Question

The colloidal system in which phase and dispersion medium are both liquids is known as :-
A. an emulsion
B. an aerosol
C. a gel
D. a foam

Answer 1

Hint: Dispersed phase \[ \to \] Liquid
Dispersion medium \[ \to \] Liquid
Therefore, the colloidal system is an emulsion, where emulsion is a fine dispersion of minute droplets of one liquid in another in which it is not soluble or miscible.
Here both i.e. phase and medium are liquid, so now try to remember the table of dispersion phase and medium and try to find the answer of the colloidal system.

Complete step-by-step solution:
The phase that is scattered or present in the form of colloidal particles is called the dispersed phase.
The medium in which the colloidal particles are dispersed is called the dispersion medium.
I.e., In a starch solution, starch represents the dispersed phase, while water represents the dispersion medium.

Dispersed phase	Dispersion medium	Type of colloid
Solid	Solid	Solid sol
Solid	Liquid	Sol
Solid	Gas	Aerosol
Liquid	solid	gel
Liquid	Liquid	Emulsion
Liquid	Gas	Aerosol
Gas	Solid	Solid Sol
Gas	Liquid	Foam

Emulsions are the colloidal solutions of two immiscible liquids in which one liquid acts as the dispersed phase and the other as the dispersion medium.
In emulsion, the suspended droplets (dispersed phase) are larger than the particles of dispersion medium.

\[\therefore \] Option (A) is correct answer.

Note: In this type of questions where a colloidal system is asked and in which the dispersion and phase of the medium is given, we need to know the system performing this type of activities and contains the following functions as given in the question then only we would be able to recognize the answer.
Also, we need to remember the table provided in the solution part where it is described about the combination of phase and medium of dispersion and together they form which type of colloidal system.