Question

Which of the following can act as a protective colloid?

• A. Gelatin
• B. Silica gel
• C. Oil-in water emulsion
• D. All the above

Answer 1

Answer: (A)

Gelatin

A colloid is a heterogeneous system in which one substance is dispersed (dispersed phase) as very fine particles in another substance called dispersion medium. The solution and colloid essentially differ from one

another by particle size.

Protective colloid is a lyophilic colloid (such as gelatin, a natural gum or a cellulose derivative) which when present in small quantities keeps lyophobic colloids from precipitating under the coagulating action of electrolytes.