Chemical Reaction MCQs

Option A: 3

Option B: 4

Option C: 6

Option D: 10

Correct Answer: 4 ✔

Option A: Diffusion within the pellet

Option B: Reaction

Option C: External mass transfer

Option D: None of the above

Correct Answer: Diffusion within the pellet ✔

Option A: Batch reactor

Option B: Ideal tubular-flow reactor

Option C: Slurry reactor

Option D: CSTR

Correct Answer: Ideal tubular-flow reactor ✔

Option A: Ideal plug flow

Option B: Bypass

Option C: Dead zone

Option D: Channelling

Correct Answer: Dead zone ✔

Option A: Proportional to

Option B: Independent of

Option C: Inversely proportional to

Option D: Proportional to the square of

Correct Answer: Proportional to ✔

Option A: Increases

Option B: Remains unchanged

Option C: Decreases

Option D: Unpredictable from the data

Correct Answer: Decreases ✔

Option A: CSTR of volume V

Option B: PFR of volume V

Option C: CSTR of volume V/X

Option D: PFR of volume V/X

Correct Answer: PFR of volume V ✔

Option A: Equilibrium constant is infinite

Option B: Fractional conversion of ‘A’ at equilibrium is unity

Option C: Concentration of ‘A’ at equilibrium is zero

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: 18

Option B: 24

Option C: 6

Option D: 12

Correct Answer: 24 ✔

Option A: 0.5

Option B: -0.5

Option C: 1

Option D: 1.5

Correct Answer: 0.5 ✔

Option A: Surface Kc/(1 + TS) reaction between absorbed A and B in the gas phase

Option B: Surface reaction between absorbed A and absorbed B

Option C: Surface reaction between A in the gas phase and absorbed B

Option D: Desorption of C

Correct Answer: Desorption of C ✔

Option A: Rate of reaction

Option B: Frequency factor

Option C: Rate constant

Option D: Activation energy

Correct Answer: Rate constant ✔

Option A: Different for reactants and products

Option B: Dimensionless

Option C: Depends on the stoichiometric co-efficient

Option D: All of the above

Correct Answer: All of the above ✔

Option A: 0.253

Option B: 0.338

Option C: 0.152

Option D: 0.637

Correct Answer: 0.338 ✔

Option A: Increases

Option B: Decreases

Option C: Remains unchanged

Option D: Increases exponentially

Correct Answer: Decreases ✔

Option A: CSTR

Option B: CSTR in series

Option C: Plug flow reactor

Option D: Recycle reactor

Correct Answer: Recycle reactor ✔

Option A: Higher

Option B: Much higher

Option C: Lower

Option D: Much lower

Correct Answer: Much lower ✔

Option A: Time of reaction

Option B: Temperature of the system

Option C: Extent of reaction

Option D: Initial concentration of the reactants

Correct Answer: Temperature of the system ✔

Option A: 0

Option B: 500

Option C: 750

Option D: ∞

Correct Answer: 0 ✔

Option A: Improves the activity of a catalyst

Option B: Acts as a catalyst support

Option C: Itself has very high activity

Option D: All A., B. and C.

Correct Answer: Improves the activity of a catalyst ✔

Option A: 1/(time)n

Option B: (Concentration)1 – n/(time)

Option C: (Concentration)n – 1/(time)

Option D: None of these

Correct Answer: B. (Concentration)1 – n/(time) ✔

Option A: Increases

Option B: Decreases

Option C: Decreases exponentially

Option D: Can either increase or decrease; depends on the frequency factor

Correct Answer: Decreases ✔

Option A: Temperature only

Option B: Pressure only

Option C: Temperature and pressure

Option D: Ratio of reactants

Correct Answer: Temperature only ✔

Option A: Activation energies of a reaction

Option B: Reaction mechanism

Option C: Extent of non-ideal flow in the vessel

Option D: None of these

Correct Answer: Extent of non-ideal flow in the vessel ✔

Option A: The rate of disappearance of ‘Y’ is equal to the rate of appearance of ‘Z’

Option B: The rate of disappearance of ‘Y’ is equal to the rate of disappearance of ‘X’

Option C: Three times the rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’

Option D: The rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’

Correct Answer: C. Three times the rate of disappearance of ‘X’ is equal to the rate of appearance of ‘Z’ ✔

Option A: Continuous reaction

Option B: Unreacted core

Option C: Both A. and B.

