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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
Why is adsorption always exothermic?
Give reason why a finely divided substance is more effective as an adsorbent.
What are the factors which influence the adsorption of a gas on a solid?
Discuss the effect of temperature on the adsorption of gases on solids.
How does chemisorption vary with temperature?
Which among the following is a property of physisorption?
Which among the following is true for 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 is chemisorption referred to as activated adsorption?
What is the role of diffusion in heterogenous catalysis?
A plot of 10 g (x/m) versus 10 g p for the adsorption of a gas on the surface of a solid gives a straight line with slope equal to:-
Chromatography is based on:-
Which of the following statements is not true about physisorption?
