Q.1

In a semi-batch reactor,

  • mixing takes place in axial direction only.
  • velocity of reaction can be controlled.
  • condition similar to plug flow reactor exists.
  • residence time is constant.
Q.2

The most unsuitable reactor for carrying out reactions in which high reactant concentration favours high yields is

  • backmix reactor
  • plug flow reactor
  • series of CSTR
  • PFR in series
Q.3

Half life period of a chemical reaction is

  • the time required to reduce the concentration of the reacting substance to half its initial value.
  • half of the space time of a reaction.
  • half of the residence time of a reaction.
  • none of these
Q.4

For high conversion in a highly exothermic solid catalysed reaction, use a __________ bed reactor.

  • fixed
  • fluidised bed reactor followed by a fixed
  • fixed bed reactor followed by a fluidised
  • fluidised
Q.5

For an autocatalytic reactor, the suitable reactor set up is

  • P.F. reactors in series.
  • CSTR in series.
  • CSTR followed by P.F. reactor.
  • P.F. reactor followed by CSTR.
Q.6

Ionic reactions occur in

  • solid state only
  • liquid state only
  • solutions
  • any state
Q.7

Most important characteristics of gas-liquid reactors are the

  • specific inter-facial area
  • liquid hold-up
  • both (a) and (b)
  • none of these
Q.8

Pick out the wrong statement pertaining to space velocity of flow reactors.

  • The unit of space velocity is (time)-1 .
  • The space velocity of 3 hr-1 means that three reactor volumes of feed at specified conditions are being fed into the reactor every hour.
  • The space velocity of 3 hr-1 means that one third reactor volume of feed at specified conditions are being fed into the reactor.
  • none of these.
Q.9

Transition state theory relates the above quantities as

  • k ∝ e-E/RT
  • k ∝ T.eE/RT
  • k ∝ T
  • k ∝ T1.5
Q.10

For every 10°C rise in temperature, the rate of chemical reaction doubles. When the temperature is increased fromto 70°C, the rate of reaction increases __________ times.

  • 8
  • 12
  • 16
  • 32
Q.11

Sometimes, batch process is preferred over continuous process, when the product

  • quality & yield can not be achieved in continuous processes, because of long residence time.
  • sales demand is fluctuating.
  • both (a) & (b).
  • neither (a) nor (b).
Q.12

Transition state theory relates the above quantities as

  • k ∝ e-E/RT
  • k ∝ T.eE/RT
  • k ∝ T
  • k ∝ T1.5
Q.13

A reactor is generally termed as an autoclave, when it is a

  • high pressure batch reactor.
  • atmospheric pressure tank reactor.
  • high pressure tubular reactor.
  • atmospheric pressure CSTR.
Q.14

The single parameter model proposed for describing non-ideal flow is the __________ model.

  • tank in series
  • dispersion
  • both (a) & (b)
  • neither (a) nor (b).
Q.15

A first order reaction requires two equal sized CSTR. The conversion is

  • less when they are connected in series.
  • more when they are connected in series.
  • more when they are connected in parallel.
  • same whether they are connected in series or in parallel.
Q.16

6 gm of carbon is burnt with an amount of air containinggm oxygen. The product contains 16.5 gms CO2 and 2.8 gms CO besides other constituents. What is the degree of conversion on the basis of disappearance of limiting reactant ?

  • 100%
  • 95%
  • 75%
  • 20%
Q.17

Transition state theory relates the above quantities as

  • k ∝ e-E/RT
  • k ∝ T.eE/RT
  • k ∝ T
  • k ∝ T1.5
Q.18

A first order reaction requires two equal sized CSTR. The conversion is

  • less when they are connected in series.
  • more when they are connected in series.
  • more when they are connected in parallel.
  • same whether they are connected in series or in parallel.
Q.19

Most important characteristics of gas-liquid reactors are the

  • specific inter-facial area
  • liquid hold-up
  • both (a) and (b)
  • none of these
Q.20

The reaction in which one of the products of reaction acts as a catalyst is called a/an __________ reaction.

  • biochemical
  • photochemical
  • catalytic
  • autocatalytic
Q.21

The rate at which a chemical substance reacts is proportional to its

  • active mass
  • equivalent weight
  • molecular weight
  • none of these
Q.22

A batch reactor is characterised by

  • constant residence time.
  • variation in extent of reaction and properties of the reaction mixture with time.
  • variation in reactor volume.
  • very low conversion.
Q.23

A typical example of an exothermic reversible reaction conducted at high pressure in industry is

  • dehydration of ethanol.
  • methanol synthesis.
  • reformation of methane.
  • polymerisation of ethylene.
Q.24

Study of chemical kinetics is the easiest in the case of __________ reactions.

