Rate of a chemical reaction is not affected by the____________________?

Number of molecules of reactants taking part in the reaction

Rate determining step in a reaction consisting of a number of steps in series is the ______________ step?

Data insufficient; can’t be predicted

Promoter_____________________?

Initiates a chemical reaction and is a catalyst by itself

Alters the position of equilibrium in a reversible reaction

Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals

Pick the WRONG design guideline for a reactor in which the reactions, A → R (desired) and A → S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k1/k2). CA a-b ?

Use batch reactor or plug flow reactor, when a > b

Use high pressure and eliminate inerts, when a > b

Use batch reactor or plug flow reactor, when a > b

Use CSTR with a high conversion, when a > b

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

Photochemical reaction rate does not depend significantly on temperature, because____________________?

The energy of reacting molecules exceeds the activation energy by absorption of light

Organic catalysts differ from the inorganic catalyst in the sense that the former is________________?

Active at very high temperature only

Active at cryogenic temperatures only

Active at very high temperature only

On application of pressure to the equilibrium system, ice ⇌ water; which of the following phenomenon will occur ?

Equilibrium will not be attained

Molecularity of a reaction__________________?

Is always equal to the overall order of reaction

May not be equal to the order of reaction

Can’t have a fractional value

Mean residence time is equal to the space time, when_________________?

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

The temperature, pressure and the density of reaction mixture remains constant throughout the reactor

There is no change in number of moles in gaseous reaction

Inversion of cane sugar is an example of ______________________?

Unimolecular reaction with second order

Unimolecular reaction with first order

Bimolecular reaction with second order

Bimolecular reaction with first order

Unimolecular reaction with second order

Integral method for analysing the kinetic data is used _____________________?

For testing specific mechanisms with simple rate expressions

In the reversible reaction of the type, A + B ⇌ AB, in general__________________?

The combination reaction will be endothermic, while the dissociation reaction will be exothermic

Both forward and backward reactions will be exothermic

Neither of the reactions will be endothermic

The combination reaction will be exothermic, while the dissociation reaction will be endothermic

The combination reaction will be endothermic, while the dissociation reaction will be exothermic

In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3), the value of the equilibrium constant depends on the_________________?

Initial concentration of N2 and H2

In the fluid catalytic cracker (FCC), the cracking reaction is _____________ (i) and the regeneration is _______________ (ii) _______________?

(i) exothermic (ii) endothermic

(i) endothermic (ii) endothermic

(i) endothermic (ii) exothermic

In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for________________?

Slow reactions in catalyst of large pore diameter

Fast reactions in catalyst of small pore diameter

Fast reaction in catalyst of large pore diameter

Slow reactions in catalyst of small pore diameter

Slow reactions in catalyst of large pore diameter

In Langmuir treatment of adsorption,_________________?

All the adsorption does not take place by the same mechanism

Whole surface of the catalyst does not have the same activity for adsorption and there is attraction between the adsorbed molecule

Whole surface of the catalyst is essentially uniform and the adsorbed molecule has no effect on the rate of adsorption per site

All the adsorption does not take place by the same mechanism

Extent of adsorption is more than one complete monomolecular layer on the surface

In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is___________________?

Either A. or B., depends on other factors

409 + Mcqs in Chemical Reaction in Chemical Engineering Page 4 McqOptions

151.	Rate of a chemical reaction is not affected by the____________________?
A.	Catalyst
B.	Temperature
C.	Reactant’s concentration
D.	Number of molecules of reactants taking part in the reaction
Answer» E.

Discussion

152.	Rate of a chemical reaction is independent of the concentration of the reactants for a _________________ reaction?
A.	Zero order
B.	Third order
C.	Consecutive
D.	None of these
Answer» B. Third order

Discussion

153.	Rate determining step in a reaction consisting of a number of steps in series is the ______________ step?
A.	Fastest
B.	Slowest
C.	Intermediate
D.	Data insufficient; can’t be predicted
Answer» C. Intermediate

Discussion

154.	Rate constant ‘k’ and absolute temperature ‘T’ are related by collision theory (for bimolecular) as______________________?
A.	k ∝ T1.5
B.	k ∝ exp(-E/RT)
C.	k ∝ √T
D.	k ∝ T
Answer» D. k ∝ T

