Page 1 - 3. Lesson Note-Colloids and their properties

SAI International School
Subject-Chemistry

Ch-Is Matter around us pure?
Topic-Colloids and their properties
LESSON NOTE

Colloids
A solution in which the size of solute particles is intermediate between those in true
solution and suspension is called as Colloids.
For Example: Soap Solution, Starch solution, milk, Blood, ink etc.
Colloid has two components, they are: Dispersed phase and Dispersion medium
Dispersed phase: The phase that is scattered or present in the form of colloidal
particles is called the dispersed phase.
Dispersion medium: The medium in which the colloidal particles are dispersed is
called the dispersion medium.
Properties of Colloids
1) They appear to be homogeneous but actually they are heterogeneous when

observed under microscope.

2) They are not perfectly transparent,it is somewhat translucent.
3) The particles cannot be seen by naked eyes or microscope.

4) The particles do not settle on keeping.
5) The particles cannot be separated by filtration.

6) The particles are big enough to scatter light.
7) The size of particles is bigger than those of true solution but smaller than

suspension.

Difference between Colloids and True solutions