"Alchemist's gold" experiment
How to turn copper coin gold
In this simple and amazing experiment, we teach you how to make “gold” coatings!
Reagents and equipment:
- solution of zinc sulfate (20 g in 50 ml of water);
- distilled water;
- copper coin;
- candles or dry fuel;
- burner for dry fuel;
Pour the solution of zinc sulfate into the glass. Add zinc granules. Place the copper coins in the glass so that they touch the zinc. Heat the glass. Take the “silver” coins out of the glass and heat them over the burner. They become “golden”.
When heated, zinc gives up its electrons to copper. Copper becomes negatively charged, and attracts the zinc ions in the solution to its surface. Zinc is reduced on the surface of the copper, and the coin seems to turn silver. If the coin is heated, it becomes “golden”. This is because on heating, diffusion from copper to zinc takes place, and an alloy of copper and zinc is formed, which has a “golden” color. If the coin is immersed in cold water, the color becomes richer.
After the experiment, wash your hands thoroughly with soap. Observe safety rules in working with flames and heating devices.