For a heterogenous 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
A. Surface 1 + T S K C reaction between absorbed A and B in the gas phase
B. Surface reaction between absorbed A and absorbed B
C. Surface reaction between A in the gas phase and absorbed B
D. Desorption of C
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In an ideal P.F.R. at steady state conditions
A. The composition of reactants remains constant along a flow path
B. The conversion of the reactant varies from point to point along a flow path
C. There is no lateral mixing of fluid
D. There may be diffusion along the flow path
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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 r S r R = k 2 k 1 ⋅ C A a − b
A. Use high pressure and eliminate inerts, when a > b
B. Avoid recycle, when a > b
C. Use batch reactor or plug flow reactor, when a > b
D. Use CSTR with a high conversion, when a > b
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The value of steric factor 'P' in the equation k = PZ e RT E usually ranges from
A. L.0 to 10-8
B. L.l. to 102
C. 0.1 to 0.9
D. None of these
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Helium-mercury method can be used to determine the __________ of the catalyst particle.
A. Pore volume
B. Solid density
C. Porosity
D. All of the above
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An exothermic reaction takes place in an adiabatic reactor. The product temperature __________ reactor feed temperature.
A. Is always equal to
B. Is always greater than
C. Is always less than
D. May be greater or less than
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Bulk diffusion in catalyst pore __________ with increase in pressure.
A. Increases
B. Decreases
C. Remains unchanged
D. Increases exponentially
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Chemical kinetics can predict the __________ of a chemical reaction.
A. Rate
B. Feasibility
C. Both A & B
D. Neither A nor B
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The size of plug flow reactor (PFR) for all positive reaction orders and for any given duty, is __________ that of mixed reactor.
A. Greater than
B. Equal to
C. Smaller than
D. Unpredictable from the data
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B.E.T. method can be used to determine the __________ of a porous catalyst.
A. Solid density
B. Pore volume
C. Surface area
D. All of the above
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A first order irreversible reaction, A → B is carried out separately in a constant volume as well as in a variable volume reactor for a particular period. It signifies that __________ in the two reactors.
A. Both conversion as well as concentration are same
B. Conversion in both will be the same but concentrations will be different
C. Both the conversion as well as concentrations will be different
D. None of these
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When all the limiting reactant is consumed in the reaction, the operational yield __________ the relative yield.
A. Is greater than
B. Is smaller than
C. Equals
D. Can be either greater or smaller than (depends on the type of reaction)
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The experimentally determined overall order of the reaction, A + B → C + D, is two. Then the
A. Reaction is elementary with a molecularity of 2
B. Molecularity of the reaction is 2, but the reaction may not be elementary
C. Reaction may be elementary with molecularity of 2
D. Reaction is elementary but the molecularity may not be 2
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In a reaction, the threshold energy is equal to (where, A = activation energy N = normal energy of reactants)
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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?
A. Litre/mole.second
B. Moles/litre.second
C. Litre/mole
D. Litre/second
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A back mix reactor is
A. Suitable for gas phase reactions
B. Ideal at very low conversion
C. Same as plug flow reactor (PFR)
D. Same as ideal stirred tank reactor
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A batch reactor is
A. Suitable for gas-phase reactions on commercial scale
B. Suitable for liquid phase reactions involving small production rate
C. Least expensive to operate for a given rate
D. Most suitable for very large production rate
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A Catalyst
A. Increases the equilibrium concentration of the product
B. Changes the equilibrium constant of the reaction
C. Shortens the time to reach the equilibrium
D. None of these
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A catalyst promoter
A. Improves the activity of a catalyst
B. Acts as a catalyst support
C. Itself has very high activity
D. All of the above
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The equilibrium constant K of a chemical reaction depends on
A. Temperature only
B. Pressure only
C. Temperature and pressure
D. Ratio of reactants
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