Effects of Pressure and Temperature on Adsorption

The adsorption process that takes place on the surface of solids has unbalanced forces and surface energy. Upon the collision of other substances with the solid material, the unbalanced materials are attracted to it and therefore remain on the solid material’s surface. The temperature and pressure have their unique effects on adsorption. Though adsorption does not freely occur everywhere on the surface of the material. There are specific surface locations called active sites where as long as there is a great contact, adsorption will continue. The adsorption rate is directly proportional to the temperature, pressure and surface area of the material. 

Adsorption

Adsorption is a process in chemistry in which mass transfer takes place of gases into a solid material or liquid surface. Adsorption meaning is that it is a type of sorption. Alternately, adsorption meaning is the capability of solids to attract molecules or ions, or atoms to themselves from the substance with which they interact. Adsorbents are those solids that adsorb gases or solutes. The molecules which have been adsorbed are known as adsorbates. An adsorbent example includes charcoal in gas masks and can help in understanding the function of an adsorbent and understanding adsorption meaning. Adsorption can be reclassified into distinct processes such as physical (physisorption) and chemical (chemisorption). The condensation of gases into the liquid phase involves the process of physical adsorption and is based on van der Waal’s forces. Chemical specificity is lacking in physisorption. Physisorption occurs when the temperature is low and the pressure is high and occurs anywhere on the surface. This process can either be a monolayer phenomenon or involve multiple layers. Chemical adsorptions on the hand do not occur on all surfaces but only on certain active sites and involve high specificity. Here, high temperature and high pressure are required. Chemisorption also involves activation energy. 

Adsorption Meaning

Adsorption meaning is a type of sorption. It occurs in solids when they are in contact with some other substance. At constant temperature and pressure, the adsorption is spontaneous. The adsorption is divided into two categories: physical and chemical adsorptions. Each has its own set of characteristics and has different effects on the variation of pressure and temperature. Adsorption can be graphed and those are called isotherms of adsorption. 

Adsorption Isotherms

The adsorption isotherms are the representation of the relation between adsorbate adsorbed and the effects of temperature and pressure. The temperature in this case remains constant while the pressure is also constant. Different types of adsorption isotherms were studied and created by different scientists. 

Langmuir Isotherm

The Langmuir isotherm is a graph representing the equilibrium between an adsorbent system and an adsorbate. It explains that in perfect isothermal conditions, an adsorbent is like a gas. In this model, adsorption, as well as description, are considered reversible phenomena. The model also represents the effects of pressure on the adsorbent. 

Conclusion

The adsorbents include a variety of materials such as colloids, metals, clay, and silica gel. The adsorption process with the effects of temperature and pressure leads to the creation of heat. This heat is released when a singular adsorbate mole is adsorbed and this entire process is known as enthalpy. Enthalpy is negative as adsorption is an exothermic phenomenon. Molecules are restricted in their movement during adoption therefore enthalpy is low. When the pressure and temperature are content then adsorption is a spontaneous process.