074. What is the unit of the rate constant in a chemical reaction in which 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on ?
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A. Litre/mole

B. Litre/mole.second

C. Moles/litre.second

D. Litre/second

3075. If the pore diffusion controls in a catalytic reaction, the apparent activation energy Ea is equal to___________________?
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A. (E + ED)/2

B. The intrinsic activation energy E

C. (E + ED) where ED is activation due to diffusion

D. ED/2
3076. Which of the following is a controlling factor in very fast heterogeneous reaction ?
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A. Temperature

B. Heat and mass transfer effects

C. Pressure

D. Composition of reactant

3077. 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________________?
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A. 0

B. 1

C. > 1

D. ?

3078. In the reversible reaction of the type, A + B ? AB, in general__________________?
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A. Both forward and backward reactions will be exothermic

B. Neither of the reactions will be endothermic

C. The combination reaction will be exothermic, while the dissociation reaction will be

D. othermic</strong>

E. The combination reaction will be endothermic, while the dissociation reaction will be

F. thermic

3079. The importance of diffusion in a catalyst are increased by ____________________?
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A. All A., B. and C.

B. An active surface of the catalyst

C. Large catalyst particle size

D. Small pore diameter

3080. In a reversible reaction, a catalyst increases the rate of forward reaction__________________?
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A. And the backward reaction equally

B. Only

C. To a greater extent than that of the backward reaction

D. And decreases that of the backward reaction

3081. Space time equals the mean residence time__________________?
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A. For large diameter tubular reactor

B. When the density of the reaction mixture is constant

C. For narrow diameter tubular reactor

D. For CSTR

3082. Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the ___________________?
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A. None of these

B. Activation energy

C. Equilibrium constant

D. Heat of reaction

3083. Half-life period for a first order reaction is _____________ the initial concentration of the reactant?
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A. Independent of

B. None of these

C. Inversely proportional to

D. Directly proportional to

3084. Pressure & temperature maintained in catalytic cracking is about__________________?
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A. 50 atm & 750C

B. 2 atm & 500C

C. 30 atm & 200C

D. 10 atm & 500C

3085. Which of the following is not a chemical step in a fluid solid catalytic reaction ?
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A. None of these

B. Desorption

C. Adsorption

D. Surface chemical reaction

3086. The single parameter model proposed for describing non-ideal flow is the ____________ model?
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A. Tank in series

B. Dispersion

C. Both A. & B.

D. Neither A. nor B.

3087. The rate of forward reaction, at chemical equilibrium is ______________ the rate of backward reaction?
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A. More than

B. Less than

C. Equal to

D. Either B. or C.

3088. For the liquid phase zero order irreversible reaction A ? B, the conversion of A in a CSTR is found to be 0.3 at a space velocity of 0.1min-1. What will be the conversion for a PFR with a space velocity of 0.2 min-1? Assume that all the other operating conditions are the same for CSTR and PFR ?
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A. 0.3

B. 0.60

C. 0.9

D. 0.15

3089. The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is________________________?
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A. Series of CSTR

B. Plug flow reactor

C. Backmix reactor

D. PFR in series

3090. Slurry reactors are characterised by the_________________?
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A. Lack of intraparticle diffusion resistance

B. Presence of two mobile phases

C. Both A. and B.

D. Neither A. nor B.

3091. LPG stands for ____________________?
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A. Liquefied petroleum gas

B. Liquid petroleum gas

C. Liquid petrol gas

D. Liquefied petrol gas

3092. Catalyst used in isomerisation process is __________________ ?
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A. HF

B. H2SO4

C. AlCl3

D. H3PO4

3093. Molecularity of a reaction__________________?
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A. Is always equal to the overall order of reaction

B. May not be equal to the order of reaction

C. Cant have a fractional value

D. Both B. and C.
3094. Higher boiling fractions like atmospheric residue is distilled under vacuum at low temperature because at high temperature, there is a tendency of the predominance of ____________________?
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A. Discoloration

B. Thermal cracking

C. Gum formation

D. Coking
3095. The dimensions of rate constant for reaction 3A ? B are (l/gm mole)/min. Therefore the reaction order is______________________?
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A. 2

B. 3

C. 0

D. 1

3096. Sometimes, batch process is preferred over continuous process, when the product___________________?
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A. Quality & yield cannot be achieved in continuous processes, because of long residence time

B. Sales demand is fluctuating

C. Both A. & B.

D. Neither A. nor B.

3097. Tanks used for the storage of petroleum products (which are inflammable) should be painted with a ______________ paint?
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A. White

B. Yellow

C. Black

D. Red

3098. Exothermic reactions are best carried out in ________________?
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A. A plug flow reactor followed by CSTR

B. A CSTR

C. CSTR in series

D. CSTR followed by a plug flow reactor
3099. The characterisation factor of crude petroleum oil is around__________________?
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A. 22

B. 11

C. 28

D. 3

3100. Pick the WRONG design guideline for a reactor in which the reactions, A ? R (desired) and A ? S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k1/k2). CA a-b ?
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A. Use high pressure and eliminate inerts, when a > b

B. Use CSTR with a high conversion, when a > b

C. Use batch reactor or plug flow reactor, when a > b

D. Avoid recycle, when a > b