Identify the strictly true statements regarding the spontaneity and energetics of adsorption from a — Surface Chemistry Chemistry Question

💡 Solution & Explanation

Statement A is true: since $\Delta S < 0$ and $T$ is positive (Kelvin scale), $T\Delta S$ is strictly negative. Statement B is false: $\Delta H$ must be negative to overcome the unfavorable entropy change. Statement C is true: as sites fill up, the strongest active sites go first, so less heat is released per mole later on. Statement D is true: an endothermic process ($\Delta H > 0$) combined with $\Delta S < 0$ would make $\Delta G > 0$ at all temperatures, making spontaneous adsorption physically impossible.