Question

Which of the following phenomena occurs when a chalk stick is dipped in ink?
A.Adsorption of coloured substance
B.Adsorption of solvent
C.Absorption and adsorption both of solvent
D.Absorption of solvent

Answer 1

Hint: We need to understand the concept of adsorption and absorption. The adherence of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface is known as adsorption. This procedure forms an adsorbate coating on the adsorbent's surface. This contrasts from absorption, which occurs when a fluid (the ascorbate) dissolves or penetrates a liquid or solid (the absorbent). Adsorption is a surface process, whereas absorption affects the entire volume of the substance, but adsorption frequently occurs before absorption.

Complete answer:
We need to know that the term "absorption" refers to a bulk phenomena in which a material is evenly dispersed across the bulk. "Adsorption," on the other hand, is a surface phenomena in which a material accumulates exclusively on the surface and not in the bulk. When a chalk stick is dipped in ink, the ink's colour is retained on the surface due to adsorption of coloured molecules, while the ink's solvent is absorbed deeper into the stick.
Hence, option “A” and ”D” are correct.
Option “B” is incorrect because absorption of the solvent takes place rather than adsorption.
Option “C” is incorrect because only absorption of the solvent takes place.

Note:
We must note that adsorption is a surface process, whereas absorption affects the entire volume of the substance, but adsorption frequently occurs before absorption. Both processes are referred to as sorption, whereas desorption is the opposite. The terms adsorption and absorption are not interchangeable. Absorption occurs when a liquid is absorbed into a sponge, cloth, or filter paper. The liquid is absorbed fully by the absorbent substance. Individual molecules, atoms, or ions adhering to surfaces is referred to as adsorption.