Question
Chemistry Question on Surface Chemistry
Which of the following is not the characteristic of physisorption?
A
It arises because of vander Waals forces.
B
It is not specific in nature.
C
Enthalpy of adsorption is high.
D
It results into multi molecular layers on adsorbent surface under high pressure.
Answer
Enthalpy of adsorption is high.
Explanation
Solution
The characteristic of physisorption that is not correct is:
Enthalpy of adsorption is high.
Physisorption is characterized by weak van der Waals forces between the adsorbent and the adsorbate. As a result, the enthalpy of adsorption in physisorption is relatively low. The other options are correct:
- Physisorption arises because of van der Waals forces.
- Physisorption is not specific in nature.
- Physisorption can result in the formation of multi-molecular layers on the adsorbent surface under high pressure.