Difference Between Adsorb and Absorb (With Table)

Adsorption and absorption are two chemical and physical phenomena as well which are majorly studied in the field of chemistry and physics. Both of these phenomena are referred to when two different gases, liquids, or solids get in contact with each other either chemically or physically.

Though both of the terms or phenomena sound the same, and have certain similarities as well, both of these terms are different phenomenons and have several different dissimilarities between them.

Adsorb vs Absorb

The main difference between adsorbing and absorption is that the term adsorb is referred to when the molecules of a liquid or the molecules of gas get adhered to the molecules of another liquid or molecules of a solid particle. Whereas on the other hand, the term absorb is referred to when the molecules of a liquid or the molecules of gas get assimilated into the molecules of another liquid or molecules of a solid particle.

The phenomenon of adsorption occurs when the liquid molecules of gas molecules get adsorbed onto the surface of another liquid or a solid. The term absorbs or absorption is a more known word as compared to adsorb or adsorption and is commonly used in everyday language as well.

The phenomenon of absorption occurs when the liquid molecules of gas molecules get absorbed onto the surface of another liquid or a solid. The term adsorbs or adsorption is not a very common or a much-known term. The reason behind that is that adsorption majorly occurs during chemical processes and physical processes.

Comparison Table Between Adsorb and Absorb

What is Adsorb?

When the process of adsorption occurs, the substance which adsorbs the liquid molecules or gas molecules is known as an adsorbent. While on the other hand, the liquid molecules of gas molecules that are getting adsorbed by the adsorbent are known as adsorbate.

One of the simple and easy examples of the process of adsorption can be shown when a wall gets painted with the wall. In this case, the wall which adsorbs the paint is known as adsorbent and the paint which gets adsorbed is known as adsorbate.

The process of adsorption majorly depends upon the surface area of the adsorbent. If the surface area of the adsorbent will be then the amount of adsorbate which has to be adsorbed will be higher as well.

This can be explained using the same example of paint and the wall. That is to say, if the size of the wall will be bigger, then more amount of paint will be required to completely paint the wall.

What is Absorb?

Absorption is a more common phenomenon as compared to adsorption. When the process of absorption occurs, the substance which absorbs the liquid molecules or gas molecules is known as absorbent. While on the other hand, the liquid molecules of gas molecules that are getting absorbed by the absorbent are known as absorbate.

One of the most common and the simplest example of the process of absorption is when a sponge absorbs water. In this case, the absorbent is the sponge, and the absorbate is the water.

The process of absorption majorly depends upon the volume or the size of the absorbent. If the volume of the absorbent will be higher, or the size of the absorbent will be bigger then the process of absorption will not just be faster, but also the amount of absorbate which has to be absorbed will be higher as well.

This can be explained using the same example of sponge and water. That is to say, if the size of the sponge will be bigger, then the amount of water will get absorbed more and faster as well.

Main Differences Between Adsorb and Absorb

1. The definition of the term adsorb can be stated as to when liquid molecules or gas molecules get adhered to the surface of another liquid or solid particle. While on the other hand, the definition of the term absorb can be stated as to when liquid molecules or gas molecules get assimilated into the surface of another liquid or solid particle.
2. The amount of adsorption that would occur depends upon the surface area of the substance. Whereas, the amount of adsorption that would occur depends upon the volume of the substance.
3. The phenomenon of adsorption occurs on the surface of the substance. That is why adsorption is known as a surface phenomenon. Whereas, the phenomenon of absorption occurs completely throughout the body of the substance. That is why absorption is known as the bulk phenomenon.
4. Adsorption is majorly a chemical process. While on the other hand, absorption is majorly a physical phenomenon.
5. During the process of adsorption, a certain amount of heat is released from the surface of the substance. As a result, adsorption is a type of exothermic process. On the other hand, during the process of absorption, a certain amount of heat is taken from the surface of the substance. As a result, adsorption is a type of endothermic process.
6. The concentration of the adsorbed material is uneven throughout the body of the substance and instead, it is majorly concentrated on the surface of the substance. But in the case of absorption, the concentration of the absorbing material is even throughout the body of the substance.

Conclusion

Adsorption and absorption are two different processes with different meanings. Absorption is a phenomenon that might not be able to get reversed in most cases.

While on the other hand, adsorption is a phenomenon that might get reversed in most cases. The reason behind that is that adsorption is a physical process and does not include a major interchange of atoms and molecules.

References

1. https://pubs.acs.org/doi/abs/10.1021/la950556d
2. https://pubs.rsc.org/en/content/articlehtml/2010/cc/c000900h