Question

A metal article is to be electroplated with silver. The electrolyte selected is sodium argentocyanide.

1. What kind of salt is sodium argentocyanide?
2. Why is it preferred to silver nitrate as an electrolyte?
3. State one condition to ensure that the deposit is smooth, firm and long lasting.
4. Write the reaction taking place at the cathode.
5. Write the reaction taking place at the anode.
   

Answer 1

1. It is a complex salt.
2. Sodium argentocyanide is preferred over silver nitrate because it gives a smooth and firm silver plating over the article.
3. If silver nitrate is used, then the deposition of silver will be fast and not smooth.
4. Reaction at Cathode:
   \[\ce{Ag+ + e- -> Ag}\]
5. Reaction at Anode: 
   \[\ce{Ag − e- -> Ag+}\]