Question

Adsorption of a gas on the surface of solid is generally accompained by a decrease in entropy. Still a spontaneous process. Explain.

Answer 1

According to the equation;

$△G=△H-T△S$

For a process to be spontaneous, $△G$ should be negative. Even though $△S$ is negative here, $△G$ is negative because the reaction is highly exothermic, i.e., $△H$ is negative.