Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at 25°C. For this proce — Surface Chemistry Chemistry Question

💡 Solution & Explanation

Adsorption of methylene blue on charcoal from a solution is a spontaneous process of physical adsorption. Because it is spontaneous and limits the freedom of particles (decreased entropy), the change in enthalpy (ΔH) must be negative to satisfy ΔG = ΔH - TΔS < 0. Therefore, correct answer is B.