Question

Give reason for the following:

Lyophilic colloidal solutions are more stable than lyophobic colloidal solutions.

Answer 1

Lyophilic colloidal solutions are more stable than lyophobic colloidal solutions because lyophilic colloids are extensively solvated, i.e., the colloidal particles are covered by a sheath of the liquid in which they are dispersed. When a lyophilic sol is added to the lyophobic sol, the lyophilic particles form a layer around lyophobic particles and, thus, protect the latter from electrolytes. In lyophilic colloids, disperse phase has a high affinity for dispersion medium whereas in lyophobic colloids, disperse phase has a low affinity for dispersion medium.