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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
What is the effect of temperature on chemisorption ?
Why are powdered substances more effective adsorbents than their crystalline forms?
Distinguish between the meaning of the terms adsorption and absorption. Give one example of.
What is the difference between physisorption and chemisorption?
What are the factors which influence the adsorption of a gas on a solid?
Give reasons for the following observations :
Powdered substances are more effective adsorbents.
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 true about chemisorption?
In physisorption, adsorption is generally ____________.
The physical adsorption is due to ____________.
Extent of physisorption of a gas increases with ______.
In physisorption adsorbent does not show specificity for any particular gas because ______.
In which of the following reactions heterogenous catalysis is involved?
(a) \[\ce{2SO2 (g) + O2 (g) ->[NO(g)] 2SO3 (g)}\]
(b) \[\ce{2SO2 (g) ->[Pt(s)] 2SO3 (g)}\]
(c) \[\ce{N2 (g) + 3H2 (g) ->[Fe(s)] 2NH3 (g)}\]
(d) \[\ce{CH3COOCH3 (l) + H2O (l) ->[HCI(l)] CH3COOH (aq) + CH3OH (aq)}\]
Why do physisorption and chemisorption behave differently with rise in temperature?
Adsorption play no role in:-
Write three differences between physisorption and chemisorption.
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.
