REACTOR DESIGN Flashcards
Rate of chemical reaction is independent of the concentration of reactants for
(a) zero order reaction
(b) third order reaction
(c) consecutive reaction
(d) none of these
zero order reaction
Which of the following is not a unit of reaction rate?
(a) moles formed/(surface of catalyst) (time)
(b) moles formed/(volume of reactor) (time)
(c) mole formed/(volume of catalyst) (time)
(d) none of these
none of these
If “n” is the order of reaction then unit of rate constant is
(a) 1/
(time) (concentration)n-1
(b) (time)-1(concentration)n-1
(c) (time)n-1 (concentration)
(d) none of these
(a) 1/
(time) (concentration)n-1
Which of the following is a controlling factor in very fast heterogeneous reaction?
(a) heat and mass transfer effects
(b) pressure
(c) temperature
(d) composition of reactant
heat and mass transfer effects
Rate determining step in a reaction consisting of a number of step in series is the
(a) fastest step
(b) slowed step
(c) intermediate step
(d) data insufficient; can’t be predict
slowed step
Variables affecting the rate of homogeneous reactions are
(a) pressure and temperature only
(b) temperature and composition only
(c) pressure and composition only
(d) pressure, temperature and composition
pressure, temperature and composition
Chemical kinetics can predict the
(a) rate of reaction
(b) feasibility of reaction
(c) both (a) and (b)
(d) none of these
rate of reaction
Velocity of a chemical reaction
(a) decreases with increase in temperature
(b) increases with increase of pressure of reactant for all reactions
(c) decreases with increase of reactant concentration
(d) none of these
none of these
Sum of the powers of the concentration terms in the rate equation is called the
(a) order of the reaction
(b) overall order of the reaction
(c) molecularity of the reaction
(d) none of these
overall order of the reaction
Molecularity of a reaction
(a) is always equal to the overall order of reaction
(b) may not be equal to the order of reaction
(c) can’t have a fractional value
(d) both (b) and (c)
both (b) and (c)
Inversion of cane sugar is an example of
(a) unimolecular reaction with first order
(b) bimolecular reaction with second order
(c) bimolecular reaction with first order
(d) unimolecular reaction with second order
bimolecular reaction with first order
Concentration of the limiting reactant (with initial concentration of a moles/liter) after time t is (a-x).Then t for a first order reaction is given by
(a) kt = ln (a/a-x)
(b) kt = x/a(a-x)
(c) kt = ln (a-x/a)
(d) k.t = a (a-x)/x
kt = ln (a/a-x)
Half life period of a chemical reaction is
(a) the time required to reduce the concentration of the reacting substance to half its initial value
(b) half of the space time of a reaction
(c) half of the residence time of a reaction
(d) none of these
the time required to reduce the concentration of the reacting substance to half its initial value
Fill up the blanks:
Half-life period for a first order reaction is………………….. the initial concentration of the reactant
(a) directly proportional to
(b) inversely proportional to
(c) independent of
(d) none of these
independent of
Fill up the blanks from among the alternatives given below: In a first order reaction the time required to reduce the concentration of reactant from 1 mole/liter to 0.5 mole/liter will be …………. that required to reduce it from 10 moles/liter to 5 moles/liter in the same volume
(a) more than
(b) less than
(c) same as
(d) data insufficient; can’t be predicted
same as
Specific rate constant for a second order reaction
(a) is independent of temperature
(b) varies with temperature
(c) depends on the nature of the reactants
(d) both (b) and (c)
both (b) and (c)
The reaction in which rate equation corresponds to a stoichiometric equation is called
(a) elementary reaction
(b) non-elementary reaction
(c) parallel reaction
(d) autokinetic reaction
elementary reaction
Equilibrium of a chemical reaction as viewed by kinetics is a
(a) dynamic steady state
(b) static steady state
(c) dynamic unsteady state
(d) none of these
dynamic steady state
For a zero order reaction, concentration of product increases with
(a) increase of reaction time
(b) increase in initial concentration
(c) total pressure
(d) decrease in total pressure
increase of reaction time
Fill up the blanks
Arrhenius equation shows the variation of __________with temperature
(a) Reaction rate
(b) Rate constant
(c) Energy of activation
(d) Frequency factor
Rate constant
The energy of activation of a chemical reaction
(a) is same as heat of reaction at constant pressure
(b) is the minimum energy which the molecules must have before the reaction can take place
