5.14 How are colloids classified on the basis of

(i) physical states of components

(ii) nature of dispersed phase and

(iii) interaction between dispersed phase and dispersion medium?

(i) On the basis of the physical state of the components (by components we mean the dispersed phase and dispersion medium). Depending on whether the components are solids, liquids, or gases, we can have eight types of colloids.

Dispersed phase Dispersion medium  Type of colloid Example
1. Solid Solid Solid Sol

Gemstone

2. Solid Liquid Sol

Paint

3. Solid Gas Aerosol

Smoke

4. Liquid Solid Gel

Cheese

5.

Liquid Liquid Emulsion Milk
6. Liquid Gas Asrosol

Fog

7. Gas Solid Solid foam

Pumice stone

8. Gas Liquid Foam

Froth


(ii) On the basis of the dispersion medium, sols can be divided as:

Dispersion Medium

Name of sol

Water

Aquasol or hydrosol

Alcohol

Alcosol

Benzene

Benzosol

Gases

Aerosol


(iii) On the basis of the nature of the interaction between the dispersed phase and dispersion medium, the colloids can be classified as lyophilic (solvent attracting) and lyophobic (solvent repelling).