  • irreversible
  • reversible
  • surface
  • side
Q.25

The 'E' curve for a non-ideal reactor defines the fraction of fluid having age between t and t + dt

  • at the inlet
  • at the outlet
  • in the reactor
  • averaged over the inlet and outlet
Q.26

An imbalanced chemical reaction equation is against the law of

  • multiple proportion
  • conservation of mass
  • constant proportion
  • none of these
Q.27

A plug-flow reactor is characterised by

  • high capacity.
  • presence of axial mixing.
  • presence of lateral mixing.
  • constant composition and temperature of reaction mixture.
Q.28

Which of the following is the most suitable for very high pressure gas phase reaction ?

  • Batch reactor
  • Tubular flow reactor
  • Stirred tank reactor
  • Fluidised bed reactor
Q.29

A batch reactor is characterised by

  • constant residence time.
  • variation in extent of reaction and properties of the reaction mixture with time.
  • variation in reactor volume.
  • very low conversion.
Q.30

When a catalyst increases the rate of forward reaction, the value of rate constant

  • increases
  • decreases
  • remain same
  • becomes infinite
Q.31

Rate determining step in a reaction consisting of a number of steps in series is the __________ step.

  • fastest
  • slowest
  • intermediate
  • data insufficient; can't be predicted
Q.32

In autocatalytic reactions,

  • one of the reactants acts as a catalyst.
  • one of the products acts as a catalyst.
  • catalysts have very high selectivity.
  • no catalyst is used.
Q.33

Pick out the wrong statement.

  • The integral method of analysing kinetic data is used when the data is scattered.
  • The differential method of analysing kinetic data requires more accurate or larger amounts of data.
  • When the reaction rate is independent of temperature, the reaction is said to be of zero order.
  • The ratio of volumes of plug flow reactor to that of mixed reactor is always less than one for identical feed composition, flow rate, conversion and for all positive reaction orders.
Q.34

Rate determining step in a reaction consisting of a number of steps in series is the __________ step.

  • fastest
  • slowest
  • intermediate
  • data insufficient; can't be predicted
Q.35

A batch reactor is

  • suitable for gas-phase reactions on commercial scale.
  • suitable for liquid phase reactions involving small production rate.
  • least expensive to operate for a given rate.
  • most suitable for very large production rate.
Q.36

Which of the following is a characteristic of an ideal plug flow reactor ?

  • Axial dispersion
  • Flat velocity profile
  • Uniform mixing
  • None of these
Q.37

The rate constant of a chemical reaction decreases by decreasing the

  • pressure
  • concentration of reactants
  • temperature
  • duration of reaction
Q.38

The increase in the rate of reaction with temperature is due to

  • increase in the number of effective collisions.
  • decrease in activation energy.
  • increase in the average kinetic energy of the reacting molecules.
  • none of these.
Q.39

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.
Q.40

The reaction between oxygen and organic material is a/an __________ reaction.

  • exothermic
  • endothermic
  • biochemical
  • photochemical
Q.41

A batch reactor is

  • suitable for gas-phase reactions on commercial scale.
  • suitable for liquid phase reactions involving small production rate.
  • least expensive to operate for a given rate.
  • most suitable for very large production rate.
Q.42

Semibatch reactor is preferred, when a/an

  • a highly exothermic reaction is to be controlled.
  • undersirable side reaction (at high concentration of one of the reactants) is to be avoided.
  • a gas is to be reacted with liquid (e.g. hydrogenation of fat).
  • all (a), (b), and (c).
Q.43

For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the __________ adsorption.

  • physical
  • chemical
  • both (a) and (b)
  • neither (a) nor (b)
Q.44

Sulphuric acid is used as a catalyst in the

  • hydrogenation of oils.
  • gas phase oxidation of SO2 in chamber process.
  • alkylation of hydrocarbons.
  • none of these.
Q.45

Which of the following will give maximum gas conversion ?

  • Fixed bed reactor.
  • Fluidised bed reactor.
  • Semi-fluidised bed reactor.
  • Plug-flow catalytic reactor.
Q.46

A reaction which is catalysed by an acid is also catalysed by any substance, which has a tendency to

  • lose a proton.
  • gain a proton.
  • lose an electron
  • none of these.
Q.47

The catalyst in a second order reversible reaction increases the rate of the forward reaction

  • and decreases that of backward reaction.
  • and backward reaction equally.
  • only.
  • to a greater extent than that of the backward reaction.
Q.48

A backmix reactor

  • is same as plug-flow reactor.
  • is same as ideal stirred tank reactor.
  • employs mixing in axial direction only.
  • is most suitable for gas phase reaction.
Q.49

Velocity of a reaction depends upon the

  • nature of the reactants.
  • concentration of the reactants.
  • temperature at which the reaction is carried.
  • all (a), (b) and (c).
Q.50

A reversible liquid phase endothermic reaction is to be carried out in a plug flow reactor. For minimum reactor volume, it should be operated such that the temperature along the length

  • decreases.
  • increases.
  • is at the highest allowable temperature throughout.
  • first increases and then decreases.
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