Give reasons for the following observations:

(i) A delta is formed at the meeting point of sea water and river water.

(ii) NH₃ gas adsorbs more readily than N₂ gas on the surface of charcoal.

(iii) Powdered substances are more effective adsorbents.

(i) Sea water is made of numerous electrolytes while river water is a colloidal solution of clay. When sea water meets river water, electrolytes in sea water coagulate colloidal solution of clay in river water which results in the deposition and formation of delta.

(ii) Easily Liquefiable gases (gases with high critical temperature) are adsorbed easily since there is more van der Waal’s force. NH₃ gas has high critical temperature while N₂ is comparatively inert. Therefore, NH₃ gas adsorbs more readily than N₂ gas on the surface of charcoal.

(iii) Adsorption is a surface phenomenon i.e., it occurs only at the surface of the adsorbent. Substances has larger surface area when powdered rather than in bulk. Adsorption is directly proportional to the surface area per unit mass of the adsorbent. Therefore, powdered substances are more effective adsorbents.