Letter 7447

Why does silver tarnish? 

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Hello, I am in organic chemistry class and today we received a handout asking why and how silver tarnishes. I know it has to do with silver oxiziding, however, I'm not completely sure as to why or how. Does the presence of sulfur, cause the tarnish on the silver?

If anyone could help me I would greatly appreciate it.

C. Benson
- Houston, TX USA

Silver sulfate is the principle product formed when silver turns dark colored (tarnishes). There is sulfur containing compounds in air, and most papers, so to prevent tarnish, one needs to prevent contact of the silvered item with air by storing it in an air tight, sulfur-free container, or, if viewing is desired, applying a tightly adhering clear film such as a lacquer.

W. Carl Erickson
- Rome, New York

Tarnish is what happens to silver when silver becomes silver sulfide. You can see this by looking at silver and looking for a dark black color. This happens when the sulfide in the spoon or metal reacts with the air around it

Amanda D.
- Menomonee Falls, Wisconsin, USA

My silver ring recently turned black,and seeing how I have been wearing it for years without such a reaction I got to wondering what could have caused this. Then I read your reader response on sulfur and realized it must be the sulfur soap I have started using on my face. Lesson learned: Take off your silver jewelry when washing your face with sulfur products!

Panja Cantala
- EL Paso, Texas

Tarnished silver can be cleaned.
With boiling water and baking soda

Rena Kouper
- Christchurch, New Zealand

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