Advertisements
Advertisements
प्रश्न
Give an example where physisorption changes to chemisorption with rise in temperature. Explain the reason for change.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
Give reasons for the following observations:
Physisorption decreases with increase in temperature.
Give reason why a finely divided substance is more effective as an adsorbent.
Discuss the effect of temperature on the adsorption of gases on solids.
How does chemisorption vary with temperature?
Answer in one sentence:
Name type of adsorption in which the compound is formed.
Adsorption increases when ____________.
Powdered substances are more effective adsorbents than their crystalline forms because ____________.
Which among the following is true for chemisorption?
Chromatography is based on the principle of ____________.
Physical adsorption of a gaseous species may change to chemical adsorption with ______.
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.
What is the role of adsorption in heterogenous catalysis?
Write three differences between physisorption and chemisorption.
Which of the following statements is incorrect regarding physisorptions?
