Question

In a colloidal solution, both the dispersed phase and dispersion medium are in liquid phase. What is the type of colloid?

• A. gel
• B. emulsion
• C. foam
• D. aerosol

Hint:

Types of Colloidal Systems: \begin{tabular}{|l|l|l|} \hline Dispersed Phase & Dispersion Medium & Type of Colloid & Example
\hline Solid & Solid & Solid sol & Some colored glasses, gemstones
Solid & Liquid & Sol (or Gel if network) & Paint, cell fluids, ink
Solid & Gas & Aerosol & Smoke, dust
Liquid & Solid & Gel & Cheese, butter, jellies
Liquid & Liquid & Emulsion & Milk, hair cream, mayonnaise
Liquid & Gas & Aerosol (liquid) & Fog, mist, cloud, insecticide sprays
Gas & Solid & Solid foam & Pumice stone, foam rubber
Gas & Liquid & Foam & Whipped cream, soap lather
\hline \end{tabular} (Gas in Gas forms a true solution, not a colloid).

Answer 1

The Correct Option is B

Colloidal solutions are classified based on the physical state of the dispersed phase and the dispersion medium.
- Gel: Dispersed phase is liquid, dispersion medium is solid.
(e.
g.
, jelly, cheese, butter).
- Emulsion: Dispersed phase is liquid, dispersion medium is liquid.
(e.
g.
, milk, hair cream, mayonnaise).
- Foam: Dispersed phase is gas, dispersion medium is liquid.
(e.
g.
, whipped cream, soap lather).
(Solid foam: Dispersed phase gas, medium solid, e.
g.
, pumice stone, styrofoam).
- Aerosol: Dispersed phase is solid or liquid, dispersion medium is gas.
- Liquid in Gas (e.
g.
, fog, mist, clouds, hair sprays).
- Solid in Gas (e.
g.
, smoke, dust).
The question states that both the dispersed phase and the dispersion medium are in the liquid phase.
This type of colloid is called an emulsion.
This matches option (2).