Discussion

155.	Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants; but it is a function of reaction temperature. In a chemical reaction, the time required to reduce the concentration of reactant from 100 gm moles/litre to 50 gm moles/litre is same as that required to reduce it from 2 gm moles/litre to 1 gm mole/litre in the same volume. Then the order of this reaction is ?
A.	0
B.	1
C.	2
D.	3
Answer» C. 2

Discussion

156.	Radioactive decay follows ______________ order kinetics?
A.	First
B.	Second
C.	Third
D.	Zero
Answer» B. Second

Discussion

157.	Pure ethanol vapor is fed to a reactor packed with alumina catalyst, at the rate of 100 kmole / hr. The reactor products comprise: ethylene: 95 kmole / hr, water vapour: 97.5 k mole / hr and diethyl ether: 2.5 kmole/hr. The reactions occuring can be represented by: C2H5OH → C2H4 + H2O 2C2H5OH → C2H5 – O – C2H5 + H2O The percent conversion of ethanol in the reactor is________________?
A.	100
B.	97.5
C.	95
D.	2.5
Answer» B. 97.5

Discussion

158.	Pure A in gas phase enters a reactor 50% of this A is converted to B through the reaction, A → 3B. Mole fraction of A in the exit stream is______________________?
A.	1/2
B.	1/3
C.	1/4
D.	1/5
Answer» C. 1/4

Discussion

159.	Promoter is added to the catalyst to improve its____________________?
A.	Porosity
B.	Sensitivity
C.	Surface area
D.	None of these
Answer» C. Surface area

Discussion

160.	Promoter_____________________?
A.	Initiates a chemical reaction and is a catalyst by itself
B.	Alters the position of equilibrium in a reversible reaction
C.	Increases the number of active centres by increasing the unevenness of catalyst surface and by creating discontinuities in the crystals
D.	All A., B. and C.
Answer» D. All A., B. and C.

Discussion

161.	Pick the WRONG design guideline for a reactor in which the reactions, A → R (desired) and A → S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k1/k2). CA a-b ?
A.	Use high pressure and eliminate inerts, when a > b
B.	Avoid recycle, when a > b
C.	Use batch reactor or plug flow reactor, when a > b
D.	Use CSTR with a high conversion, when a > b
Answer» C. Use batch reactor or plug flow reactor, when a > b

Discussion

162.	Pick out the wrong statement pertaining to space velocity of flow reactors?
A.	The unit of space velocity is (time)-1
B.	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
C.	The space velocity of 3 hr-1 means that one third reactor volume of feed at specified conditions are being fed into the reactor
D.	None of these
Answer» D. None of these

Discussion

163.	Photochemical reaction rate does not depend significantly on temperature, because____________________?
A.	It is a reversible reaction
B.	It is an exothermic reaction
C.	The energy of reacting molecules exceeds the activation energy by absorption of light
D.	None of these
Answer» D. None of these

Discussion

164.	Photo-chemical reactions occur in presence of ___________________?
A.	Sunlight
B.	Darkness
C.	Solid catalysts
D.	Monochromatic radiation only
Answer» B. Darkness

Discussion

165.	Participation of _______________ is involved in the occurrence of a chemical reaction?
A.	Protons
B.	Neutrons
C.	Electrons
D.	None of these
Answer» D. None of these

Discussion

166.	Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually ________________ the concentration of catalyst, if it does not entail a chain mechanism?
A.	Proportional to
B.	Independent of
C.	Inversely proportional to
D.	Proportional to the square of
Answer» B. Independent of

Discussion

167.	Organic catalysts differ from the inorganic catalyst in the sense that the former is________________?
A.	Active at cryogenic temperatures only
B.	Prohibitively costly
C.	Proteinous in nature
D.	Active at very high temperature only
Answer» D. Active at very high temperature only

Discussion

168.	On application of pressure to the equilibrium system, ice ⇌ water; which of the following phenomenon will occur ?
A.	Water will evaporate
B.	Equilibrium will not be attained
C.	More ice will be formed
D.	More water will be formed
Answer» E.

