chemical engineering chemical reaction MCQs – Page 4

Practise multiple-choice questions from chemical engineering chemical reaction for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering chemical reaction Mcqs
61. What is the order of a chemical reaction of the bellow figure, if the rate of formation of C, increases by a factor of 2.82 on doubling the concentration of A and increases by a factor of 9 on trebling the concentration of B ?
comments icon0
A. 7/2

B. 4-May

C. 4-Jul

D. 2-May

62. Promoter_____________________?
comments icon0

A. ating discontinuities in the crystals</strong>

B. Increases the number of active centres by increasing the unevenness of catalyst surface and by

C. Alters the position of equilibrium in a reversible reaction

D. All A., B. and C.

E. Initiates a chemical reaction and is a catalyst by itself

63. A chemical reaction, A ? 3B, is conducted in a constant pressure vessel. Starting with pure A, the volume of the reaction mixture increases 3 times in 6 minutes. The fractional conversion is ___________________?
comments icon0

A. Data insufficient, cant be predicted

B. 1

C. 0.33

D. 0.5

64. The reactions with low activation energy are _____________________?
comments icon0

A. Slow

B. Fast

C. Always spontaneous

D. Non-spontaneous

65. The rate at which a chemical substance reacts is proportional to its____________________?
comments icon0

A. Equivalent weight

B. Molecular weight

C. Active mass

D. None of these

66. BET apparatus is used to determine the ___________________?
comments icon0

A. Pore diameter

B. Specific surface of a porous catalyst

C. Pore size distribution

D. Porosity of the catalyst bed

67. A stirred tank reactor compared to tubular-flow reactor provides____________________?
comments icon0

A. Higher overall selectivity for a first order consecutive reaction

B. More uniform operating conditions

C. All A., B. and C.

D. Permits operation at the optimum temperature for a long reaction time

68. The order of a chemical reaction is__________________?
comments icon0

A. Always equal to the total stoichiometric number of reactants

B. Never fractional

C. None of these

D. An experimentally determined quantity
69. For a heterogeneous catalytic reaction, A + B ? C, with equimole feed of A and B, the initial rate rA0 is invariant with total pressure. The rate controlling step is______________________?
comments icon0
A. Desorption of C

B. Surface reaction between absorbed A and absorbed B

C. Surface reaction between A in the gas phase and absorbed B

D. Surface Kc/(1 + TS) reaction between absorbed A and B in the gas phase

70. Three plug flow reactors (PFRs) of 4, 5 & 6 m3 volumes are arranged in two branches as shown below in the figure. If the total feed rate is 300 tons/hr, then for the same conversion in each branch, the feed rate through branch II should be ______________ tons/hr ?
comments icon0
A. 100

B. 150

C. 225

D. 200

71. Cold shot cooling is only practical when the feed temperature is ______________ than the reaction temperature?
comments icon0

A. Higher

B. Lower

C. Much higher

D. Much lower
72. Which of the following is not endothermic in nature ?
comments icon0

A. Steam reforming of naphtha

B. Gasification of carbon

C. Thermal cracking of fuel oil

D. Combustion of sulphur
73. The exit age distribution of a fluid leaving a vessel (denoted by E) is used to study the extent of non-ideal flow in the vessel. The value of ?? 0 E.dt is____________________?
comments icon0

A. ?

B. 0

C. 1

D. ?2?

74. A reaction which is catalysed by an acid is also catalysed by any substance, which has a tendency to _________________?
comments icon0
A. Lose a proton

B. None of these

C. Lose an electron

D. Gain a proton

75. Time required for 50% decomposition of a liquid in an isothermal batch reactor following first order kinetics is 2 minutes. The time required for 75% decomposition will be about _______________ minutes?
comments icon0

A. 10

B. 6

C. 4

D. 3

76. With the same reaction time, initial concentration and feed rate, the reaction 2A ? B is carried out separately in CSTR and P.F. reactor of equal volumes. The conversion will be__________________?
comments icon0
A. Higher in P.F. reactor

B. Higher in CSTR

C. Same in both the reactors

D. Data insufficient; cant be predicted

77. Calcination reaction of limestone (CaCO3 ? CaO + CO2) goes to completion in the rotary kiln, because____________________?
comments icon0

A. Of high calcination temperature

B. CO2 escapes continuously

C. CaO is more stable than CaCO3

D. CaO is not dissociated

78. In case of a P.F.R., there__________________________?
comments icon0

A. May be lateral mixing of fluid

B. Should not be any mixing along the flow path

C. Both A. and B.

D. Neither A. nor B.

79. For every 10C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased from 30 to 70C, the rate of reaction increases ______________ times?
comments icon0

A. 12

B. 8

C. 16

D. 32

80. For a zero order reaction, the concentration of product increases with the _____________________?
comments icon0
A. Increase of reaction time

B. Increase in initial concentration

C. Total pressure

D. Decrease in total pressure