Define peptization.

The process of converting a precipitate into a colloidal sol by shaking it with some dispersion medium in the presence of electrolytes is known as peptization. Here, the electrolytes are used as peptizing agent. The stable colloids are formed by using an electrolyte to break up a precipitate and disperse it into the colloid.

When ferric chloride is added to ferric hydroxide precipitate, the precipitate of hydroxide changes to sol by adsorbing ferric ions. Fe³⁺ gets adsorbed on Fe(OH)₃ and breaks into colloid.