Question

What is physical adsorption?

Answer 1

Hint: The adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface is known as adsorption. Now, depending on the nature of the interaction between the adsorbate and the adsorbent and the properties of adsorbate physical and chemical adsorption are classified.

Complete Step by Step Answer:
The adsorption where the adsorption takes place between the adsorbate and adsorbent due to weak hydrogen bonding or van der waal’s force is defined as the physical adsorption.
The properties of physical adsorption are as follows-
1. It has weak forces like vander waals force or hydrogen bonding between adsorbate and adsorbent.
 2. Physical adsorption is reversible in nature.
3. Physical adsorption depends on the surface area of the adsorbent because as the surface area of the adsorbent will increase, physical adsorption additionally will increase.
4. Physical adsorption is the slowest process.
5. It is not independent of temperature. It increases with a decrease in temperature.
6. It is highly specific.
7. It is spontaneous and has negative enthalpy and entropy.

Note: Adsorption is two types. One is physical adsorption where a weak vanderwal bond or hydrogen bond is present between adsorbate and adsorbent. It is dependent on temperature as it has physical bonds which vibrate in presence of high temperature.