Question

Which of the following can act as a protective colloid?
A. Gelatin
B. Silica gel
C. Oil in water emulsion
D. All of the above

Answer 1

Hint: We should recall the nature of lyophilic colloids against lyophobic colloids. The presence of lyophilic colloids is advantageous for lyophobic colloids. Also, we will look into the definition of colloids to have a better understanding of the question.

Complete Step by Step Solution:
In a heterogeneous system known as a colloid, one component is distributed (or the dispersed phase) as very small particles in another substance called the dispersion medium. The main distinction between the solution and colloid is the size of the particles.

We should be aware that a protective colloid is a lyophilic colloid that prevents lyophobic colloids from precipitating under the coagulating action of electrolytes when it is present in tiny amounts. Lyophilic sols are more stable than lyophobic sols.Colloidal particles are encased in a sheath of the liquid in which they are disseminated because lyophilic colloids are extensively solvated.

We should keep in mind how lyophilic colloids differ from lyophobic colloids. Lyophobic colloids benefit from the presence of lyophilic colloids.
A protective colloid is a lyophilic colloid that prevents lyophobic colloids from precipitating due to the coagulating effects of electrolytes when it is present in modest amounts. Examples include gelatin, a natural gum, or a cellulose derivative.
So, option A is correct.

Note: Lyophilic colloids are colloids that enjoy solvents. The dispersed phase of lyophilic colloids has a favourable affinity for the dispersion medium (solvent). Because so many hydrogen bonds are formed, dispersed particles have a strong attraction for the dispersed medium. Example: Protein or starch dissolved in water. It is significantly simpler to make lyophilic colloids by combining the particle with the dispersion medium.