Discussion

169.	Oil is hydrogenated using nickel catalyst in a __________________ reactor?
A.	Batch
B.	Slurry
C.	Fluidised bed
D.	Fixed bed
Answer» C. Fluidised bed

Discussion

170.	Non-catalytic fluid-solid reactions are represented by _______________ model?
A.	Continuous reaction
B.	Unreacted core
C.	Both A. and B.
D.	Neither A. and B.
Answer» D. Neither A. and B.

Discussion

171.	‘N’ plug flow reactors in series with a total volume ‘V’ gives the same conversion as a single plug flow reactor of volume ‘V’ for _______________ order reactions?
A.	First
B.	Second
C.	Third
D.	Any
Answer» E.

Discussion

172.	‘n’ number of plug flow reactors (P.F.R) in series with a total volume ‘V’ gives the same conversion as one P.F.R. of volume________________?
A.	V/n
B.	V
C.	V.n
D.	1/V
Answer» C. V.n

Discussion

173.	Most important characteristics of gas-liquid reactors are the________________?
A.	Specific inter-facial area
B.	Liquid hold-up
C.	Both A. and B.
D.	None of these
Answer» D. None of these

Discussion

174.	Molecularity of an elementary reaction, P + Q → R + S is ____________________?
A.	1
B.	2
C.	3
D.	4
Answer» E.

Discussion

175.	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.
Answer» E.

Discussion

176.	Mean residence time is equal to the space time, when_________________?
A.	The feed rate is measured at temperature and pressure in the reactor
B.	The temperature, pressure and the density of reaction mixture remains constant throughout the reactor
C.	There is no change in number of moles in gaseous reaction
D.	All A., B. and C.
Answer» E.

Discussion

177.	Maximum equilibrium conversion for endothermic reaction is obtained at the ______________ temperature?
A.	Highest possible
B.	Lowest possible
C.	Intermediate
D.	Room
Answer» B. Lowest possible

Discussion

178.	Limiting reactant in a chemical reaction decides the____________________?
A.	Rate constant
B.	Conversion
C.	Reaction speed
D.	Equilibrium constant
Answer» C. Reaction speed

Discussion

179.	Knudsen diffusion is directly proportional to _____________________?
A.	T
B.	√T
C.	1/√T
D.	T2
Answer» C. 1/√T

Discussion

180.	Kinetics of a solid catalysed reaction can best be studied in a _________________ reactor?
A.	Batch
B.	Plug-flow
C.	Mixed
D.	None of these
Answer» D. None of these

Discussion

181.	Kinetics of a catalytic reaction can be best studied on a/an ______________ reactor?
A.	Mixed
B.	Integral (plug flow)
C.	Differential (flow)
D.	Either A., B. and C.
Answer» E.

Discussion

182.	______________ is the response curve for a step input signal from a reactor ?
A.	S-curve
B.	C-curve
C.	I-curve
D.	None of these
Answer» C. I-curve

Discussion

183.	____________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction ?
A.	Gas film diffusion
B.	Ash diffusion
C.	Chemical reaction
D.	None of these
Answer» D. None of these

Discussion

184.	Ionic reactions occur in____________________?
A.	Solid state only
B.	Liquid state only
C.	Solutions
D.	Any state
Answer» D. Any state

Discussion

185.	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
Answer» D. Unimolecular reaction with second order

Discussion

186.	Integral method for analysing the kinetic data is used _____________________?
A.	When the data are scattered
B.	For testing specific mechanisms with simple rate expressions
C.	Both A. and B.
D.	None of these
Answer» D. None of these

Discussion

187.	In which of the following reactions, the equilibrium will shift to the right, if the total pressure is increased ?
A.	H2 + Cl2 ⇌ 2HCl
B.	N2 + O2 ⇌ 2NO
C.	N2O4 ⇌ 2 NO2
D.	H2 + I2 ⇌ 2HI
Answer» C. N2O4 ⇌ 2 NO2

Discussion

188.	In which of the following gaseous phase reversible reactions, the product yield cannot be increased by the application of high pressure ?
A.	N2 + O2 ⇌ 2NO
B.	PCl3 + Cl2 ⇌ PCl5
C.	N + 3H2 ⇌ 2NH3
D.	2SO2 + O2 ⇌ 2SO3
Answer» B. PCl3 + Cl2 ⇌ PCl5

