Question

) Coagulation is the just reverse of

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Answer 1

Answer:

The colloidal sols are stable by the presence of electric charges on the colloidal particles. It is because of the electric repulsion, the particles do not come close to one another and coalesce. The removal of charge by any means will lead to the aggregation of particles and hence, precipitation immediately. The process by means of which the particles of the dispersed phase in a sol are precipitated is known as coagulation or flocculation.

The process of bringing a precipitated substance back into the colloids state is known as peptization. It is carried out by the addition of an electrolyte. The electrolyte added is termed as peptising or dispersing agent. It involves the adsorption of a suitable ion supplied by the electrolyte added by the particles of the precipitate.

Answer 2

Coagulation is just the reverse of peptization.

• It is also alternatively termed as flocculation.

• Peptization is referred to as the process of conversion of a precipitate into colloidal solution with the help of a dispersion medium and electrolyte.

• The electrolyte, in this case, is referred to as the peptizing agent as it helps in breaking up of the precipitate into colloids.

Example:

Addition of ferric chloride to the precipitate of ferric hydroxide.

The precipitate absorbs ferric ions, thereby leading to the breaking up of the precipitate into colloids.