The following statements relate to the adsorption of gases on a solid surface. Identify the incorrect statement among them:
Enthalpy of adsorption is negative.
On adsorption, the residual forces on the surface are increased.
On adsorption, decrease in surface energy appears as heat.
Entropy of adsorption is negative.

(A) Enthalpy of adsorption is negative as heat is liberated during adsorption. The process is exothermic. Hence, statement A is correct (B) On adsorption, the residual forces on the surface are decreased as the surface is covered with the substance being adsorbed which develops forces between absorbate and adsorbent. Hence, statement B is incorrect (C) On adsorption decreases in surface energy appears as heat. This makes the process exothermic. Thus, statement C is correct (D) Entropy of adsorption is negative as there is a decrease in the disorder. Hence, the statement D is correct.