Question

Colloidal gold can be prepared by:

• A. bredig's arc method
• B. reduction of $AuC{l}_3$
• C. hydrolysis
• D. peptization

Answer 1

Answer: (A), (B)

The correct options are
A bredig's arc method
B reduction of $AuC{l}_3$

Reduction of $AuC{l}_3$ :
Colloidal solutions of metals like gold, silver and platinum can be obtained by reduction of their salts.

$2AuC{l}_3+3SnC{l}_2\to 3SnC{l}_4+2Au$.

Bredig's arc method:
This method is suitable for preparation of colloidal solutions of metals like gold, silver, platinum etc.
Hydrolysis: for iron
Peptization: for Fe, Ag, Sn and Cd.