(c) varies as fifth power of the temperature
(d) both (b) and (c)
is the minimum energy which the molecules must have before the reaction can take place
Rate constant ‘k’ and the absolute temperature T are related by collision theory (for bimolecular) as
(a) k T 1.5
(b) k e –E/RT
(c) k T
(d) k T
k T
Transition state theory relates the above quantities as
(a) k e –E/RT
(b) k Te –E/RT
(c) k T
(d) k T 1.5
NO ANSWER
Reactions with high activation energy are
(a) very temperature sensitive
(b) temperature insensitive
(c) always irreversible
(d) always reversible
very temperature sensitive
In autocalytic reactions
(a) one of the reactants acts as a catalyst
(b) one of the products acts as a catalyst
(c) catalyst has very high selectivity
(d) no catalyst is used
one of the products acts as a catalyst
With increase in temperature, the equilibrium conversion of a reversible exothermic reaction
(a) decreases
(d) increases
(c) remain unaffected
(d) decreases linearly with temperature
decreases
With decrease in temperature, the equilibrium conversion of a reversible endothermic reaction
(a) decreases
(b) increases
(c) remains unaffected
(d) increases linearly with temperature
decreases
The equilibrium constant of a chemical reaction
(a) increases in the presence of catalyst
(b) decreases in the presence of catalyst
(c) remains unaffected in the presence of a catalyst
(d) can either increase or decrease; depends on the type of catalyst
remains unaffected in the presence of a catalyst
Conversion increases with increase in temperature of
(a) Autocatalytic reaction
(b) Irreversible reaction
(c) Reversible endothermic reaction
(d) Reversible exothermic reaction
Reversible endothermic reaction
The heat of reaction
(a) depends on the pressure only
(b) depends on the mechanism of reaction only
(c) depends on both pressure and mechanism of reaction
(d) is independent of the mechanism of reaction
is independent of the mechanism of reaction
Integral method for analyzing the kinetic data is used
(a) when the data are scattered
(b) for testing specific mechanisms with simple rate expression
(c) both (a) and (b)
(d) none of these
both (a) and (b)
Differential method for analyzing the kinetic data is used
(a) for testing complicated mechanisms
(b) when the data are scattered
(c) when rate expressions are very simple
(d) none of these
for testing complicated mechanisms
Exposure of a photographic plate to produce a latent image is an example of
(a) Very slow reaction
(b) Very fast reaction
(c) Photochemical reaction
(d) Both (b) and (c)
Both (b) and (c)
A trickle bed reactor is one which
(a) has altogether three streams either entering or leaving
(b) processes three reactants at different flow rates
(c) processes three reactant with same flow rate
(d) employs all the three phases (i.e. solid liquid and gas)
employs all the three phases (i.e. solid liquid and gas)
According to Arrhenius equation of temperature dependency of rate constant for an elementary reaction
(a) k T
(b) k e-E/RT
(c) k Te-E/RT
(d) none of these
k e-E/RT
With increases in temperature, the rate constant obeying Arrhenius equation
(a) increases
(b) decreases
(c) decreases exponentially with temperature
(d) can either increase or decrease, depends on the frequency factor
increases
A batch reactor is characterized by
(a) constant residence time
(b) the variation in extent of reaction and properties of the reaction mixture with time
(c) variation in reactor volume
(d) very low conversion
the variation in extent of reaction and properties of the reaction mixture with time
A plug-flow reactor is characterized by
(a) high capacity
(b) presence of axial mixing
(c) presence of lateral mixing
(d) constant composition and temperature of reaction mixture
presence of lateral mixing
In a semi-batch reactor
(a) velocity of reaction can be controlled
(b) maximum conversion can be controlled
(c) both the as reactants flow counter-currently
(d) residence time is constant
velocity of reaction can be controlled
A back mix reactor
(a) is same as plug-flow reactor
(b) is same as ideal stirred tank reactor
(c) employs mixing in axial direction only
(d) is most suitable for gas phase reaction
is same as ideal stirred tank reactor
In a continuous flow stirred tank reactor the composition of the exit stream
(a) is same as that in the reactor
(b) is different than that in the reactor
(c) depends upon the flow rate of inlet stream
(d) none of these
Is same as that in the reactor
In an ideal tubular-flow reactor
(a) there is no mixing in longitudinal direction
(b) mixing takes place in radial direction
(c) there is a uniform velocity across the radius
(d) all (a), (b) and (c)
all (a), (b) and (c)