Question

Bredig’s arc method involves:
a.) Dispersion
b.) Condensation
c.) Peptization
d.) Dispersion and condensation both

Answer 1

Hint: Bredig's arc method is basically a method of preparation of colloidal solution, of metals such as gold, silver or platinum. Bredig's arc method is a method of preparation of colloidal solutions of metals such as gold, silver or platinum. This method consists of both dispersion and condensation.


Complete step by step answer:
In Bredig's arc method, an electric arc is struck between electrodes of the metal immersed in the dispersion medium and the intense heat that is produced by the virtue of it, vaporizes the metal, which then condenses to form particles of the size of colloidal ones.
So, the correct answer is “Option D”.

Note: One must remember that though Bredig’s arc method involves preparation of colloidal solution of metals but, however, colloidal solution of Fe cannot be obtained by the same method since Fe doesn’t react with alkalis.
Hence option A (Dispersion), B (Condensation) and C (Peptization) are incorrect and option A (Dispersion) is correct.