(12-21-2023, 09:15 PM)Stephanos1920 Wrote: Easy way to remove tarnish from copper,
silver,bronze and brass items :
Line the bottom of a Pyrex bowl with aluminium foil ( shiny side facing upwards ).
Add a tablespoon of baking soda and fill with warm water .Stir for the soda to dissolve in water.
Place the object that you want to remove it's tarnish in contact with the aluminium foil.The object should be fully submersed into the water -soda mix.
Watch the magic happening in front of your eyes . Rinse the tarnish-free object with water to avoid soda spots .
Baking soda has an alkaline pH because it contains the bicarbonate ion (HCO3-), which can neutralize acids.
The method you described works for removing tarnish from copper, silver, bronze, and brass items because of a simple chemical reaction known as electrolysis. Here's a breakdown of the steps and the science behind them:
1. Setting the Stage:
Aluminum foil: The shiny side of aluminum foil acts as the anode (positive electrode) in the electrolyte solution. Baking soda and warm water: Baking soda (sodium bicarbonate) is a mild electrolyte. Dissolving it in warm water creates a conductive solution. Tarnished object: This acts as the cathode (negative electrode) in the solution.
2. The Magic Happens:
When the tarnished object comes into contact with the aluminum foil, an electrical current starts flowing between the anode and cathode. This current is generated by the difference in reactivity between the metals involved.
Aluminum is more reactive than most of the common metals used in cookware and jewelry (like copper, silver, bronze, and brass). This means it has a greater tendency to lose electrons and become oxidized. In the electrolyte solution, aluminum ions (Al⁺³) from the foil dissolve and enter the water. Meanwhile, at the cathode (the tarnished object), the aluminum ions gain electrons from the tarnish layer (metal oxides) and convert back into aluminum metal.
3. Tarnish Removal:
As the aluminum ions reduce the metal oxides of the tarnish, they are effectively dissolved back into the water. This removes the tarnish layer and reveals the clean metal underneath.
The baking soda plays a minor role in this process by helping to conduct the electricity and providing some mild cleaning action through its mild alkalinity.
Fun