Jae+Kyun+and+Tait

=Golden Pennies=

For our experiment, we have decided to try and make a regular copper penny into a gold plated penny. To do this, we are going to use the materials listed below.

Tait's lab report:

Jae Kyun's Lab Report



Materials

 * Clean Pennies
 * Zinc metal
 * sodium hydroxide (3 molar)
 * tweezers
 * container of water
 * source of heat

Procedure
1. Get a beaker and add a little amount of water into it. 2. Pour in the 3 molar sodium hydroxide solution into the beaker.\ 3. Add zinc powder so that it covers the base of the beaker. 4. Put the beaker on a hot plate and heat it so that it is near boiling. 5. Put the pennies in. ( Add more zinc powder if the pennies are not covered by zinc powder) 6. Wait for 1 or 2 minutes and take the pennies out. 7. Heat them with fire for a few seconds and the colors will start to change. 8. Take the pennies out and cool them.

Images




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=Chemical Reactions=

Copper Penny --> Silver colored Penny The zinc in the hot sodium hydroxide reacts to for soluble sodium zincate (Na2ZnO2). As this touches the surface of the copper coin, it coats it with metallic zinc.

Silver colored Penny --> Gold colored Penny The heat of the fire fuses the zinc and copper to form an alloy. This alloy is called brass. Heating it too much causes the brass to melt and turn brown.