Chemical Reaction MCQs

Option A: Batch

Option B: Slurry

Option C: Fluidised bed

Option D: Fixed bed

Correct Answer: Slurry ✔

Option A: Biochemical

Option B: Photochemical

Option C: Catalytic

Option D: Autocatalytic

Correct Answer: Autocatalytic ✔

Option A: Combustion of sulphur

Option B: Gasification of carbon

Option C: Thermal cracking of fuel oil

Option D: Steam reforming of naphtha

Correct Answer: Combustion of sulphur ✔

Option A: For testing complicated mechanisms

Option B: When the data are scattered

Option C: When rate expressions are very simple

Option D: None of these

Correct Answer: For testing complicated mechanisms ✔

Option A: Time

Option B: Length

Option C: Diameter

Option D: None of these

Correct Answer: Length ✔

Option A: Non-catalytic homogeneous

Option B: Non-catalytic heterogeneous

Option C: Catalytic homogenous

Option D: Catalytic heterogeneous

Correct Answer: Catalytic homogenous ✔

Option A: Equilibrium constant

Option B: Activation energy

Option C: Heat of formation of the product

Option D: Heat of reaction

Correct Answer: Activation energy ✔

Option A: η and θ are always equal

Option B: η = θ, when the fluid density changes in the reactor

Option C: η = θ, for an isothermic tubular reactor in which the density of the process fluid is constant

Option D: η = θ, for a non-isothermal reactor

Correct Answer: η = θ, for an isothermic tubular reactor in which the density of the process fluid is constant ✔

Option A: Batch

Option B: Plug-flow

Option C: Mixed

Option D: None of these

Correct Answer: Mixed ✔

Option A: 1/(time)(concentration)n – 1

Option B: (Time)-1 (concentration)n – 1

Option C: (Time)n – 1 (concentration)

Option D: None of these

Correct Answer: A. 1/(time)(concentration)n – 1 ✔

Option A: Normally tends to increase the reaction rate

Option B: Does not affect a catalysed reaction

Option C: Does not affect photo-chemical reaction rates

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

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

Option A: Specific surface of a porous catalyst

Option B: Pore size distribution

Option C: Pore diameter

Option D: Porosity of the catalyst bed

Correct Answer: Specific surface of a porous catalyst ✔

Option A: Pore diffusion

Option B: Gas film

Option C: Chemical reaction

Option D: None of these

Correct Answer: Pore diffusion ✔

Option A: (i) exothermic (ii) endothermic

Option B: (i) exothermic (ii) exothermic

Option C: (i) endothermic (ii) endothermic

Option D: (i) endothermic (ii) exothermic

Correct Answer: (i) endothermic (ii) exothermic ✔

Option A: 0.33

Option B: 0.5

Option C: 1

Option D: Data insufficient, can’t be predicted

Correct Answer: 1 ✔

Option A: H2 + Cl2 ⇌ 2HCl

Option B: N2 + O2 ⇌ 2NO

Option C: N2O4 ⇌ 2 NO2

Option D: H2 + I2 ⇌ 2HI

Correct Answer: N2 + O2 ⇌ 2NO ✔

Option A: High capacity

Option B: Presence of axial mixing

Option C: Presence of lateral mixing

Option D: Constant composition and temperature of reaction mixture

Correct Answer: Presence of lateral mixing ✔

Option A: 4

Option B: 16

Option C: 8

Option D: 2

Correct Answer: 16 ✔

Option A: Reaction rate

Option B: Concentration

Option C: Both A. & B.

Option D: Neither A. nor B.

Correct Answer: D. Neither A. nor B. ✔

Option A: Invertase

Option B: Maltase

Option C: Diastase

Option D: Zymase

Correct Answer: Zymase ✔

Option A: Initial concentration of reactants

Option B: Time of reaction

Option C: Temperature of the system

Option D: Extent of reaction

Correct Answer: Temperature of the system ✔

Option A: 0

Option B: 1

Option C: 1.5

Option D: 2

Correct Answer: 0 ✔

Option A: Non-isothermal gas reaction

Option B: Variable fluid density systems

Option C: Constant fluid density systems

Option D: Gas reactions with changing number of moles

Correct Answer: Constant fluid density systems ✔

Option A: Increase of reaction time

Option B: Increase in initial concentration

Option C: Total pressure

Option D: Decrease in total pressure

Correct Answer: Increase of reaction time ✔

Option A: Jacketed liquid phase CSTR

Option B: Jacketed steam heated multitubular reactor

Option C: Multitubular reactor with cooling

Option D: Multistage multitubular reactor with interstage cooling

Correct Answer: Jacketed liquid phase CSTR ✔

Option A: 2/3

Option B: 5/8

Option C: 1/3

Option D: 3/8

Correct Answer: 5/8 ✔

Option A: Temperature should be high in the beginning and decreased towards the end of the reaction

