Question

The incorrect statement about physical adsorption is that :

• A. it lacks specificity
• B. it is generally reversible
• C. porous surfaces are good adsorbent
• D. heat of adsorption is quite high

Answer 1

The correct option is D heat of adsorption is quite high

If the accumulation of gas on the surface of a solid occurs on account of weak van der Waals’ forces, the adsorption is termed as physical adsorption or physisorption.

Characteristics of Physisorption are-

• It is not Specific in nature.
• It is a Reversible process.
• It is not specific in nature.
• It depends on the nature of gas. More easily liquefiable gases are adsorbed readily.
• Enthalpy of adsorption is low.
  
• Low temperature is favourable for adsorption.
  
• There is no necessity of activation energy.
• It depends on the surface area. Hence, porous surfaces are good adsorbents.
  

So, here option D is the wrong statement about Physisorption.