The adsorption of gases on solid surfaces is a surface phenomenon where gas molecules accumulate on the surface of a solid material. This process is influenced by various factors, including temperature. The relationship between adsorption and temperature can be described using adsorption isotherms, such as the Langmuir and Freundlich isotherms, and thermodynamic principles.As temperature increases, the adsorption behavior of gases on solid surfaces can change in the following ways:1. Physisorption: In this type of adsorption, gas molecules are held on the solid surface by weak van der Waals forces. As temperature increases, the kinetic energy of the gas molecules also increases, making it more difficult for them to be held on the surface by these weak forces. Consequently, physisorption generally decreases with increasing temperature.Experimental evidence: The adsorption of nitrogen gas on activated carbon is a classic example of physisorption. Studies have shown that as the temperature increases, the amount of nitrogen gas adsorbed on the activated carbon decreases, which is consistent with the expected behavior for physisorption.2. Chemisorption: In this type of adsorption, gas molecules form chemical bonds with the solid surface, resulting in a stronger interaction. As temperature increases, the reaction rate of the chemisorption process also increases, up to a certain point. However, if the temperature becomes too high, the adsorbed molecules may gain enough energy to break the chemical bonds and desorb from the surface, leading to a decrease in adsorption.Experimental evidence: The adsorption of hydrogen gas on metal surfaces, such as palladium or platinum, is an example of chemisorption. Studies have shown that the amount of hydrogen gas adsorbed on these metal surfaces initially increases with increasing temperature, reaching a maximum value, and then decreases as the temperature continues to rise.Theoretical explanation: The relationship between adsorption and temperature can be explained using thermodynamics. The Gibbs free energy change G of the adsorption process is related to the equilibrium constant K and temperature T by the following equation:G = -RT ln K where R is the gas constant. A negative G value indicates a spontaneous adsorption process. For physisorption, G is typically small and positive, which means that the process is more favorable at lower temperatures. For chemisorption, G is usually larger and negative, indicating that the process is more favorable at higher temperatures, up to a certain point.In conclusion, the adsorption of gases on solid surfaces is influenced by temperature, with physisorption generally decreasing and chemisorption initially increasing with temperature. Experimental evidence supports these trends, and the underlying principles can be explained using adsorption isotherms and thermodynamics.