If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst

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

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

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 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

If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion.

A

Film

B

Ash layer

C

Pore

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

Bulk diffusion in catalyst pore __________ with increase in pressure.

A

Increases

B

Decreases

C

Remains unchanged

D

Increases exponentially

In solid catalysed reactions the diffusional effects are more likely to affect the overall rate of reaction for

A

Fast reactions in catalyst of small pore diameter

B

Fast reaction in catalyst of large pore diameter

C

Slow reactions in catalyst of small pore diameter

D

Slow reactions in catalyst of large pore diameter

Kinetics of a solid catalysed reaction can best be studied in a __________ reactor.

A

Batch

B

Plug-flow

C

Mixed

D

None of these

If pore diffusion is the controlling step in a solid catalysed reaction, the catalyst

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