81. When the reaction is dominated by in-traparticle diffusion, the apparent order of reaction (nD) as measured is related to the true order (n) as
ND = (n + 1)/2
ND = n/2
ND = n + 1
None of these
✅ The correct answer is option A.
Chemical Reaction Engineering MCQs
82. Arhenious equation shows the variation of __________ with temperature.
Reaction rate
Rate constant
Energy of activation
Frequency factor
✅ The correct answer is option B.
83. A back mix reactor is
Suitable for gas phase reactions
Ideal at very low conversion
Same as plug flow reactor (PFR)
Same as ideal stirred tank reactor
✅ The correct answer is option D.
84. If in the gaseous phase reaction, N₂O₄ ⇋ 2NO₂, x is the part of N₂O₄ which dissociates, then the number of molecules at equilibrium will be
(1 + x)
(1 – x)
(1 + x)²
(1 – x)²
✅ The correct answer is option A.
85. The dimensions of rate constant for reaction 3A → B are (l/gm mole)/min. Therefore the reaction order is
0
1
2
3
✅ The correct answer is option C.
86. The decomposition of A into B is represented by the exothermic reaction, A ⇋ 2B. To achieve maximum decomposition, it is desirable to carry out the reaction.
At high P and high T
At low P and high T
At low P and low T
At high P and low T
✅ The correct answer is option C.
87. The excess energy of the reactants required to dissociate into products is known as the __________ energy.
Thermal
Activation
Threshold
Binding
✅ The correct answer is option B.
88. In case of staged packed bed reactors carrying out exothermic reaction, use
High recycle for pure gas
Plug flow for dilute liquid requiring no large preheating of feed
Cold shot operations for a dilute solution requiring large preheating to bring the stream upto the reaction temperature
All of the above
✅ The correct answer is option D.
89. For a packed bed reactor; the presence of a long tail in the residence time distribution curve is an indication of
Ideal plug flow
Bypass
Dead zone
Chanelling
✅ The correct answer is option C.
90. 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
0
1
2
3
✅ The correct answer is option C.