Discussion

189.	In which of the following gaseous phase reactions, the equilibrium of the reaction remains unaffected by pressure changes ?
A.	2O3 ⇌ 3O2
B.	N2 + O2 ⇌ 2NO
C.	2NO2 ⇌ N2O4
D.	2SO2 + O2 ⇌ 2SO3
Answer» C. 2NO2 ⇌ N2O4

Discussion

190.	In the reversible reaction of the type, A + B ⇌ AB, in general__________________?
A.	Both forward and backward reactions will be exothermic
B.	Neither of the reactions will be endothermic
C.	The combination reaction will be exothermic, while the dissociation reaction will be endothermic
D.	The combination reaction will be endothermic, while the dissociation reaction will be exothermic
Answer» D. The combination reaction will be endothermic, while the dissociation reaction will be exothermic

Discussion

191.	In the hydrodealkylation of toluene to benzene, the following reactions occur: C7H8 + H2 → C6H6 + CH4 2C6H6 ⇌ C12H10 + H2 Toluene and hydrogen are fed to a reactor in a molar ratio 1:5.80% of the toluene gets converted and the selectivity of benzene(defined as moles of benzene formed/moles of toluene converted) is 90%. The fractional conversion of hydrogen is_______________________?
A.	0.16
B.	0.144
C.	0.152
D.	0.136
Answer» C. 0.152

Discussion

192.	In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3), the value of the equilibrium constant depends on the_________________?
A.	Total pressure of the system
B.	Volume of the reactor
C.	Temperature
D.	Initial concentration of N2 and H2
Answer» D. Initial concentration of N2 and H2

Discussion

193.	In the fluid catalytic cracker (FCC), the cracking reaction is _____________ (i) and the regeneration is _______________ (ii) _______________?
A.	(i) exothermic (ii) endothermic
B.	(i) exothermic (ii) exothermic
C.	(i) endothermic (ii) endothermic
D.	(i) endothermic (ii) exothermic
Answer» E.

Discussion

194.	In the converter of the contact process for the manufacture of H2SO4 the equilibrium conversion of SO2__________ (i) __________ with increase in temperature and __________ (ii) __________ with increase in the mole ratio of SO2 to air?
A.	(i) increases (ii) decreases
B.	(i) decreases (ii) increases
C.	(i) increases (ii) increases
D.	(i) decreases (ii) decreases
Answer» C. (i) increases (ii) increases

Discussion

195.	In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for________________?
A.	Fast reactions in catalyst of small pore diameter
B.	Fast reaction in catalyst of large pore diameter
C.	Slow reactions in catalyst of small pore diameter
D.	Slow reactions in catalyst of large pore diameter
Answer» D. Slow reactions in catalyst of large pore diameter

Discussion

196.	In Langmuir treatment of adsorption,_________________?
A.	Whole surface of the catalyst does not have the same activity for adsorption and there is attraction between the adsorbed molecule
B.	Whole surface of the catalyst is essentially uniform and the adsorbed molecule has no effect on the rate of adsorption per site
C.	All the adsorption does not take place by the same mechanism
D.	Extent of adsorption is more than one complete monomolecular layer on the surface
Answer» C. All the adsorption does not take place by the same mechanism

Discussion

197.	In flow reactors, the performance equations interrelate the rate of reaction to the___________________?
A.	Feed rate
B.	Reactor volume
C.	Extent of reaction
D.	All A., B. and C.
Answer» E.

Discussion

198.	In chamber process of sulphuric acid manufacture in industry, the gas phase oxidation of SO2 to SO3 is accomplished by a ______________ reaction ?
A.	Non-catalytic homogeneous
B.	Non-catalytic heterogeneous
C.	Catalytic homogenous
D.	Catalytic heterogeneous
Answer» D. Catalytic heterogeneous

Discussion

199.	In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is___________________?
A.	More
B.	Less
C.	Same
D.	Either A. or B., depends on other factors
Answer» D. Either A. or B., depends on other factors

Discussion

200.	In case of _____________ reactions, the reaction rate does not decrease appreciably as the reaction proceeds?
A.	Catalytic
B.	Parallel
C.	Series
D.	Auto catalytic
Answer» E.

