Helium-mercury method can be used to determine the _____________ of the catalyst particle?

Related Mcqs:

1. Helium-mercury method is used for the measurement of the ________________ of the catalyst?

   A. Surface area
   B. Porosity
   C. Pore volume
   D. Both B. & C.

2. 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

3. 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

4. B.E.T. method can be used to determine the ___________________ of a porous catalyst?

   A. Solid density
   B. Pore volume
   C. Surface area
   D. All A., B. and C.

5. Following isothermal kinetic data are obtained in a basket type of mixed flow reactor for a porous catalyst. Determine the role of pore diffusion and external mass transfer processes ?

   A. Strong pore diffusion control and mass transfer not controlling
   B. Both pore diffusion and mass transfer not controlling
   C. Both pore diffusion and mass transfer controlling
   D. Mass transfer controlling

6. Effectiveness factor E. of a catalyst pellet is defined as, E = (actual rate within pore of the catalyst)/(rate if not snowed by pore diffusion), Effectiveness factor for a first order reaction is given by (where, T = Thiele modulus) ___________________?

   A. tan hT/T
   B. tan T/T
   C. tan hT/tan T
   D. None of these

7. A catalyst is said to be a negative catalyst, if it ___________________?

   A. Retards the rate of reaction
   B. Reduces the value of equilibrium constant
   C. Does not initiate the reaction
   D. All A., B. and C.

8. _____________ gas is normally employed in B.E.T. method of finding out the surface area of catalyst?

   A. N2
   B. H2
   C. CO2
   D. He

9. If helium is introduced in a reactor containing O2, SO2 and SO3 at equilibrium, so that total pressure increases while volume and temperature remains constant. In this case the dissociation of SO3 (as per Le Chatelier’s principle)?

   A. Decreases
   B. Increases
   C. Remains unaltered
   D. Changes unpredictably

10. B.E.T. method of finding out surface area of a catalyst, uses the extension of _________________ isotherm?

    A. Langmuir
    B. Freundlich
    C. Tempkin
    D. None of these