Question

Why is silver cyanide used as an electrolyte in silver plating? (source) There are other (cheaper, less toxic) silver salts, such as silver nitrate. The linked question says that using the nitrate results makes a fairly rough film that can be somewhat easily removed with abrasion. How does the anion affect the adhesion of the film of silver to the cathode? Why does cyanide result in a strong stable layer of silver, but nitrate (or otherwise) does not?

Answer 1

Silver cyanide is used as an electrolyte in silver plating because it forms a strong and stable layer of silver on the cathode. Cyanide ions form strong complex compounds with silver, promoting adhesion of the silver film.

Step-by-step explanation:

Silver cyanide is used as an electrolyte in silver plating because it results in a strong and stable layer of silver on the cathode. The anion, in this case, cyanide, affects the adhesion of the silver film to the cathode surface. Cyanide ions form strong complex compounds with silver, promoting the formation of a smooth and adherent silver layer on the cathode.

On the other hand, silver nitrate, which is a cheaper and less toxic alternative to silver cyanide, does not result in a strong and stable silver layer. The nitrate anion does not form as strong complex compounds with silver as cyanide does, resulting in a rough and less adherent silver film that can be easily removed with abrasion.