Physical Properties of colloidal solutions
The main characteristic properties of colloidal solutions are as follows.
(i) Heterogeneous nature: Colloidal sols are heterogeneousin nature. They consists of two phases; the dispersed phase and the dispersion medium.
(ii) Stable nature: The colloidal solutions are quite stable. Their particles are in a state of motion and do not settle down at the bottom of the container.
(iii) Filterability: Colloidal particles are readily passed through the ordinary filter papers. However they can be retained by special filters known as ultrafilters (parchment paper).
(2) Colligative properties
(i) Due to formation of associated molecules, observed values of colligative properties like relative decrease in vapour pressure, elevation in boiling point, depression in freezing point, osmotic pressure are smaller than expected.
(ii) For a given colloidal sol the number of particles will be very small as compared to the true solution.