Option D: Neither A. and B.

Correct Answer: C. Both A. and B. ✔

Option A: 2O3 ⇌ 3O2

Option B: N2 + O2 ⇌ 2NO

Option C: 2NO2 ⇌ N2O4

Option D: 2SO2 + O2 ⇌ 2SO3

Correct Answer: N2 + O2 ⇌ 2NO ✔

Option A: Mixed reactor is always larger than the plug-flow reactor

Option B: Ratio of the volume of the mixed reactor to that of the plug-flow reactor decreases with order

Option C: Reactor size is independent of the type of flow

Option D: Density variation during reaction affects design

Correct Answer: Mixed reactor is always larger than the plug-flow reactor ✔

Option A: 1/2

Option B: 1/3

Option C: 1/9

Option D: 3

Correct Answer: 1/2 ✔

Option A: e-t/η

Option B: e-t/η/η

Option C: 1 – e-t/η

Option D: 1 – (e-t/η/η)

Correct Answer: e-t/η ✔

Option A: Rate constant

Option B: Conversion

Option C: Reaction speed

Option D: Equilibrium constant

Correct Answer: Conversion ✔

Option A: Operating conditions (e.g. pressure and temperature)

Option B: Rate constant

Option C: Density of mixture

Option D: None of these

Correct Answer: Density of mixture ✔

Option A: E

Option B: E + ΔHA

Option C: E + ΔHA – ΔHR)

Option D: ΔHA + ΔHR

Correct Answer: E ✔

Option A: 190

Option B: 290

Option C: 390

Option D: 490

Correct Answer: 290 ✔

Option A: Decreases the activation energy

Option B: Alters the reaction mechanism

Option C: Increases the frequency of collisions of reacting species

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: CA = 1.2 CA0 (1 – X)/(1 – 0.33X)

Option B: CA = 1.2 CA0 (1 – X)/(1 – 0.5X)

Option C: CA = 0.83 CA0 (1 – X)/(1 – 0.33X)

Option D: CA = 0.83 CA0 (1 – X)/(1 – 0.5X)

Correct Answer: C. CA = 0.83 CA0 (1 – X)/(1 – 0.33X) ✔

Option A: The feed rate is measured at temperature and pressure in the reactor

Option B: The temperature, pressure and the density of reaction mixture remains constant throughout the

Option C: There is no change in number of moles in gaseous reaction

Option D: All A., B. and C.

Correct Answer: D. All A., B. and C. ✔

Option A: CA

Option B: CA2

Option C: CA3

Option D: CA4

Correct Answer: CA ✔

Option A: T

Option B: √T

Option C: 1/√T

Option D: T2

Correct Answer: T ✔

Option A: Very slow

Option B: Very fast

Option C: Photochemical

Option D: Both B. and C.

Correct Answer: D. Both B. and C. ✔

Option A: No change

Option B: Increase

Option C: Decrease

Option D: Unpredictable from the data

Correct Answer: No change ✔

Option A: 0

Option B: 0.5

Option C: 1

Option D: 2

Correct Answer: 1 ✔

Option A: Reaction rate

Option B: Rate constant

Option C: Energy of activation

Option D: Frequency factor

Correct Answer: Rate constant ✔

Option A: Temperature

Option B: Pressure

Option C: Reactant’s concentration

Option D: None of these

Correct Answer: Temperature ✔

Option A: 0

Option B: 1

Option C: < 1

Option D: ∞

Correct Answer: ∞ ✔

Option A: Increases the speed of a

Option B: Decreases the speed of a

Option C: Can either increase or decrease the speed of a

Option D: Alters the value of equilibrium constant in a reversible

Correct Answer: Can either increase or decrease the speed of a ✔

Option A: N2

Option B: H2

Option C: CO2

Option D: He

Correct Answer: N2 ✔

Option A: Increases

Option B: Decreases

Option C: Remain unaffected

Option D: Unpredictable from the data

Correct Answer: Remain unaffected ✔

Option A: Strong pore diffusion control and mass transfer not controlling

Option B: Both pore diffusion and mass transfer not controlling

Option C: Both pore diffusion and mass transfer controlling

Option D: Mass transfer controlling

Correct Answer: Strong pore diffusion control and mass transfer not controlling ✔

