A. Film diffusion
B. Diffusion through ash layer
C. Chemical reaction
D. Either A., B. or C.
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. - The rate controlling step for the heterogeneous irreversible catalytic reaction A(g) + B(g) → C(g) is the surface reaction of absorbed A with absorbed B to give adsorbed C. The rate expression for this reaction can then be written as (where, KA, KB and KC are the equilibrium constants and is the rate constant of the rate controlling step) ?
A. k KA pApB / (1 + KApA + KBpB)
B. k KAKB pApB / (1 + KApA + KBpB)
C. k KAKB pApB / (1 + KApA + KBpB + KCpC)
D. k KAKB pApB / (1 + KApA + KBpB + KCpC)2 - For a vapour phase catalytic reaction (A + B → P) which follows the Ridel mechanism and the reaction step is rate controlling, the rate of reaction is given by (reaction rate is irreversible, product also absorbs) ?
A. -rA = (k . PA . PB)/(1 + KAPA + KPPP)
B. -rA = (k . PA
2 – k1PP)/(1 + KAPA + KPPP)
C. -rA = (k . PA . PB)/(1 + KAPB + KBPB . KPPP)
D. -rA = (k . PA . PB)/(1 + KAPA) - ____________ is the controlling step in a highly temperature sensitive fluid-solid non-catalytic reaction ?
A. Gas film diffusion
B. Ash diffusion
C. Chemical reaction
D. None of these - The fractional volume change between no conversion and complete conversion, for the isothermal gas phase reaction, 2A → R, is___________________?
A. 0.5
B. -0.5
C. 1
D. 1.5 - The fractional volume change of the system for the isothermal gas phase reaction, A → 3B, between no conversion and complete conversion is___________________?
A. 0.5
B. 1
C. 2
D. 3 - Overall rate of reaction in a heterogeneous catalytic reaction depends upon the mass and energy transfer from the fluid to solid surface and its rate of reaction is usually ________________ the concentration of catalyst, if it does not entail a chain mechanism?
A. Proportional to
B. Independent of
C. Inversely proportional to
D. Proportional to the square of - 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 chemical reaction, A → 3B, is conducted in a constant pressure vessel. Starting with pure A, the volume of the reaction mixture increases 3 times in 6 minutes. The fractional conversion is ___________________?
A. 0.33
B. 0.5
C. 1
D. Data insufficient, can’t be predicted - 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
