Chemical Reaction Engineering MCQs

Question 1

In case of a _____________ reactor, the composition in the reactor and at the exit of the reactor is the same ?

Accepted Answer

Back-mix

Answer

Semi-batch

Answer

Tubular

Answer

Batch

Question 2

Catalytic action in a catalytic chemical reaction follows from the ability of catalyst to change the ___________________?

Accepted Answer

Activation energy

Answer

Equilibrium constant

Answer

Heat of reaction

Answer

None of these

Question 3

Reaction of benzene with chlorine gas to produce tri-chlorobenzene exemplifies a/an ______________ reaction?

Accepted Answer

Consecutive

Answer

Parallel

Answer

Elementary

Answer

None of these

Question 4

In which of the following gaseous phase reversible reactions, the product yield cannot be increased by the application of high pressure ?

Accepted Answer

N2 + O2 ⇌ 2NO

Answer

PCl3 + Cl2 ⇌ PCl5

Answer

N + 3H2 ⇌ 2NH3

Answer

2SO2 + O2 ⇌ 2SO3

Question 5

When an exothermic reversible reaction is conducted adiabatically, the rate of reaction____________________?

Accepted Answer

Passes through a maximum

Answer

Continuously increases

Answer

Continuously decreases

Answer

Passes through a minimum

Question 6

Reactions with high activation energy are_____________________?

Accepted Answer

Very temperature sensitive

Answer

Temperature insensitive

Answer

Always irreversible

Answer

Always reversible

Question 7

For a mixed flow reactor operating at steady state, the rate of reaction is given by______________?

Accepted Answer

(FA0/V) XA

Answer

(FA0/V) - (dCA/dt)

Answer

(FA0/V) + (dCA/dt)

Answer

-(dCA/dt)

Question 8

With increase in the order of reaction (for all positive reaction orders), the ratio of the volume of mixed reactor to the volume of plug flow reactor (for identical feed composition, flow rate and conversion)?

Accepted Answer

Increases

Answer

Remain same

Answer

Decreases

Answer

Increases linearly

Question 9

The rate equation for the reaction represented by as shown in the bellow figure, is given by - rx = K1 . Cx/(1 + K2 Cx). At high value of Cx (i.e.., K2Cx > > 1), the order of the reaction and the rate constant are respectively___________________?

Accepted Answer

Zero order & K1/K2

Answer

Zero order & K1

Answer

First order & K1

Answer

First order & K1/K2

Question 10

What is the dispersion number for a plug flow reactor ?

Accepted Answer

0

Answer

∞

Answer

1

Answer

-1

Question 11

Transition state theory gives the rate constant as__________________?

Accepted Answer

K α T . e-E/RT

Answer

K α e-E/RT

Answer

K α eE/RT

Answer

K α √T . e-E/RT

Question 12

From collision theory, the reaction rate constant is proportional to_________________?

Accepted Answer

Tm exp (-E/RT)

Answer

exp (-E/RT)

Answer

exp (-E/2RT)

Answer

√T

Question 13

The unit of frequency factor in Arrhenius equation is_______________?

Accepted Answer

Same as that of rate constant

Answer

Same as that of activation energy

Answer

Dimensionless

Answer

None of these

Question 14

The ratio of moles of a reactant converted into the desired product to that converted into unwanted product is called_________________?

Accepted Answer

Selectivity

Answer

Operational yield

Answer

Relative yield

Answer

None of these

Question 15

Space time equals the mean residence time__________________?

Accepted Answer

When the density of the reaction mixture is constant

Answer

For CSTR

Answer

For large diameter tubular reactor

Answer

For narrow diameter tubular reactor

Question 16

Chemical reaction rate of a component depends upon the______________________?

Accepted Answer

All A., B. and C.

Answer

Temperature of the system

Answer

Pressure of the system

Answer

Composition of the component only

Question 17

For a first order reaction carried out in a plug flow reactor, the space time is__________________?

Accepted Answer

(1/k) ln C0/C

Answer

(1/k) ln C/C0

Answer

k ln C0/C

Answer

k ln C/C0

Question 18

A space time of 3 hours for a flow reactor means that___________________?

Accepted Answer

The time required to process one reactor volume of feed (measured at specified conditions) is

Answer

3 hours

Answer

Three reactor volumes of feed can be processed every hour

Answer

It takes three hours to dump the entire volume of the reactor with feed

Answer

Conversion is cent per cent after three hours

Question 19

A CSTR is to be designed in which an exothermic liquid phase first order reaction of the type, A → R, is taking place. The reactor is to be provided with a jacket in which coolant is flowing. Following data is given: CA0= 5 kmole/m3; XA = 0.5; Feed temperature = reactor temperature = 40°C. Rate constant at 40°C = 1 min-1; (ΔH) = - 40kJ/mole; ρ = 1000kg/m3 CP = 4 J/gm.°C ; q = 10-3 m3/min (ρ and CP are same for the reactant and product streams). The amount of heat to be removed is_________________?

Accepted Answer

5/3 kW

Answer

2/3 kW

Answer

1 kW

Answer

4 kW

Question 20

If n = overall order of a chemical reaction. a = initial concentration of reactant. t = time required to complete a definite fraction of the reaction. Then pick out the correct relationship ?

Accepted Answer

t ∝ 1/an - 1

Answer

t ∝ 1/an

Answer

t ∝ 1/an + 1

Answer

t ∝ an

Free Chemical Reaction Engineering MCQs with Answers