Advertisements
Advertisements
Questions
What are the factors which influence the adsorption of a gas on a solid?
Describe the factors which affect the adsorption of gases on solids.
Advertisements
Solution
There are various factors that affect the rate of adsorption of a gas on a solid surface.
- Nature of the gas: Easily liquefiable gases such as NH3, HCl, etc., are adsorbed to a great extent in comparison to gases such as H2, O2, etc. This is because Van der Waal’s forces are stronger in easily liquefiable gases.
- Surface area of the solid: The greater the surface area of the adsorbent, the greater is the adsorption of a gas on the solid surface.
- Effect of pressure: Adsorption is a reversible process and is accompanied by a decrease in pressure. Therefore, adsorption increases with an increase in pressure.
- Effect of temperature: Adsorption is an exothermic process. Thus, in accordance with Le-Chatelier’s principle, the magnitude of adsorption decreases with an increase in temperature.
RELATED QUESTIONS
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.
Differentiate between adsorbtion and absorption.
What is the effect of temperature on chemisorption ?
Write any two characteristics of chemisorption.
Give reason why a finely divided substance is more effective as an adsorbent.
Physisorption is reversible while chemisorption is irreversible. Why ?
Which of the following compounds is formed when tungsten adsorbs oxygen gas?
Which of the following is an example of physisorption?
In physisorption, adsorption is generally ____________.
Chromatography is based on the principle of ____________.
Which of the following is not a favourable condition for physical adsorption?
In physisorption adsorbent does not show specificity for any particular gas because ______.
Why is it important to have clean surface in surface studies?
What is the role of diffusion in heterogenous catalysis?
What is the role of adsorption in heterogenous catalysis?
Which among the following is a false statement?
In physical adsorption, gas molecules are bound on the solid surface by
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.
