Turn pennies silver and gold using zinc sulfate and zinc
name: Displacement of zinc from the supersaturated solution by copper
Turn Pennies Silver and Gold (Chemistry Trick)
Делаем из медной монеты золотую (химия)
Quick Lab: Alloys Gold/Silver/Bronze Pennies (Demo,theory,equations)
by Richard Thornley
Penny Chemistry Tricks
Превращаем медную монету в золотую (Химия).wmv
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Always follow general safety
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Zn + Cu → Zn2+ + Cu2-
Cu2- + ZnSO4 → Cu + Zn + SO42-
Zn2+ +SO42- → ZnSO4
- Stage 1. Making a coin silver. Dissolve 30 grams of zinc sulfate in 100 ml water in a beaker.
- To speed up dissolution, place the beaker on a hot plate.
- Place a little amount of metallic zinc in the beaker
- Put the copper coin into the beaker using tweezers so that it touches the zinc.
- Heat the solution until it starts to boil Get the boiling solution. Boil for 10 minutes.. Boil for 10 minutes.
- Remove the coin from the solution using tweezers, rinse and dry it.
- Stage 2. Making a gold coin Place the "silver" coin on a hot plate, heated to 570 ° F (300 ° C)
- After the coin becomes a golden color, remove it using tweezers from the hot plate and cool it down.
Zinc gives away its ions and the solution overflows with zinc ions. Copper is less electronegative metal. It attracts more electronegative zinc ions. The copper coin gets covered with a thin layer of zinc. When the "silver" coin is heated, zinc diffuses in the copper coin. Color mixing gives gold.