surface tension of dp is equal to dm in lyophobic sols

Dear Student,

Examples

Lyophilic : Sols of organic substances like gelatin, gum, starch and proteins.

Lyophobic : Sols of inorganic substances like Arsenic (As₂S₃), Iron (Fe(OH)₃) and Platinum.

Ease of Preparation

Lyophilic : As these colloids are liquid loving, their sols are easy to prepare and can be prepared directly by mixing colloid with liquid. Additional stabilizers are not required during their preparation.

Lyophobic : As these colloids are water hating, their sols are easy to prepare and cannot be prepared directly by mixing colloid with liquid. Special methods are employed to prepare lyophobic sols and additional stabilizers are required during their preparation.

Stability

Lyophilic : Lyophilic sols are relatively stable as strong forces of interaction exist between colloidal particles and liquid.

Lyophobic : Lyophobic sols are less stable as weak forces of interaction exist between colloidal particles and liquid.

Charge

Lyophilic : The charge on the lyophilic sol depends upon pH of the solution and can be negative, positive or neutral.

Lyophobic : The charge on lyophobic sol can be positive or negative.As₂S₃ sol is negative in nature while Fe(OH)₃ sol is positive in nature.

Viscosity

Lyophilic : The lyophilic colloids are highly viscous in nature and have higher viscosity than that of the medium.

Lyophobic : The Lyophobic colloids have almost same viscosity as that of medium.

Reversibility

Lyophilic : Reversible, because on evaporating the liquid, the residue left will passes into colloidal state on addition of liquid.

Lyophobic : Irreversible, because on evaporating the liquid, the residue left cannot be converted into solution on mere addition of liquid.

Electrophoresis

Lyophilic : Depending on the nature of charge these particles may migrate to cathode or anode or may not move at all.

Lyophobic : Depending on the nature of charge these particles migrate to either cathode or anode.

Surface Tension

Lyophilic : The surface tension of these sols is less than that of dispersion medium.

Lyophobic : The surface tension is nearly same as that of dispersion medium.

Cracking IIT just got more exciting,It s not just all about getting assistance from IITians, alongside Target Achievement and Rewards play an important role. ASKIITIANS has it all for you, wherein you get assistance only from IITians for your preparation and win by answering queries in the discussion forums. Reward points 5 + 15 for all those who upload their pic and download the ASKIITIANS Toolbar, just a simple  to download the toolbar….

So start the brain storming…. become a leader with Elite Expert League ASKIITIANS

Thanks

Aman Bansal

Askiitian Expert