Question

A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium classified as:
(A) Solid sol
(B) Gel
(C) Emulsion
(D) Sol

Answer 1

Hint: 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 essential difference between a solution and a colloid is that of particle size. Colloidal particles have an enormous surface area per unit mass as a result of their small size.

Complete step by step answer:
Colloids are classified based on the following criteria:
(a) The physical state of the dispersed phase and a dispersion medium
(b) Natural of interaction between the dispersed phase and a dispersion medium
(c) Type of particles of the dispersed phase.
Classification based on the physical state of the dispersed phase and dispersion medium:
Depending upon whether the dispersed phase and dispersion medium are solids, liquids, or gases. Eight types of colloidal systems are possible.
The examples of the various types of colloids along with their typical names are listed in the table below.

Dispersion phase	Dispersion medium	Types of colloid	examples
Solid	Solid	Solid sol	Some colored gases and gemstones
Solid	Liquid	Sol	Paints, cell fluids
Solid	Gas	aerosol	Smoke, dust
Liquid	Solid	Gel	Cheese, butter
Liquid	Liquid	Emulsion	Milk, hair cream
Liquid	Gas	Aerosol	Fog, cloud, mist
Gas	Solid	Solid sol	Foam rubber
Gas	Liquid	Foam	Froth, soap lather

Out of the various types of colloids in a given table, the most common are sols, gels, and emulsions. Hence, from the above table, A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium classified as ‘sol’. So, the correct answer is “Option D”.
Note: A gas mixed with other gas forms a homogeneous mixture and hence this system is not a colloidal system. If the dispersion medium is water, the sol is called aquasol or hydrosol and if the dispersion medium is alcohol, it is called alcosol and so on.