Question

In Bredig’s arc method, an electric arc is stuck between the metal electrodes under the surface of water containing some stabilizing agent. The process involves:

(a) Mechanical dispersion
(b) Condensation
(c) Both dispersion and condensation
(d) Ultrasonic dispersion

Answer 1

Hint :Bredig’s arc method is a method which is used for the preparation of the colloidal solutions of metals. The metals such as Gold, silver and Platinum are suitable for the preparation of the colloidal solution with the help of Bredig’s arc method.

Complete Step By Step Answer:
First of all, we will discuss what is Bredig’s arc method:
Bredig’s arc method: Bredig’s arc method is a method which is used for the preparation of the colloidal solutions of metals. The metals such as Gold, silver and Platinum are suitable for the preparation of the colloidal solution with the help of Bredig’s arc method.
Now, we will discuss how we prepare sols from Bredig’s arc method:
Bredig’s arc method consists of two processes. They are dispersion and condensation, in which an electric arc is struck between the electrodes under the surface of water which contains some stabilizing agents. When intense heat is applied in them, the arc vaporises the metal which condensed under the cold water and then colloidal particles are prepared in the stabilised by adding some amount of potassium hydroxide.
So, from the above discussions we can conclude that in the Bredig’s arc method, an electric arc is stuck between the metal electrodes under the surface of water containing some stabilizing agent, in these the process there are of both dispersion and condensation.
Hence, the correct option is (c) Both dispersion and condensation.

Note :
Although Bredig’s arc method is a method which is used for the preparation of the colloidal solutions of metals, it is not suitable to prepare a colloidal solution of copper and sodium and also when the dispersion medium is an organic liquid as considerable stirring occurs.