A. Decreases the activation energy
B. Alters the reaction mechanism
C. Increases the frequency of collisions of reacting species
D. All A., B. and C.
Correct Answer: D. All A., B. and C. ✔
Last Updated: February 19, 2019
Related MCQs
- The following gas phase reaction is taking place in a plug flow reactor. A stoichiometric mixture of A and B at 300 K is fed to the reactor. At 1 m along the length of the reactor, the temperature is 360 K. The pressure drop is negligible and an ideal gas behaviour can be assumed. Identify the correct expression relating the concentration of A at the inlet (CA0), concentration of A at 1m (CA) and the corresponding conversion of A (X) ?
- Mean residence time is equal to the space time, when__________?
- In a chemical reaction, represented by as shown in the bellow figure, it is observed that the (i) Rate of reaction increases by a factor of 4 on doubling the concentration of the reactant. (ii) Rate of reaction increases by a factor of 9 on trebling the concentration of the reactant. Then the rate of the reaction is proportional to(where, CA = concentration of the reactant)__________?
- Knudsen diffusion is directly proportional to __________?
- Exposure of a photographic plate to produce a latent image is an example of __________ reaction?
- In case of calcination of limestone, CaCO3 CaO + CO2, the addition of more of CaO will result in __________ in the concentration of CO2?
- The rate of the chemical reaction A → B doubles as the concentration of A i.e.., CA is doubled. If rate of reaction is proportional to CA n, then what is the value of n for this reaction ?
- Arrhenius equation shows the variation of __________ with temperature?
- The rate constant of a chemical reaction increases by increasing the__________?
- What is the dispersion number for a CSTR ?
- Catalyst is a substance, which __________ chemical reaction?
- __________ gas is normally employed in B.E.T. method of finding out the surface area of catalyst?
- The equilibrium constant of a catalytic chemical reaction __________ due to the presence of?
- 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 second order liquid phase reaction, A → B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume of the reacting mixture is V and the density of the liquid mixture is constant. The mass balance for A is__________?
- For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the__________?
- Batch process is preferred over continuous process, when the__________?
- Rate of a chemical reaction is not affected by the__________?
- On application of pressure to the equilibrium system, ice ⇌ water; which of the following phenomenon will occur ?
- B.E.T. method can be used to determine the __________ of a porous catalyst?
- In an exothermic reaction, the energy of the reacting substances as compared to that of products is__________?
- Semibatch reactor is preferred, when a/an__________?
- The half life period ‘t’ of a zero order reaction as shown in the bellow figure, is equal to__________?
- If a solid-gas non-catalytic reaction occurs at very high temperature, the rate controlling step is the __________ diffusion?
- Variables affecting the rate of homogeneous reactions are__________?
- In a zero order reaction, reactants concentration does not change with time and the__________?
- In case of the irreversible unimolecular type, first order reaction, the fractional conversion at any time for constant volume system as compared to variable volume system is__________?
- Volume change for unimolecular type first order reaction as shown in the bellow figure, increases __________ with time?
- 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 ?
- An example of autothermal reactor operation is__________?
- A first order reaction is to be treated in a series of two mixed reactors. The total volume of the two reactors is minimum, when the reactors are__________?
- __________ resistance is not involved in the combustion of a carbon particle?
- The value of ‘n’ for a chemical reaction A → B, whose reaction rate is → CA n, will be __________ if the rate of the reaction increases by a factor of 8, when the concentration of is doubled?
- A photochemical reaction is __________ light?
- Participation of __________ is involved in the occurrence of a chemical reaction?
- The first order series reaction as shown in the bellow figure is conducted in a batch reactor. The initial concentrations of A, B and C (CA0, CB0, CC0 respectively) are all non-zero. The variation of CB with reaction time will not show a maximum, if__________?
- In a first order reaction, the time required to reduce the concentration of reactant from 1 mole/litre to 0.5 mole/litre will be __________ that required to reduce it from 10 moles/litre to 5 moles/litre in the same volume ?