Which of the following observations are true in case of adsorption from the solution phase?
I. The extent of adsorption decreases with an increase of temperature.
Il. The extent of adsorption depends upon the concentration of the solute in solution.
III. The extent of adsorption increases with the decrease in surface area of adsorbent.
      Select the correct option.

Adsorption is exothermic process but reverse process i.e., desorption is endothermic. An increase in temperature will favour the desorption process because molecules of the adsorbate get energy and leave the surface so rate of adsorption decreases with increase in temperature.

Increase in amount of adsorption in solution as amount. As amount of adsorbate in the solution increases interaction of adsorbate with adsorbent increase which led to increase in extent of adsorption.