Discussion

Explore topic-wise MCQs in Chemical Engineering.

Rate of a chemical reaction is not affected by the____________________?

Rate of a chemical reaction is independent of the concentration of the reactants for a _________________ reaction?

Rate determining step in a reaction consisting of a number of steps in series is the ______________ step?

Rate constant ‘k’ and absolute temperature ‘T’ are related by collision theory (for bimolecular) as______________________?

Radioactive decay follows ______________ order kinetics?

Pure A in gas phase enters a reactor 50% of this A is converted to B through the reaction, A → 3B. Mole fraction of A in the exit stream is______________________?

Promoter is added to the catalyst to improve its____________________?

Promoter_____________________?

Pick the WRONG design guideline for a reactor in which the reactions, A → R (desired) and A → S (undesired) are to take place. The ratio of the reaction rates is rR/rS = (k1/k2). CA a-b ?

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

Photochemical reaction rate does not depend significantly on temperature, because____________________?

Photo-chemical reactions occur in presence of ___________________?

Participation of _______________ is involved in the occurrence of a chemical reaction?

Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually ________________ the concentration of catalyst, if it does not entail a chain mechanism?

Organic catalysts differ from the inorganic catalyst in the sense that the former is________________?

On application of pressure to the equilibrium system, ice ⇌ water; which of the following phenomenon will occur ?

Oil is hydrogenated using nickel catalyst in a __________________ reactor?

Non-catalytic fluid-solid reactions are represented by _______________ model?

‘N’ plug flow reactors in series with a total volume ‘V’ gives the same conversion as a single plug flow reactor of volume ‘V’ for _______________ order reactions?

‘n’ number of plug flow reactors (P.F.R) in series with a total volume ‘V’ gives the same conversion as one P.F.R. of volume________________?

Most important characteristics of gas-liquid reactors are the________________?

Molecularity of an elementary reaction, P + Q → R + S is ____________________?

Molecularity of a reaction__________________?

Mean residence time is equal to the space time, when_________________?

Maximum equilibrium conversion for endothermic reaction is obtained at the ______________ temperature?

Limiting reactant in a chemical reaction decides the____________________?

Knudsen diffusion is directly proportional to _____________________?

Kinetics of a solid catalysed reaction can best be studied in a _________________ reactor?

Kinetics of a catalytic reaction can be best studied on a/an ______________ reactor?

______________ is the response curve for a step input signal from a reactor ?

____________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction ?

Ionic reactions occur in____________________?

Inversion of cane sugar is an example of ______________________?

Integral method for analysing the kinetic data is used _____________________?

In which of the following reactions, the equilibrium will shift to the right, if the total pressure is increased ?

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

In which of the following gaseous phase reactions, the equilibrium of the reaction remains unaffected by pressure changes ?

In the reversible reaction of the type, A + B ⇌ AB, in general__________________?

In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3), the value of the equilibrium constant depends on the_________________?

In the fluid catalytic cracker (FCC), the cracking reaction is _____________ (i) and the regeneration is _______________ (ii) _______________?

In the converter of the contact process for the manufacture of H2SO4 the equilibrium conversion of SO2__________ (i) __________ with increase in temperature and __________ (ii) __________ with increase in the mole ratio of SO2 to air?

In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for________________?

In Langmuir treatment of adsorption,_________________?

In flow reactors, the performance equations interrelate the rate of reaction to the___________________?

In chamber process of sulphuric acid manufacture in industry, the gas phase oxidation of SO2 to SO3 is accomplished by a ______________ reaction ?

In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is___________________?

In case of _____________ reactions, the reaction rate does not decrease appreciably as the reaction proceeds?

In the fluid catalytic cracker (FCC), the cracking reaction is _____ (i) and the regeneration is _ (ii) _________?

In the converter of the contact process for the manufacture of H2SO4 the equilibrium conversion of SO2 (i) with increase in temperature and (ii) with increase in the mole ratio of SO2 to air?