A. L √(K/D1)
B. 1/[L√(K/D1)]
C. 1
D. ∞
Related Mcqs:
- 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 - Which of the following is not a dimension-less group used in catalysis? (Where, D = dispersion co-efficient, cm2/sec.D1 = diffusion co-efficient; cm2/sec L = length of the reactor, cm t = time, sec, v = volumetric flow rate, cm3/sec. V = volume, cm3.) ?
A. Reactor dispersion number (D/vL)
B. Reduced time (vt/V)
C. Thiele modulus L √(k/D1)
D. None of these - For a first order chemical reaction in a porous catalyst, the Thiele modulus is 10. The effectiveness factor is approximately equal to ____________________?
A. 0
B. 1
C. 0.1
D. 0.5 - For a solid catalysed chemical reaction, the effectiveness of solid catalyst depends upon the ______________ adsorption?
A. Physical
B. Chemical
C. Both A. and B.
D. Neither A. nor B. - For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the____________________?
A. Catalyst size is reduced or the catalyst diffusivity is reduced
B. Catalyst size is reduced or the catalyst diffusivity is increased
C. Catalyst size is increased or the catalyst diffusivity is reduced
D. Catalyst size is increased or the catalyst diffusivity is increased - If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst___________________?
A. Porosity is very important
B. Porosity is of less importance
C. Internal surface area is utilised efficiently
D. None of these - 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 - A reaction which is catalysed by a base is catalysed by all substances which have a tendency to_______________________?
A. Lose a proton
B. Gain a proton
C. Gain an electron
D. None of these - A reaction which is catalysed by an acid is also catalysed by any substance, which has a tendency to _________________?
A. Lose a proton
B. Gain a proton
C. Lose an electron
D. None of these - 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
