2Precautions Follow all lab safety rules Wear goggles and aprons Make sure your penny is clean and shinyZinc chloride is corrosive if it falls on your skin – inform the instructor and wash under cold waterDo not allow the zinc chloride solution to boil
3PrecautionsGranulated zinc is combustible do not add water to it follow teacher instruction to dispose offUse forceps to put and remove pennies from the beaker . Do not drop them in beakerUse tongs to hold the hot beakerrinse the zinc treated penny in in water and pat dry with a paper towelHeat gently on the hot plate over heating will result in penny changing back to a copper colorfollow teacher instructions for disposal of zinc chloride and zincwash hands
5Obtain 3 pre 1982 penniesUse vinegar and salt mixture to clean the pennies followed by cleaning them with steel wool
6Preparation of "Gold" Pennies Part 2Procedure1. Place ~1 g of granular zinc in an beaker dish on a hot plate.2. Add ~ 10 ml of 1 M zinc chloride and cover with a watch glass.3. Bring the solution to a gentle bubbling not boiling .4. Add a penny, cover and simmer until the penny becomes silvery. Stir it occasionally.5. Use tongs to remove the penny from the evaporating dish and rinse it with water.Part 3Rinse in water and pat dry6. GENTLY heat the penny in a hot plate until it turns to gold. forth while heating. You can ruin your penny by overheating it.7. Drop the penny in a beaker of water. Remove the penny from the beaker and dry.
7Post penniesTo conserve copper and reduce costs, the penny has been made of 97.5%zinc and 2.5% copper,
10An alloyAn alloy is a material that contains more than one element and has the characteristic properties of metals.primary ways of modifying the properties of pure metallic elements.As an example, pure gold is extremely soft to use to make jewelry-14 karat gold – an alloy meaning that it is 58 percent gold