Question

The charge on colloidal particles is due to the preferential adsorption of ions.
A. True
B. False

Answer 1

Colloidal particles can be defined as the particles having the size of particles in between the range 1 to 1000 nanometres. The solutions contain the insoluble suspended particles due to their size. Colloidal particles will not settle down in the solution like suspensions. These are heterogeneous due to insolubility.

Complete step by step answer:
Colloidal particles are of two types based on stability i.e. lyophilic sols and lyophobic sols. These sols are considered to be stable in the absence of electrolyte in the solution. Colloidal sols have some type of electrical charge on it. Let us explain it with the help of an example. For example, we have a sol of ferric hydroxide, so here positively charged particles are of ferric hydroxide whereas dispersion medium has negatively charged particles.
The charge on sol is the basic reason for the stability of colloidal sols. The charge on the sol is due to some reasons:
When adsorbed molecular electrolytes are dissociated
When there is the dissociation of molecules forming colloidal aggregates
Due to preferential adsorption of ions in solution
Let us take an example again of ferric hydroxide sol. It is prepared by the reaction of ferric chloride in warm water. The ferric ions i.e. Fe (III) will be adsorbed preferably by the colloidal solution of ferric hydroxide as these ions are common in the lattice of ferric hydroxide.
In the last, we can say that the charge on colloidal particles is due to the preferential adsorption of ions.

So, the statement is true.

Note: There are other properties exhibited by colloidal particles. Tyndall effect and Brownian motion are one of them. Colloidal particles can exhibit the optical property i.e. Tyndall effect. When a beam of light is passed through the colloidal solution must be kept in dark, the light will show illumination. This process is termed as a Tyndall effect.