Brass Penny Lab
BACKGROUND: Alloys are mixtures of metals. The metals are not chemically bonded. They are simply mixed together like salt and pepper. Examples of alloys would be bronze (copper and tin), stainless steel (Iron, chromium, and nickel), solder (tin and lead), and 14 karat gold ( gold and copper). Today you will make an alloy called brass. Brass is a combination of copper & zinc. Pennies are made from copper.
- bunsen burner
- concentrated sodium hydroxide
- ring stand
- zinc metal powder
- small beaker
- pennies (shiny new)
- hot plate
- Put your goggles on. Get concentrated sodium hydroxide and zinc from teacher.
- Mix together and heat mixture. Do NOT let it boil and do NOT put your face close to beaker.
- Place 2-3 pennies in heated mixture.
- After 3-5 minutes, use tweezers to remove the pennies. Place the pennies on a wooden block and rinse and clean them. They should be a silver color. If not, return them to the heated mixture.
- Pick up one of the pennies with tweezers and carefully pass the penny through a bunsen burner flame flipping it over several times until it takes on a brass color. Place it in a stream of water and put it on a wooden block to cool. DO NOT OVERHEAT THE PENNY.
- If time permits, repeat steps #3-5.
- Brass is an _________ made of _____________ and _____________
- Where did the two elements (________&__________)needed to make brass come from__________________________________________________?
- Brass and other alloys are ________________ of metals.
- What did the flame do to make the zinc covered penny change to brass?