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प्रश्न
Give an example where physisorption changes to chemisorption with rise in temperature. Explain the reason for change.
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उत्तर
The process of physisorption for example that of H2 on finely divided nickel, involves weak van der Waals’ forces. With increase in temperature, hydrogen molecules dissociate into hydrogen atoms which are held on the surface by chemisorption.
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संबंधित प्रश्न
Give reasons for the following observations:
Physisorption decreases with increase in temperature.
Distinguish between the meaning of the terms adsorption and absorption. Give one example of.
Give reason why a finely divided substance is more effective as an adsorbent.
Physisorption is reversible while chemisorption is irreversible. Why ?
Answer in one sentence:
Name type of adsorption in which the compound is formed.
Which of the following compounds is formed when tungsten adsorbs oxygen gas?
Powdered substances are more effective adsorbents than their crystalline forms because ____________.
Which among the following is true for chemisorption?
In physisorption, adsorption is generally ____________.
Chromatography is based on the principle of ____________.
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 it important to have clean surface in surface studies?
Why is chemisorption referred to as activated adsorption?
What is the role of diffusion in heterogenous catalysis?
Assertion: Detergents with low CMC are more economical to use.
Reason: Cleansing action of detergents involves the formation of micelles. These are formed when the concentration of detergents becomes equal to CMC.
In physical adsorption, gas molecules are bound on the solid surface by
Adsorption play no role in:-
Which of the following statements is incorrect regarding physisorptions?
Which of the following statements is not true about physisorption?
