Distinction between lyophilic and lyophobic sols
Property | Lyophilic sols (suspensoid) | Lyophobic sols (Emulsoid) |
Surface tension | Lower than that of the medium | Same as that of the medium |
Viscosity | Much higher than that of the medium | Same as that of the medium |
Reversibility | Reversible | Irreversible |
Stability | More stable | Less stable |
Visibility | Particles can’t be detected even under ultramicroscope | Particles can be detected under ultramicroscope. |
Migration | Particles may migrate in either direction or do not migrate in an electric field because do not carry any charge. | Particles migrate either towards cathode or anode in an electric field because they carry charge. |
Action of electrolyte | Addition of smaller quantity of electrolyte has little effect | Coagulation takes place |
Hydration | Extensive hydration takes place | No hydration |
Examples | Gum, gelatin, starch, proteins, rubber etc. | Metals like Ag and Au, hydroxides like |
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metal sulphides like