141. In which of the following gaseous phase reactions, the equilibrium of the reaction remains unaffacted by pressure changes ?
2O? ? 3O?
N? + O? ? 2NO
2NO? ? N?O?
2SO? + O? ? 2SO?
✅ The correct answer is option B.
Chemical Reaction Engineering MCQs
142. What is the unit of the rate constant in a chemical reaction in which 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on?
Litre/mole.second
Moles/litre.second
Litre/mole
Litre/second
✅ The correct answer is option A.
143. Signal normally used to study non-ideal flow by stimulus response technique is __________ input.
Pulse
Step
Both A & B
Neither A nor B
✅ The correct answer is option C.
144. A batch adiabatic reactor at an initial temperature of 373°K is being used for the reaction, A → B. Assume the heat of reaction is – 1kJ/mole at 373°K and heat capacity of both A and B to be constant and equal to 50J/mole.K. The temperature rise after a conversion of 0.5 will be
5°C
10°C
20°C
100°C
✅ The correct answer is option B.
145. The rate expression for a heterogenous catalytic reaction is given by, – rA = K.KA PA(1 + KA.PA + Kr.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR >> (1 + KA PA), the apparent activation energy EA is equal to (given E is the activation energy for the reaction and ΔHR and ΔHA are the activation energies of adsorption of R and A)
E
E + ΔHA
E + ΔHA – ΔHR
ΔHA + ΔHR
✅ The correct answer is option C.
146. “A spherical porous catalyst particle of radius R is subjected to reactant A which reacts to form B by a zero order surface reaction A → B. Film mass transfer resistance is negligible and pore diffusion of A is rate controlling. The effectiveness factor of the catalyst is reported as 7/8. Which of the following statement is true?A. Inner catalyst core of radius R/8 does not participate in reaction.”
Inner catalyst core of radius R/8 does not participate in reaction
Inner catalyst core of radius R/2 does not participate in reaction
Inner catalyst core of radius 7R/8 does not participate in reaction
Ffectiveness factor for a zero order reaction can not be 7/8 as it must always be 1
✅ The correct answer is option A.
147. ‘Unreacted core model’ represents the reaction involving
Combustion of coal particles
Roasting of sulphide ores
Manufacture of carbon disulphide from elements
None of these
✅ The correct answer is option B.
148. During manufacture of H₂SO₄, the oxidation of SO₂ to SO₃ by oxygen is an en- dothermic reaction. The yield of SO₃ will be maximised, if the
Temperature is increased
Pressure is reduced
Temperature is increased and pressure is reduced
Temperature is reduced and pressure is increased
✅ The correct answer is option D.
149. According to Arhenious equation of temperature dependency of rate constant for an elementary reaction
K ∝ √T
K ∝ e-E/RT
K ∝ T e-E/RT
None of these
✅ The correct answer is option B.
150. The value of steric factor ‘P’ in the equation k = PZeE/RT usually ranges from
L.0 to 10⁻⁸
L.l.to 10²
0.1 to 0.9
None of these
✅ The correct answer is option A.