Lessens its selectivity
May be useful for suppressing undesirable side reactions
Is added in small quantity during the catalyst manufacture itself
All of the above
✅ The correct answer is option D.
Chemical Engineering MCQs
Enzymes are destroyed, when the
Temperature is very high
Reactant’s concentration is very high
Reactant’s concentration is very low
Reaction rate is independent of the reactant’s concentration
✅ The correct answer is option A.
Holding time for flow reactors is __________ the space time, for constant fluid density
Double
Triple
Equal to
None of these
✅ The correct answer is option C.
Batch process is preferred over continuous process, when the
Product yields and quality can not be achieved in continuous process, because of long residence time
Sales demand of product is not steady
Same equipment can not be used for several processes of the same nature
All of the above
✅ The correct answer is option D.
For a tubular reactor with space time ‘τ’ and residence time ‘θ’, the following statement holds good.
τ and θ are always equal
τ = θ , when the fluid density changes in the reactor
τ = θ , for an isothermic tubular reactor in which the density of the process fluid is constant
τ = θ , for a non-isothermal reactor
✅ The correct answer is option C.
In the reversible reaction of the type, A + B ⇋ AB, in general
Both forward and backward reactions will be exothermic
Neither of the reactions will be en-dothermic
The combination reaction will be exothermic, while the dissociation reaction will be endothermic
The combination reaction will be endothermic, while the dissociation reaction will be exothermic
✅ The correct answer is option C.
The half life period of a first order reaction is given by (where, K = rate constant. )
1.5 K
2.5 K
0.693/K
6.93 K
✅ The correct answer is option C.
The energy of activation of a chemical reaction
Is same as heat of reaction at constant pressure
Is the minimum energy which the molecules must have before the reaction can take place
Varies as fifth power of the temperature
Both B and C
✅ The correct answer is option B.
For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, when the __________ is the controlling resistance.
Film diffusion
Diffusion through ash layer
Chemical reaction
Either A, B or C
✅ The correct answer is option B.
In an exothermic reaction, the energy of the reacting substances as compared to that of products is
More
Less
Same
Either A or B, depends on order of reaction
✅ The correct answer is option A.