Test: Adsorption (Old NCERT) - JEE MCQ

Physisorption is defined as adsorption in which force between adsorbate and adsorbent is physical van der Waals force also known as London force.

The adsorbent is that substance that gathers/adsorb molecules on its surface, and adsorbate is that substance that gets gather/adsorb by itself on the surface of the absorbent. 

Hence, Black molecules should be adsorbate.

Adsorption is a surface phenomenon where concentration of the molecules, is more on the surface than in the core.

​At the maximum adsorption, only a monolayer is formed: molecules of adsorbate do not deposit on other, already adsorbed, molecules of adsorbate, only on the free surface of the adsorbent.

Solids, particularly in a finely divided state, have a large surface area and so silica gel is a good adsorbent and keeps the leather dry and free of moisture.

Freundlich adsorption isotherm gives an empirical relationship between the quantity of gas adsorbed by the unit mass of solid adsorbent (x/m) and pressure at a specific temperature.

There is an unbalanced attractive force of adsorbent are responsible for attracting the adsorbate particles on its surface.

The formation of micelles takes place only above a particular temperature called Kraft temperature (Tk) and above a particular concentration called critical micelle concentration (CMC).

On dilution, these colloids revert back to individual ions.

Hence, option A, C is correct.

Adsorption is the adhesion (accumulation) of molecules of the gas, liquid, or dissolved solid particles (adsorbate) onto the surface (adsorbent)

The plot between the extent of adsorption (x/m) against the pressure of gas (P) at constant temperature (T) is called the adsorption isotherm.