Q.Answer the following question.
Distinguish between Lyophobic and Lyophilic sols.

Step 1. Formation and stability. Lyophilic colloids are formed easily by simply mixing the substance with the dispersion medium and are self-stabilised, needing no added stabiliser; lyophobic colloids need special preparation methods (chemical methods, Bredig's arc, or peptization) and are inherently unstable, requiring traces of a stabiliser to remain colloidal.

Step 2. Reversibility. Lyophilic sols are reversible -- evaporating the sol and remixing the residue with the dispersion medium reforms the sol; lyophobic sols are irreversible -- once precipitated, they do not readily revert to the colloidal state.

Step 3. Visibility and coagulation. Lyophilic particles are not easily visible even under an ultramicroscope and need a large amount of electrolyte to coagulate/precipitate; lyophobic particles are easily detected under an ultramicroscope and coagulate with only a small amount of added electrolyte. …

• Reversing which type needs MORE electrolyte to coagulate -- lyophilic needs a LARGE amount (it is more stable), lyophobic needs only a SMALL amount. …