Penny into Gold

Demonstrate to your students what the alchemists only dreamed about.  Turn an ordinary copper penny into silver and then into gold.  Students will watch as you place pennies into a chemical solution which turns the pennies silver.  Then over a flame, the silver penny will change into "gold".  

I will first demonstrate how to transmute iron filings into copper metal.  Add a spoonful of CuCl₂ ('magic blue earth') into 50 mL water in a 125 mL Erlenmeyer flask (and swirl to dissolve CuCl₂ salt).  Next, show magnetic properties of iron filings and add a pinch of iron filings into solution of CuCl₂.  Swirl solution and note 'transmutation' of iron into copper.  [Chemical reaction is a single replacement reaction:

                       Fe(s)  +  CuCl₂(aq)  -->  FeCl₂(aq)  +  Cu(s)]

Concepts:  Oxidation-reduction, alloys

Time Required:  15 minutes

Chemicals Provided  Zinc (powdered), sodium hydroxide solution,  

                                      (to clean penny...sodium chloride, vinegar)