Option B: Very low temperature should be used throughout the reaction

Option C: Very high temperature should be used throughout the reaction

Option D: None of these

Correct Answer: Temperature should be high in the beginning and decreased towards the end of the reaction ✔

Option A: Zero

Option B: First

Option C: Second

Option D: Third

Correct Answer: First ✔

Option A: Decreases

Option B: Increases

Option C: Remain constant

Option D: Become infinite

Correct Answer: Increases ✔

Option A: Lose a proton

Option B: Gain a proton

Option C: Gain an electron

Option D: None of these

Correct Answer: Gain a proton ✔

Option A: Not feasible

Option B: Just feasible

Option C: Very much feasible

Option D: Unpredictable as ΔG is no measure of feasibility of a reaction

Correct Answer: Very much feasible ✔

Option A: Homogeneous

Option B: Non-Homogeneous

Option C: Heterogeneous

Option D: Non-Heterogeneous

Correct Answer: Homogeneous ✔

Option A: (1/η) exp (-t/η)

Option B: η exp (-t/η)

Option C: exp (-t/η)

Option D: (1/η) (-t/η)

Correct Answer: exp (-t/η) ✔

Option A: Moles for med/(surface of catalyst) (time)

Option B: Moles formed/volume of reactor) (time)

Option C: Mole formed/volume of catalyst) (time)

Option D: None of these

Correct Answer: None of these ✔

Option A: Zero order

Option B: Third order

Option C: Consecutive

Option D: None of these

Correct Answer: Zero order ✔

Option A: Poor product quality control

Option B: High labour and handling cost

Option C: High shutdown time requirement for emptying, cleaning and refilling

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

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

Option A: Lessens its selectivity

Option B: May be useful for suppressing undesirable side reactions

Option C: Is added in small quantity during the catalyst manufacture itself

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

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

Option A: CaO is not dissociated

Option B: CO2 escapes continuously

Option C: Of high calcination temperature

Option D: CaO is more stable than CaCO3

Correct Answer: CO2 escapes continuously ✔

Option A: Langmuir adsorption isotherm

Option B: Adsorption isobar

Option C: Freundlich adsorption isotherm

Option D: None of these

Correct Answer: Adsorption isobar ✔

Option A: Porosity

Option B: Sensitivity

Option C: Surface area

Option D: None of these

Correct Answer: Sensitivity ✔

Option A: Constant residence time

Option B: Variation in extent of reaction and properties of the reaction mixture with time

Option C: Variation in reactor volume

Option D: Very low conversion

Correct Answer: Variation in extent of reaction and properties of the reaction mixture with time ✔

Option A: k. t = ln a/(a – x)

Option B: k. t = x/a (a – x)

Option C: k. t = ln (a – x)/a

Option D: k. t = ln a (a – x)/x

Correct Answer: A. k. t = ln a/(a – x) ✔

Option A: 1/3

Option B: 1/2

Option C: 2/3

Option D: 2

Correct Answer: 2/3 ✔

Option A: CA0 = CB0

Option B: CA0 > CB0

Option C: CB0 > CA0

Option D: CB0 ≥ CB0

Correct Answer: CB0 ≥ CB0 ✔

Option A: 1/2

Option B: 1/3

Option C: 1/4

Option D: 1/5

Correct Answer: 1/3 ✔

Option A: Less than

Option B: Equal to

Option C: More than

Option D: Equal to or more than

Correct Answer: Equal to ✔

Option A: Film diffusion

Option B: Diffusion through ash layer

Option C: Chemical reaction

Option D: Either A., B. or C.

