A. Gas film
B. Ash
C. Chemical reaction
D. None of these
Related Mcqs:
- For the non catalytic reaction of particles with surrounding fluid, the same needed to achieve the same fractional conversion for particles of different unchanging sizes is proportional to the particle diameter, when the ________________ is the controlling resistance?
A. Film diffusion
B. Diffusion through ash layer
C. Chemical reaction
D. Either A., B. or C. - For the non-catalytic reaction of particles with surrounding fluid, the time needed to achieve the same fractional conversion for particles of different but unchanging sizes is proportional to the square of particle diameter, when the _______________ is the controlling resistance?
A. Film diffusion
B. Diffusion through ash layer
C. Chemical reaction
D. Either A., B. or C. - 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
B. Inner catalyst core of radius R/2 does not participate in reaction
C. Inner catalyst core of radius 7R/8 does not participate in reaction
D. Effectiveness factor for a zero order reaction cannot be 7/8 as it must always be 1 - If Thiele modulus is ________________, then the pore diffusion resistance in a catalyst may be considered as negligible?
A. 0
B. ∞
C. < 0.5
D. > 0.5 - Brunauer, Emmet and Teller (BET) equation is used to determine the specific surface area of a porous particle but not the pore volume & the porosity of the catalyst bed. Which of the following postulates is not used to derive BET equation ?
A. Langmuir’s assumption applies to every adsorbed layer
B. There is no dynamic equilibrium between successive layer
C. The adsorbed layer may be polymolecular in thickness and the heat of adsorption in each layer
(except the first one) is involved in each of the evaporation process
D. None of these - Helium-mercury method can be used to determine the _____________ of the catalyst particle?
A. Pore volume
B. Solid density
C. Porosity
D. All A., B., & C. - Participation of _______________ is involved in the occurrence of a chemical reaction?
A. Protons
B. Neutrons
C. Electrons
D. None of these - ______________ catalytic reaction is involved in the thermal cracking of gas oil ?
A. Homogeneous
B. Non-Homogeneous
C. Heterogeneous
D. Non-Heterogeneous - Which of the following resistances is not involved in a gas phase catalytic (gas-solid) reaction ?
A. Ash resistance
B. Gas film and pore surface diffusion resistances for reactants
C. Surface phenomenon resistance
D. Gas film and pore surface diffusion resistances for products - Carbon particles accumulated on the catalyst used in the gas oil cracking lies in the category of _____________________ poison?
A. Deposited
B. Chemisorbed
C. Selectivity
D. Stability
