91. Backmixing is most predominant in
A well stirred batch reactor
A plug-flow reactor
A single CSTR
CSTR’s connected in series
✅ The correct answer is option C.
Chemical Reaction Engineering MCQs
92. Specific rate constant for a second order reaction
Is independent of temperature
Varies with temperature
Depends on the nature of the reactants
Both B and C
✅ The correct answer is option D.
93. Pure A in gas phase enters a reactor 50% of this A is converted to B through the reaction, A 3B. Mole fraction of A in the exit stream is
1-Feb
1-Mar
1-Apr
1-May
✅ The correct answer is option C.
94. In a reaction, the threshold energy is equal to (where, A = activation energy N = normal energy of reactants)
A
N
A+N
A-N
✅ The correct answer is option C.
95. Ionic reactions occur in
Solid state only
Liquid state only
Solutions
Any state
✅ The correct answer is option C.
96. Rate of a chemical reaction is not affected by the
Catalyst
Temperature
Reactant’s concentration
Number of molecules of reactants taking part in the reaction
✅ The correct answer is option D.
97. The half life period of a first order reaction is
Always the same irrespective of the reaction
Dependent on initial concentration of the reactants
Proportional to the initial concentration of reactants
Half the specific rate constant
✅ The correct answer is option B.
98. Fractional conversion __________ with increase in pressure for ammonia synthesis reaction i.e., N₂ + 3H₂ ⇋ 2NH₃.
Increases
Decreases
Remains unchanged
Unpredictable from the data
✅ The correct answer is option A.
99. For reactions in parallel viz A → P (desired product) and A → Q (unwanted product), if the order of the desired reaction is higher than that of the undesired reaction, a
Batch reactor is preferred over a single CSTR for high yield
Tubular reactor is preferred over a single CSTR for high yield
Both A and B
Single CSTR is the most suitable
✅ The correct answer is option C.
100. An example of autothermal reactor operation is
Sulphur dioxide oxidation
Ethylene oxidation
Benzene oxidation
Ammonia synthesis
✅ The correct answer is option B.