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1.	The variation of Chemisorption with Pressure is ____(a) Chemisorption increases with increase in pressure(b) Chemisorption decreases with increase in pressure(c) Chemisorption increases with decrease in pressure(d) Change of pressure has no effect on ChemisorptionI got this question in quiz.I would like to ask this question from Packed Bed Catalytic Reactor topic in chapter Packed Bed Catalytic Reactor, Fluidised Bed and Transport Reactors of Chemical Reaction Engineering
Answer» Correct answer is (d) CHANGE of pressure has no effect on CHEMISORPTION For explanation I WOULD SAY: Chemisorption increases with increase in TEMPERATURE, but change in pressure has no effect. The chemical adsorption is irreversible.

2.	For the reaction step to be the controlling mechanism in a catalytic reversible reaction, which of the following is valid?(a) Rate of adsorption > Rate of desorption(b) Rate of adsorption < Rate of desorption(c) Rate of adsorption = Rate of desorption(d) Rate of adsorption ≠ Rate of desorptionThis question was posed to me during an internship interview.The origin of the question is Packed Bed Catalytic Reactor topic in division Packed Bed Catalytic Reactor, Fluidised Bed and Transport Reactors of Chemical Reaction Engineering
Answer» CORRECT ANSWER is (c) Rate of ADSORPTION = Rate of desorption To elaborate: If rate of adsorption of GAS equals its rate of desorption, the mechanism is in EQUILIBRIUM. Reaction becomes the controlling mechanism.

3.	The Langmuir Hinshelwood mechanism for equimolar reactant feed is ____(a) \(\frac{aP}{(1+bP)^2}\) = -r0(b) \(\frac{P}{(1+bP)^2}\) = -r0(c) \(\frac{aP}{(bP)^2}\)= -r0(d) \(\frac{aP}{(1+bP)}\) = -r0This question was addressed to me in quiz.I want to ask this question from Packed Bed Catalytic Reactor topic in portion Packed Bed Catalytic Reactor, Fluidised Bed and Transport Reactors of Chemical Reaction Engineering
Answer» The correct choice is (a) \(\frac{aP}{(1+bP)^2}\) = -r0 To EXPLAIN I would SAY: A + B → R If \(\frac{A}{B}\)=1, YA = YB = 0.5 for equimolar feed -r0 = \(\frac{kP_A P(0.5)(0.5)}{(1+(0.5k_A P)+(0.5k_B P))^2}\) = \(\frac{aP}{(1+bP)^2}. \) Where, a and b are constants, P is the TOTAL pressure.

4.	State true or false.Physisorption occurs by Van-der-waal’s forces.(a) Physisorption occurs by Van-der-waal’s forces.(b) True(c) FalseThe question was asked during an interview.I'm obligated to ask this question of Packed Bed Catalytic Reactor topic in chapter Packed Bed Catalytic Reactor, Fluidised Bed and Transport Reactors of Chemical Reaction Engineering
Answer» Right answer is (a) Physisorption occurs by Van-der-waal’s FORCES. Explanation: Physical adsorption is due to intermolecular Van-der-waal’s forces. HEAT of adsorption is small and the adsorption is COMPLETE reversible.

5.	The sequence of steps in a heterogeneous catalytic reaction is ____(a) Diffusion → Adsorption → Reaction → Desorption → Diffusion → Mass transfer → Mass transfer(b) Mass transfer → Diffusion → Adsorption → Reaction → Desorption → Diffusion → Mass transfer(c) Mass transfer → Diffusion → Adsorption → Desorption → Diffusion → Mass transfer → Reaction(d) Mass transfer → Adsorption → Diffusion Reaction → Desorption → Diffusion → Mass transferI got this question in a job interview.My question comes from Packed Bed Catalytic Reactor in portion Packed Bed Catalytic Reactor, Fluidised Bed and Transport Reactors of Chemical Reaction Engineering
Answer» The correct answer is (b) Mass TRANSFER → Diffusion → Adsorption → Reaction → DESORPTION → Diffusion → Mass transfer Easiest explanation: The catalytic reaction OCCURS by the mass transfer to the catalytic surface, followed by the diffusion of the reactant gas through the PRODUCT layer. Reaction occurs at the gas – catalyst interface. Diffusion of the product gas occurs through the product layer. Mass transfer of the product gas occurs BACK through the gas film.

6.	Which of the following is not an assumption of Langmuir model?(a) Energy of adsorption of gas molecules to the adsorbent site is different at different adsorbing site(b) Maximum amount of adsorption corresponds to a monolayer(c) Desorption rate depends on the amount of material adsorbed onto the solid surface(d) Gas phase molecules are adsorbed on discrete points on the solid surfaceThe question was asked in a job interview.Asked question is from Packed Bed Catalytic Reactor topic in chapter Packed Bed Catalytic Reactor, Fluidised Bed and Transport Reactors of Chemical Reaction Engineering
Answer» RIGHT answer is (a) Energy of adsorption of gas MOLECULES to the adsorbent site is different at different adsorbing site To ELABORATE: The energy of adsorption is same for all the sites on the adsorbent SURFACE. The adsorption of a gas molecule at one site is INDEPENDENT of the adsorption on an adjacent site.