Explain the phenomenon that involves solutes from solution being adsorbed on solid adsorbents.

(N/A) Solids can also adsorb solutes from solutions. When a solution of acetic acid in water is shaken with charcoal,a part of the acid is adsorbed by the charcoal,and the concentration of the acid decreases in the solution. Similarly,a litmus solution becomes colourless when shaken with charcoal.
The precipitate of $Mg(OH)_{2}$ attains a blue colour when precipitated in the presence of a magneson reagent. This colour is due to the adsorption of the magneson. The following observations have been made regarding adsorption from the solution phase:
$(i)$ The extent of adsorption decreases with an increase in temperature.
$(ii)$ The extent of adsorption increases with an increase in the surface area of the adsorbent.
$(iii)$ The extent of adsorption depends on the concentration of the solute in the solution.
$(iv)$ The extent of adsorption depends on the nature of the adsorbent and the adsorbate.
The precise mechanism of adsorption from solution is not fully known. Freundlich's equation approximately describes the behaviour of adsorption from solution,with the difference that instead of pressure,the concentration of the solution is taken into account,i.e.,$\frac{x}{m} = k C^{\frac{1}{n}}$,where $C$ is the equilibrium concentration. Taking the logarithm of the above equation,we get: $\log \frac{x}{m} = \log k + \frac{1}{n} \log C$.
Plotting $\log \frac{x}{m}$ against $\log C$ yields a straight line,which confirms the validity of the Freundlich isotherm. This can be tested experimentally by using solutions of acetic acid with different concentrations. Equal volumes of solutions are added to equal amounts of charcoal in different flasks. The final concentration is determined in each flask after adsorption. The difference between the initial and final concentrations gives the value of $x$. Using the above equation,the validity of the Freundlich isotherm can be established.