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प्रश्न
What is the role of adsorption in heterogenous catalysis?
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उत्तर
The role of heterogeneous catalysts can be explained in terms of adsorption of reactants on the surface of the catalyst.
The adsorption helps the reaction in the following ways:
(i) Adsorption increases the concentration of reactants on the surface of the catalyst. Due to increased concentration of the reactants, the reactions proceed rapidly.
(ii) Adsorbed molecules get dissociated to form active species like free radicals which react faster than molecules.
(iii) The adsorbed molecules are not free to move about and, therefore, they collide with other molecules on the surface.
(iv) The heat of adsorption evolved acts as energy of activation for the reaction (chemisorption).
Example: Adsorption of molecules of the reactant at the active site.
Occurrence of chemical reaction on the surface of catalyst
Desorption of product molecules
Example:
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संबंधित प्रश्न
Write the differences between physisorption and chemisorption with respect to the following:
(i) Specificity
(ii) Temperature dependence
(iii) Reversibility and
(iv) Enthalpy change
Differentiate between adsorbtion and absorption.
What is the effect of temperature on chemisorption ?
Why is adsorption always exothermic?
Give reasons for the following observations :
Powdered substances are more effective adsorbents.
How does chemisorption vary with temperature?
How does chemisorption vary with temperature?
Answer in one sentence:
Name type of adsorption in which vander Waals focres are present.
Which of the following compounds is formed when tungsten adsorbs oxygen gas?
Which of the following is an example of physisorption?
Powdered substances are more effective adsorbents than their crystalline forms because ____________.
Extent of physisorption of a gas increases with ______.
Physical adsorption of a gaseous species may change to chemical adsorption with ______.
In physisorption adsorbent does not show specificity for any particular gas because ______.
Why is chemisorption referred to as activated adsorption?
Which among the following is a false statement?
Chromatography is based on:-
Adsorption play no role in:-
Assertion A : Activated charcoal adsorbs SO2 more efficiently than CH4.
Reason R : Gases with lower critical temperatures are readily adsorbed by activated charcoal.
In light of the above statements, choose the correct answer from the options given below.