Option A: d(VCA)/dt = -F (CAF – CA) – kCA2V

Option B: d(VCA)/dt = F (CAF – CA) – kCA2V

Option C: d(VCA)/dt = -FCA – kCA2V

Option D: d(VCA)/dt = FCAF – kCA2V

Correct Answer: D. d(VCA)/dt = FCAF – kCA2V ✔

Option A: Catalyst size is reduced or the catalyst diffusivity is reduced

Option B: Catalyst size is reduced or the catalyst diffusivity is increased

Option C: Catalyst size is increased or the catalyst diffusivity is reduced

Option D: Catalyst size is increased or the catalyst diffusivity is increased

Correct Answer: Catalyst size is reduced or the catalyst diffusivity is increased ✔

Option A: Product yields and quality cannot be achieved in continuous process, because of long

Option B: Sales demand of product is not steady

Option C: Same equipment cannot be used for several processes of the same nature

Option D: All A., B. & C.

Correct Answer: D. All A., B. & C. ✔

Option A: Catalyst

Option B: Temperature

Option C: Reactant’s concentration

Option D: Number of molecules of reactants taking part in the reaction

Correct Answer: Number of molecules of reactants taking part in the reaction ✔

Option A: Water will evaporate

Option B: Equilibrium will not be attained

Option C: More ice will be formed

Option D: More water will be formed

Correct Answer: More water will be formed ✔

Option A: Solid density

Option B: Pore volume

Option C: Surface area

Option D: All A., B. and C.

Correct Answer: Surface area ✔

Option A: More

Option B: Less

Option C: Same

Option D: Either A. or B., depends on order of reaction

Correct Answer: More ✔

Option A: A highly exothermic reaction is to be controlled

Option B: Undesirable side reaction (at high concentration of one of the reactants) is to be avoided

Option C: A gas is to be reacted with liquid (e.g. hydrogenation of fat)

Option D: All A., B., and C.

Correct Answer: All A., B., and C. ✔

Option A: CA0/2K

Option B: CA0/K

Option C: 0.693/K

Option D: 1/K

Correct Answer: CA0/2K ✔

Option A: Film

Option B: Ash layer

Option C: Pore

Option D: None of these

Correct Answer: Film ✔

Option A: Pressure and temperature only

Option B: Temperature and composition only

Option C: Pressure and composition only

Option D: Pressure, temperature and composition

Correct Answer: Pressure, temperature and composition ✔

Option A: Time for half change is half the time taken for completion of the reaction

Option B: Time for half change is independent of the initial concentration

Option C: Time for completion of the reaction is independent of the initial concentration

Option D: Reaction rate is trebled when the initial concentration is trebled

Correct Answer: Time for half change is half the time taken for completion of the reaction ✔

Option A: More

Option B: Less

Option C: Same

Option D: Either A. or B., depends on other factors

Correct Answer: Same ✔

Option A: Linearly

Option B: Exponentially

Option C: Parabolically

Option D: Logarithmically

Correct Answer: Exponentially ✔

Option A: Langmuir’s assumption applies to every adsorbed layer

Option B: There is no dynamic equilibrium between successive layer

Option C: The adsorbed layer may be polymolecular in thickness and the heat of adsorption in each layer

Option D: None of these

Correct Answer: There is no dynamic equilibrium between successive layer ✔

Option A: Sulphur dioxide oxidation

Option B: Ethylene oxidation

Option C: Benzene oxidation

Option D: Ammonia synthesis

Correct Answer: Ethylene oxidation ✔

Option A: Equal in size

Option B: Of different sizes

Option C: Of such size that the ratio of their volumes is < 5

Option D: None of these

Correct Answer: Equal in size ✔

Option A: Gas film

Option B: Ash

Option C: Chemical reaction

Option D: None of these

Correct Answer: Ash ✔

Option A: 0

Option B: 1

Option C: 2

Option D: 3

Correct Answer: 3 ✔

Option A: Initiated by

Option B: Accompanied with emission of

Option C: Catalysed by

Option D: Used to convert heat energy into

Correct Answer: Initiated by ✔

Option A: Protons

Option B: Neutrons

Option C: Electrons

Option D: None of these

Correct Answer: Electrons ✔

Option A: k2 CB0 > k1 CA0

Option B: k CA0 > k2.CB0

Option C: CB0 > CA0

Option D: CA0 > CB0

Correct Answer: k2 CB0 > k1 CA0 ✔

Option A: More than

Option B: Less than

Option C: Same as

Option D: Data insufficient; can’t be predicted

Correct Answer: Same as ✔