Explain lyophilic and lyophobic sols with examples. Why do hydrophobic sols get coagulated easily?

Lyophilic sols are colloidal sols that are formed by mixing of substances with a suitable liquid that is dispersion medium. The dispersed phase exhibits an affinity for the dispersion medium

The high affinity is due to the formation of large number of hydrogen bond

Examples: Gum, gelatin and starch

They are reversible in nature. If two constituents of tthe sol are seperated by any means it can be prepared again by mixing dispersion medium with dispersion phase by shaking properly.

Lyophobic sols have no such affinity for the dispersion medium or solvent. They are solvent hating sols. It can be stabilized due to the adsorption of ionsby the dispersed particles.

They are irreversible in nature.

Example Ferric hydroxide or Aluminium Hydroxide dissolved in water

Hydrophobic sols gets easily coagulated because these sols are stabilizes due to the charge on the particle. If the charge is removed byb adding any suitable electrolye the particles tends to

come closer and form aggregate or precipitate.

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