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Question
Why are hydrophobic sols easily coagulated?
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Solution
The stability of hydrophilic sols depends on two things: the presence of a charge and the solvation of colloidal particles. On the other hand, the stability of hydrophobic sols is only because of the presence of a charge. Therefore, the latter are much less stable than the former. If the charge of hydrophobic sols is removed (by addition of electrolytes), then the particles present in them come closer and form aggregates, leading to precipitation.
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