Electrochemistry Reaction for Cleaning Silver

Introduction

• Demonstration of a simple method to clean silver using electrochemistry.

Materials Needed

• Water (amount depends on container volume)
• Sodium bicarbonate (a couple of teaspoons)
• Aluminum foil
• Piece of silver to be cleaned (e.g., silver spoon)
• Container for the reaction

Steps for Cleaning Silver

1. Prepare Water

   • Heat water in a container.
   • Calculate the amount based on the container volume.

2. Dissolve Sodium Bicarbonate

   • Add sodium bicarbonate to the water and dissolve it.

3. Set Up the Reaction

   • Place aluminum foil in the container.
   • Pour the heated water into the container with aluminum foil.
   • Add the silver piece to be cleaned into the mixture.

4. Electrochemical Reaction

   • An electrochemical reaction occurs between silver sulfide (the tarnish) and aluminum.
   • Sodium bicarbonate acts as the electrolyte (similar to a car battery).

5. Time for Reaction

   • Let the reaction occur for about 10 minutes.
   • After 10 minutes, remove the silver piece and rub it with a paper or cloth.
   • Optionally, repeat for additional brightness.

Explanation of the Reaction

• Cause of Tarnishing: Silver tarnishes due to a reaction with hydrogen sulfide in the air, forming silver sulfide (black substance).
• Reaction Dynamics:
  • Sulfur has a higher affinity for aluminum than for silver, leading to a reduction of silver from silver sulfide and oxidation of aluminum.

Experiment with Silver Spoon

• Repeat the process using a silver spoon that is not as dirty.
• Accelerate the reaction by adding more pieces of aluminum foil and sanding them to enhance the metallic contact.
• Check results after 20 minutes.

Results

• Observe the difference between the reacted and non-reacted parts of the spoon.

Conclusion

• This method effectively cleans silver through an electrochemical reaction.
• Reminder to tune in for the next episode at Cienciabit on Monday.