Question

What is peptization?

Answer 1

Hint : Deflocculation is the other name for peptization. It is useful in the synthesis of the nanoparticles. It is the opposite of coagulation. Coagulation is the coming together of the particles (which has an opposite charge) to form a clump.

Complete step by step solution :
-Peptization is a process of formation of a colloid from the precipitate with the help of an electrolyte by shaking the solution properly.
-The electrolyte that is used in the process is known as a peptizing agent.
-Some commonly used peptizing agents are sugar, gelatin and electrolyte.
-Firstly, the charge of precipitation is determined then we will use the electrolyte of the same charge because when the electrolyte will be absorbed by the precipitation the particles will bear the same charge.
-It will cause repulsion and hence, the formation of a colloid particle will take place whose size ranges from 1 to 1000 nanometres.
-For example, when we add a small amount of ferric chloride solution to the precipitate ferric hydroxide then it forms a colloid solution which is reddish-brown in colour.
-The chemical reaction showing the action of precipitation is:

$\text{Fe}{{\left( \text{OH} \right)}_{3}}\text{ + FeC}{{\text{l}}_{3}}\text{ }\to \text{ Fe}{{\left( \text{OH} \right)}_{3}}$

-So, here the colloidal solution of ferric hydroxide is formed.

Note : In daily life, we can take the example of clay that is also used in the pottery to make pots. Clay is also obtained by the process of peptization. Peptization is also different from flocculation because flocculation is the process in which the colloids are obtained in a suspension in an aggregate form. That’s why peptization is also known as deflocculation.