Correct Answer: Diffusion through ash layer ✔

Option A: keff = k + kg

Option B: keff = (k+ kg)/2

Option C: keff = (kkg)1/2

Option D: 1/keff = 1/k + 1/kg

Correct Answer: 1/keff = 1/k + 1/kg ✔

Option A: K1 . CX

Option B: (K1 + K2 + K3) CX

Option C: (K1 + K2) CX

Option D: (K2 + K3) CX

Correct Answer: (K1 + K2) CX ✔

Option A: 15, 10, 5

Option B: 5, 10, 15

Option C: 10, 5, 15

Option D: 10, 15, 5

Correct Answer: 15, 10, 5 ✔

Option A: 103.01

Option B: 10-0.67

Option C: 10-3.01

Option D: 100.67

Correct Answer: 100.67 ✔

Option A: Reactor dispersion number (D/vL)

Option B: Reduced time (vt/V)

Option C: Thiele modulus L √(k/D1)

Option D: None of these

Correct Answer: None of these ✔

Option A: XA Vs . η

Option B: XA Vs ln η

Option C: XA/(1 – XA)Vs η

Option D: XA(1 – XA)Vs η

Correct Answer: XA Vs . η ✔

Option A: 0.4

Option B: 0.1

Option C: 0.2

Option D: None of these

Correct Answer: 0.4 ✔

Option A: At the inlet

Option B: At the outlet

Option C: In the reactor

Option D: Averaged over the inlet and outlet

Correct Answer: At the outlet ✔

Option A: 1

Option B: 2

Option C: 3

Option D: 4

Correct Answer: 4 ✔

Option A: 0

Option B: 1

Option C: ∞

Option D: √2π

Correct Answer: 1 ✔

Option A: tan hT/T

Option B: tan T/T

Option C: tan hT/tan T

Option D: None of these

Correct Answer: tan hT/T ✔

Option A: Sunlight

Option B: Darkness

Option C: Solid catalysts

Option D: Monochromatic radiation only

Correct Answer: Sunlight ✔

Option A: 0.875

Option B: 0.5

Option C: 0.425

Option D: Data insufficient to calculate

Correct Answer: 0.875 ✔

Option A: Depends on the pressure only

Option B: Depends on the mechanism of reaction only

Option C: Depends on both pressure and mechanism of reaction

Option D: Is independent of the mechanism of reaction

Correct Answer: Is independent of the mechanism of reaction ✔

Option A: Describes the extensive operating characteristics of a tubular flow reactor

Option B: Is the maximum feed rate per unit volume of reactor for a given conversion

Option C: Is a measure of the ease of the reaction

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

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

Option A: Less than

Option B: Equal to

Option C: More than

Option D: Equal to or more than

Correct Answer: Equal to ✔

Option A: Zero

Option B: First

Option C: Second

Option D: Fractional

Correct Answer: Zero ✔

Option A: 60

Option B: 75

Option C: 90

Option D: 100

Correct Answer: 75 ✔

Option A: Single stirred tank (v = 5 litres)

Option B: Two stirred tank (each of 2.5 litres) in series

Option C: Stirred tank followed by tubular flow reactor (each of 2.5 litres)

Option D: Single tubular flow reactor (v = 5 litres)

Correct Answer: Single tubular flow reactor (v = 5 litres) ✔

Option A: L √(K/D1)

Option B: 1/[L√(K/D1)]

Option C: 1

Option D: ∞

Correct Answer: 1/[L√(K/D1)] ✔

Option A: Combustion of coal particles

Option B: Roasting of sulphide ores

Option C: Manufacture of carbon disulphide from elements

Option D: None of these

Correct Answer: Roasting of sulphide ores ✔

Option A: 1.0 to 10-8

Option B: 1.1 to 102

Option C: 0.1 to 0.9

Option D: None of these

Correct Answer: 1.0 to 10-8 ✔

Option A: k/2

Option B: ln k/2

Option C: ln 2/k

Option D: ln 0.5/k

Correct Answer: ln 2/k ✔

Option A: More uniform operating conditions

Option B: Permits operation at the optimum temperature for a long reaction time

Option C: Higher overall selectivity for a first order consecutive reaction

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

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

Option A: Plot of – rA Vs CA is a straight line with slope k

Option B: Plot of – rA Vs CA is a hyperbola

Option C: Rate of disappearance of reactant A is maximum, where CA = CB

Option D: Both B & C

Correct Answer: Both B & C ✔

Option A: Plug flow

Option B: Dispersion

Option C: Mixed flow

Option D: Tank in series

Correct Answer: Dispersion ✔

Option A: dXA/dt = k1 (1 – XA)2 (1 + 2XA)

Option B: dXA/dt = k1 (1 – XA) (1 + 0.5XA)

Option C: dXA/dt = k1 (1 – XA)

Option D: dXA/dt = k1 (1 – XA)/(1 + XA)

Correct Answer: C. dXA/dt = k1 (1 – XA) ✔

Option A: 100

Option B: 150

Option C: 200

Option D: 225

Correct Answer: 100 ✔

Option A: Be more in CSTR than in PFR

Option B: Be more in PFR than in CSTR

Option C: Be same in both cases

Option D: Depend on the temperature

Correct Answer: Be more in PFR than in CSTR ✔

Option A: A Dirac delta function

Option B: A step function

Option C: A ramp function

Option D: None of the above

Correct Answer: None of the above ✔

Option A: May be lateral mixing of fluid

Option B: Should not be any mixing along the flow path

Option C: Both A. and B.

