Question

In Bredig's arc method, an electric arc is struck 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

Answer: (C)

both dispersion and condensation

In Bredig's arc method, an electric arc is struck between electrodes of the metal immersed in the dispersion medium. The intense heat produced vapourises the metal, which then condenses to form particles of colloidal size.

This process involves dispersion as well as condensation.

Colloidal sols of metals such as gold, silver, platinum, etc., are prepared by this method.

Hence, the correct answer is option $\text{C}$.