Methylene blue, from its aqueous solution, is adsorbed on activated charcoal at 25 o C. For this process, the correct statement is

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TestHub · Accepted Answer

It is the process of Physical adsorption as charcoal is already activated.
Since physical adsorption is spontaneous $Δ G$ is -ve
$Δ G = Δ H - T Δ S$
as $Δ S$ is -ve (passage of methylene blue from aqueous phase over the surface of adsorbent) i.e. $Δ H$ is highly -ve since process is exothermic in nature.

Physical adsorption is reversible in nature.

Physical adsorption decreases with increase in temperature.

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