The number of incorrect statement/s from the following is/are
A. Water vapours are adsorbed by anhydrous calcium chloride.
B. There is a decrease in surface energy during adsorption.
C. As the adsorption proceeds, $$\Delta$$H becomes more and more negative.
D. Adsorption is accompanied by decrease in entropy of the system.

Let us examine each statement about adsorption:

Statement A: "Water vapours are adsorbed by anhydrous calcium chloride." This is incorrect. Anhydrous $$CaCl_2$$ actually absorbs water vapour (it takes water into its bulk to form hydrated salts like $$CaCl_2 \cdot 6H_2O$$), rather than adsorbing it on the surface. Adsorption is a surface phenomenon, while what $$CaCl_2$$ does is absorption — a bulk phenomenon.

Statement B: "There is a decrease in surface energy during adsorption." This is correct. Adsorption occurs because surface molecules have unbalanced forces. When adsorbate molecules attach to the surface, these residual forces are satisfied, lowering the surface energy.

Statement C: "As the adsorption proceeds, $$\Delta H$$ becomes more and more negative." This is correct. Adsorption is exothermic, and as the process continues, the cumulative enthalpy change becomes increasingly negative.

Statement D: "Adsorption is accompanied by decrease in entropy of the system." This is correct. Gas molecules lose their freedom of movement when they become bound to a surface, resulting in decreased randomness and hence decreased entropy.

Only Statement A is incorrect. The number of incorrect statements is $$\boxed{1}$$.