Question

Colloidal solutions of metals like gold can be prepared when their salt solutions react with certain substance like formaldehyde, phenyl hydrazine, etc.

$2 \mathrm { AuCl } _ { 3 } + 3 \mathrm { SnCl } _ { 2 } \rightarrow 3 \mathrm { SnCl } _ { 4 } + 2 \mathrm { Aol}$

The above method is an example of

• A. (a) Reductions method
• A. (b) Oxidations method
• A. (c) Hydrolysis method
• A. (d) Double decompositions method

Answer 1

(a)

Sol. Salt solutions of gold is being reduced to gold by using a recuing agent like