Related Questions

Effectiveness factor (E) of a catalyst pellet is defined as, E = (actual rate within pore of catalyst/rate if notsnowed 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
If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the
A Pressure
B Temperature
C Both A & B
D Neither A nor B
If Thiele modulus is __________ , then the pore diffusion resistance in a catalyst may be considered as negligible.
A 0
B ∞
C > 0.5
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
For the hydrogenation of oils (i) __________ is commonly used as catalyst and (ii) __________ is a catalyst poison.
A (i) platinum (ii) sulphur
B (i) palladium (ii) oxygen
C (i) nickel (ii) sulphur
D (i) nickel (ii) oxygen
Ordinary diffusion process is also called __________ diffusion.
A Pressure
B Thermal
C Concentration
D Forced
A catalyst is said to be a negative catalyst, ifit
A Retards the rate of reaction
B Reduces the value of equilibrium constant
C Does not initiate the reaction
D All of the above
The bulk modulus of elasticity with increase in pressure
A Increases
B Decreases
C Remain constant
D Increases first up to certain limit and then decreases
The importance of diffusion in a catalyst are increased by
A Large catalyst particle size
B An active surface of the catalyst
C Small pore diameter
D All of the above
Simple diffusion and facilitated diffusion share the following characteristics
A Do not require ATP
B Saturation kinetics
C Transport solute along concentration gradient
D Can be blocked by specific inhibitors
E Require transport protein

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