Adsorption and desorption are chemical processes that are opposite to each other. We can observe these processes in many biological, physical and chemical systems. It can occur naturally or we can perform adsorption and desorption for chemical experiments. Overview and Key Difference 2. What is Adsorption 3. What is Desorption 4. Adsorption refers to the process by which some solids hold molecules of a gas or liquid or solute as a thin film.
Therefore, it is the process of adhesion of molecules onto a surface. The adsorption process is a surface phenomenon. Desorption is the reverse of the adsorption.
Furthermore, adsorption is a consequence of surface energy. We can classify adsorption into two groups as chemisorption and physisorption. Taken together, these are called physical adsorption. The adsorption is rapid and reversible, which means it can be easily desorbed by heating or decompression. Physical adsorption is weak, multilayer, non-directional and non-specific. Was this answer helpful? Begin typing your search term above and press enter to search.
Press ESC to cancel. Skip to content Home Physics What is the difference between absorption and desorption? Ben Davis May 6, What is the difference between absorption and desorption? What is absorption and desorption?
What are the types of adsorption? Sorption describes the actions of absorption and adsorption - desorption is the opposite of sorption. Adsorption and absorption are important processes that occur in chemistry and biology. It is important to have an understanding of both processes and the differences between them when considering separation protocols, particularly in gas and liquid chromatography.
The major difference between adsorption and absorption is that one is a surface process and the other a bulk process. Adsorption is a surface process, the accumulation of a gas or liquid on a liquid or solid. Adsorption can be defined further based on the strength of the interaction between the adsorbent the substrate onto which chemicals attach and the adsorbed molecules.
Chemisorption involves more energy than physisorption. The difference between the two processes is loosely based on the binding energy of the interaction. Absorption is a phenomenon involving the bulk properties of a solid, liquid or gas.
It involves atoms or molecules crossing the surface and entering the volume of the material. As in adsorption, there can be physical and chemical absorption. Desorption is the release of one substance from another, either from the surface or through the surface. Desorption can occur when an equilibrium situation is altered. Imagine a tank of water in equilibrium with its surroundings.
The amount of oxygen entering and leaving the water from the air will be the same — and the oxygen concentration in the water will be constant. If the water temperature increases, the equilibrium and solubility are changed, and the oxygen will desorb from the water — lowering the oxygen content.
Adsorption and desorption are the main processes operating in chromatography. It is the relative rates of adsorption and desorption onto and off the stationary phase that allows chemicals in samples to be separated. If the column conditions favour adsorption of a molecule, then the molecule will adhere to the stationary phase and be separated from the other sample chemicals. When the conditions favour desorption, the opposite will happen — and the chemicals will be released into the mobile phase.
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