Peptization is a process of :

Options

A. in which colloidal particles move in an electric field.
B. of purification of colloids
C. of precipitation of colloidal particles
D. of dispersing precipitates into colloidal sols

Answer

D

Explanation

Peptization is the process of converting a precipitate into colloidal sol by shaking it with dispersion medium in the presence of a small amount of electrolyte.
The electrolyte used for this purpose is called peptizing agent. This method is generally applied to convert a freshly prepared precipitate into a colloidal sol.
During peptization, the precipitate adsorbs one of the inos of the electrolyte on its surface. The ions adsobed on the surface is common either with the anion or cation of the precipitate. This cause the develoment of positive or negative charge on precipitates which ultimately break up (on account of repulsion) into smaller particles having the dimensions of colloids. For example, when freshly precipitated, `Fe(OH)_(3)` , it adsorbs ferric `(Fe^(3+))` ions and thereby breakes up into small-sized particles.