The effect of temperature on the adsorption of gases on solid surfaces can be understood by examining the two primary types of adsorption: physisorption and chemisorption. Both types of adsorption are influenced by temperature, but in different ways.1. Physisorption: This type of adsorption involves weak van der Waals forces between the gas molecules and the solid surface. It is a reversible process and is generally characterized by low heat of adsorption.Effect of temperature on physisorption: As temperature increases, the kinetic energy of gas molecules also increases, which in turn weakens the van der Waals forces between the gas molecules and the solid surface. Consequently, the adsorption of gas molecules on the solid surface decreases with increasing temperature. This observation is in accordance with the Langmuir adsorption isotherm, which states that the extent of adsorption is inversely proportional to the temperature.Experimental evidence: A classic example of physisorption is the adsorption of nitrogen gas on activated carbon. In an experiment, it was observed that the amount of nitrogen gas adsorbed on activated carbon decreased with increasing temperature, confirming the inverse relationship between temperature and physisorption.2. Chemisorption: This type of adsorption involves the formation of chemical bonds between the gas molecules and the solid surface, resulting in a more stable and irreversible process. It is characterized by high heat of adsorption.Effect of temperature on chemisorption: In chemisorption, the adsorption process is influenced by the activation energy required to form chemical bonds between the gas molecules and the solid surface. At low temperatures, the gas molecules may not possess enough energy to overcome the activation energy barrier, leading to low adsorption. As temperature increases, the kinetic energy of gas molecules also increases, allowing them to overcome the activation energy barrier and form chemical bonds with the solid surface. However, at very high temperatures, the adsorbed gas molecules may gain enough energy to break the chemical bonds, leading to desorption. Therefore, chemisorption typically exhibits an optimum temperature at which maximum adsorption occurs.Experimental evidence: A well-known example of chemisorption is the adsorption of hydrogen gas on a metal surface, such as palladium. In an experiment, it was observed that the amount of hydrogen gas adsorbed on the palladium surface increased with increasing temperature up to a certain point, after which it started to decrease. This behavior confirms the existence of an optimum temperature for chemisorption.In summary, the effect of temperature on the adsorption of gases on solid surfaces depends on the type of adsorption. For physisorption, adsorption generally decreases with increasing temperature, while for chemisorption, there is an optimum temperature at which maximum adsorption occurs. These observations are supported by experimental evidence from various gas-solid systems.