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प्रश्न
What is the difference between physisorption and chemisorption?
Difference between physisorption and chemisorption. Give one example.
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उत्तर
| Physisorption | Chemisorption | |
| 1 | In this type of adsorption, the adsorbate is attached to the surface of the adsorbent with weak van der Waal’s forces of attraction. | In this type of adsorption, strong chemical bonds are formed between the adsorbate and the surface of the adsorbent. |
| 2 | No new compound is formed in the process. | New compounds are formed at the surface of the adsorbent. |
| 3 | It is generally found to be reversible in nature. | It is usually irreversible in nature. |
| 4 | Enthalpy of adsorption is low as weak van der Waal’s forces of attraction are involved. The values lie in the range of 20-40 kJ mol−1. | Enthalpy of adsorption is high as chemical bonds are formed. The values lie in the range of 40-400 kJ mol−1. |
| 5 | It is favoured by low-temperature conditions. | It is favoured by high-temperature conditions |
| 6 | It is an example of multi-layer adsorption | It is an example of mono-layer adsorption. |
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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
Give reasons for the following observations:
Physisorption decreases with increase in temperature.
What is the effect of temperature on chemisorption ?
Why is adsorption always exothermic?
Write any two characteristics of chemisorption.
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.
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.
Physisorption is reversible while chemisorption is irreversible. Why ?
Give reasons for the following observations :
Powdered substances are more effective adsorbents.
How does chemisorption vary with temperature?
Answer in one sentence:
Name type of adsorption in which vander Waals focres are present.
Answer in one sentence:
Name type of adsorption in which the compound is formed.
Which of the following is an example of physisorption?
Which of the following is true about chemisorption?
Adsorption increases when ____________.
Which among the following is a property of physisorption?
Powdered substances are more effective adsorbents than their crystalline forms because ____________.
Which among the following is true for chemisorption?
The extent of adsorption increases with the ____________.
The physical adsorption is due to ____________.
Which of the following is not a favourable condition for physical adsorption?
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 it important to have clean surface in surface studies?
Give an example where physisorption changes to chemisorption with rise in temperature. Explain the reason for change.
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?
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:-
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.
Which of the following statements is incorrect regarding physisorptions?
