Question

Name the potential difference between the fixed charged layer and diffused layer having opposite charge
A) Colloidal potential
B) Zeta potential
C) Electrostatic potential
D) None of these

Answer 1

The colloidal particle’s surface acquires an electrical double layer due to selective adsorption of ions. The potential difference between the fixed charged layer and diffused layer of opposite charge is also called electrokinetic potential.

Complete step by step answer:
Colloidal solutions contain traces of electrolyte which makes the sols stable. If it is removed the sols become unstable. The charge on the colloidal particle is generally acquired by adsorbing positive or negative ions from electrolyte.
When a colloidal particle absorbs the ions present in the electrolyte by selective adsorption of either ions of positive or negative charge, a fixed layer is formed on the surface of the colloidal particle. The ions left behind combine together to form a diffused layer.
Thus an electrical double layer is formed in which one is a fixed layer and other is mobile.This layer is known as Helmholtz double layer.
The potential difference formed between these 2 layers due to opposite charge is called Zeta potential or electro-kinetic potential.

Hence the correct answer is B.

Additional Information:
Zeta potential is represented by Z. The magnitude of zeta potential is given by-
$\Rightarrow {\text{Z = }}\dfrac{{4\pi \eta {\text{u}}}}{{\text{D}}}$
Where $\eta$ is the coefficient of viscosity, D is dielectric constant, u is the velocity of colloidal particles under influence of applied electric field.

Note:
The electrostatic potential and electrokinetic potential are different as kinetic means movement whereas static refers to fixed in place. So we should not be confused between them. Zeta potential is used to-
-Evaluate the charge stability of liposomes which is a dispersed system.
-Evaluate magnitude of electrical charge of lipid bilayer.