108. What is the difference between multimolecular and macromolecular colloids? Give one example of each. How are these two types of colloids different from these two types of colloids? 

Answer:

Multimolecular colloids:
(i) Consist of aggregates of atoms or molecules with diameter less than 10^–9 m.
(ii) The atom or molecules are held together by weak Vander Waals forces.

Macromolecular colloids:
(i) Are themselves large. Many behave as macromolecular colloids because of their large molecular masses.
(ii) Since the molecules are flexible, they can take on various shapes.

Associated colloids:

(i) Behave as true solution in smaller concentrations and colloids at higher concentrations.

(ii) Sodium stearate behaves as strong electrolyte in dilute solutions and shows the properties of sodium and stearate ions form aggregates and behave as colloids. The aggregates formed are called micelles which revert to individual ions on dilution.
Example of multi-molecular colloid: Gold sol, Sulphur sol.
Example of macro-molecular colloid:Cellulose, Starch.