Cleaning products at home

Step 2 Activity:
Clean you silverware

Description and purpose of the activity

In this activity we use foods which can be found in every home, in order to tarnish a silver or silver-plated object quickly. Then a very simple cleaning method is described where aluminum foil is used to remove tarnish, bringing the object back to its prior condition. The purpose of this activity is to relate the use of chemistry to everyday objects, to perceive the chemical reactions causing silver or silver-plated objects to tarnish and to comprehend chemical reactions’ reversibility.

Apparatus

• 1 glass bowl
• 1 teaspoon
• 1 measuring cup
• 1 towel
• 1 stirring rod
• Microwave or hot-plate

Ingredients - Materials

• 1 silver or silver-plated item (silver-plated knife, silver ring or silver bracelet)
• Baking soda
• Aluminum foil
• Water
• Mayonnaise or mustard or hard-boiled egg

Procedure

1. Take an untarnished silver or silver-plated object, like a knife or a ring, and a material which contains sulfur compounds, like mayonnaise.
2. Coat the handle of the knife, or part of the silver object, with mayonnaise and leave overnight, in order to allow the chemical reaction (tarnish) to be completed. If the object is not tarnished enough we can leave it coated for a second night.
3. Put ¾ cup of water into a glass bowl and heat the water to boiling in a microwave.
4. When it boils add slowly 1/2 teaspoon of baking soda and stir.
5. Clean the knife well from the mayonnaise and wrap half of the tarnished surface with aluminum foil, leaving the rest exposed.
6. Place the knife into the bowl in a way that the whole tarnished surface (covered or not) is submerged.
7. Wait 20 minutes. Remove the knife from the bowl. Remove the aluminum foil. You will observe that the surface covered with the aluminum foil has been cleaned up and you will notice an odor coming from the foil. Hydrogen sulfide is responsible for this odor This is the same odor emerging from a rotten egg.