Option D: Neither A. nor B.

Correct Answer: C. Both A. and B. ✔

Option A: 0

Option B: 1

Option C: 2

Option D: 3

Correct Answer: 2 ✔

Option A: Temperature and pressure only

Option B: Temperature and composition only

Option C: Pressure and composition only

Option D: All temperature, pressure and composition

Correct Answer: All temperature, pressure and composition ✔

Option A: Is always greater for plug-flow reactor than for the single CSTR of the same volume

Option B: Statement in A. is wrong

Option C: Decreases with increasing conversion

Option D: Both A. and C. hold good

Correct Answer: D. Both A. and C. hold good ✔

Option A: One of the reactants acts as a catalyst

Option B: One of the products acts as a catalyst

Option C: Catalysts have very high selectivity

Option D: No catalyst is used

Correct Answer: One of the products acts as a catalyst ✔

Option A: 0

Option B: > 150

Option C: ∞

Option D: < 2100

Correct Answer: ∞ ✔

Option A: Pressure

Option B: Temperature

Option C: Concentration and catalyst

Option D: None of these

Correct Answer: Concentration and catalyst ✔

Option A: 1

Option B: > 1

Option C: ∞

Option D: ≥ 1

Correct Answer: ∞ ✔

Option A: Is same as heat of reaction at constant pressure

Option B: Is the minimum energy which the molecules must have before the reaction can take place

Option C: Varies as fifth power of the temperature

Option D: Both B. and C.

Correct Answer: Is the minimum energy which the molecules must have before the reaction can take place ✔

Option A: Porosity is very important

Option B: Porosity is of less importance

Option C: Internal surface area is utilised efficiently

Option D: None of these

Correct Answer: Porosity is of less importance ✔

Option A: Higher in P.F. reactor

Option B: Higher in CSTR

Option C: Same in both the reactors

Option D: Data insufficient; can’t be predicted

Correct Answer: Higher in P.F. reactor ✔

Option A: Usually equal to the residence time

Option B: The reciprocal of the space velocity

Option C: A measure of its capacity

Option D: Both A. and B.

Correct Answer: D. Both A. and B. ✔

Option A: Autocatalytic

Option B: Exothermic

Option C: Endothermic

Option D: Autothermal

Correct Answer: Autocatalytic ✔

Option A: An experimentally determined quantity

Option B: Always equal to the total stoichiometric number of reactants

Option C: Never fractional

Option D: None of these

Correct Answer: An experimentally determined quantity ✔

Option A: Increased temperature reduces the activation energy

Option B: Fraction of molecules having threshold energy increases

Option C: Collision frequency increases

Option D: Value of threshold energy decreases

Correct Answer: Fraction of molecules having threshold energy increases ✔

Option A: The composition of reactants remains constant along a flow path

Option B: The conversion of the reactant varies from point to point along a flow path

Option C: There is no lateral mixing of fluid

Option D: There may be diffusion along the flow path

Correct Answer: The conversion of the reactant varies from point to point along a flow path ✔

Option A: Initiates a chemical reaction and is a catalyst by itself

Option B: Alters the position of equilibrium in a reversible reaction

Option C: Increases the number of active centres by increasing the unevenness of catalyst surface and by

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

Correct Answer: C. Increases the number of active centres by increasing the unevenness of catalyst surface and by
creating discontinuities in the crystals ✔

Option A: 0.16

Option B: 0.144

Option C: 0.152

Option D: 0.136

Correct Answer: 0.144 ✔

Option A: Slurry

Option B: Plug flow

Option C: Homogeneous catalytic

Option D: None of these

Correct Answer: Slurry ✔

Option A: Langmuir

Option B: Freundlich

Option C: Tempkin

Option D: None of these

Correct Answer: Langmuir ✔

Option A: First

Option B: Zero

Option C: Second

Option D: Third

Correct Answer: Second ✔

Option A: V/n

Option B: V

Option C: V.n

Option D: 1/V

Correct Answer: V ✔

Option A: Linearly with time

Option B: Exponentially with time

Option C: Very abruptly towards the end of the reaction

Option D: Logarithmically with time

Correct Answer: Exponentially with time ✔