What is this reaction? A summary
This reaction between aluminum foil, baking powder, and hot water, removes silver sulfide, or tarnish, from a silver material. This works because there is a chemical reaction between the silver sulfide and the aluminum.
What do we use?
This experiment needs minimal supplies. Its involves a cup of baking powder for every gallon of water, aluminum foil, hot water, a pan large enough to hold the reaction and of course, silver. We are using one ounce of baking powder to every two cups of boiling water.
The Chemical Reaction
The reaction occurs between silver sulfide and aluminum, when they are in contact, while immersed in baking powder. The silver sulfide and aluminum become silver and aluminum sulfide.
3 Ag2S + 2 Al --/> 6 Ag + Al2S3
Chemical Change
This is a chemical change! The silver sulfide becomes silver. The sulfur transfers to the aluminum.
Concept
A chemical change occurs when a new substance is formed through a chemical reaction. This experiment has a chemical reaction that is substitution. You know that there is a chemical reaction because the chemical formula changes. It goes from being 3 Ag2S + 2 Al to being 6 Ag + Al2S3. This means that there is only one compound replacing another, so the chemical reaction is a replacement.
Reaction Procedure
1. Line the bottom of the pan with aluminum foil.
2. Set the silver object on top of the aluminum foil. Make sure the silver touches the aluminum.
3. Heat the water to boiling.
4. Remove it from the heat and place it in a sink.
5. Add one cup of baking powder to each gallon of water. If you need to, change the proportions. The mixture will froth a bit and may spill over; this is why you put it in the sink.
6. Pour the hot baking powder and water mixture into the pan, and completely cover the silver.
Almost immediately, the silver sulfide, or tarnish, starts to disappear. Within a few minutes, there is a noticeable difference in the silver's condition.
Silver Cleaning Chemical Reaction Video
Credits:
Created with images by 422737 - "alu aluminum foil structure" • kboyd - "kettle water boiling" • MichaelGaida - "lost places office broken"