During the spontaneous process of gas adsorption on a solid surface, which of the following thermody — Surface Chemistry Chemistry Question

💡 Solution & Explanation

Adsorption involves attractive interactions between the adsorbate and adsorbent, leading to a release of heat (always exothermic, so $\Delta H < 0$). The gas molecules become restricted on the surface, drastically decreasing their degrees of freedom, which lowers entropy ($\Delta S < 0$). For the process to be spontaneous, the overall Gibbs free energy change must be negative ($\Delta G < 0$).