Introduction: Make Copper Powder From Aluminum Foil

By ChemTalk Website
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Today we are going to turn aluminum foil into copper powder. Yes, pure elemental copper. This is going to be fun!

Follow the instructions, or watch the helpful video above!

Supplies

Copper Sulfate (Root Killer) - found at any hardware store

Aluminum Foil

Glass Jar (16 ounce jar is best)

Coffee Filter

Table Salt

Funnel (optional)

Gloves: latex, vinyl or nitrile (optional)

Step 1: Dissolve Copper Sulfate in a Cup of Water

Dissolve one ounce (28 grams) of blue crystals of copper sulfate in one cup (250ml) of warm water in a clear jar. You may have to stir it for several minutes.

Copper sulfate is somewhat toxic, so don't touch it, drink it, or pour it on yourself. And definitely don't splash it into your eyes. We suggest wearing gloves and googles to be on the safe side.

If you do touch the solution or crystals, don't panic, just wash your hands. It is not anywhere close to be at the same level of a poison as say, arsenic or cyanide - or even many household cleaners.

Step 2: Add Aluminum Foil Into the Solution

Add about 3 grams of aluminum foil, that's two 4 x 4 inch squares.

Step 3: Watch Nothing Happen

Watch the aluminum foil for 30 seconds. You will see nothing happening.

This is because, aluminum foil (and all aluminum metal) has a layer covering it that makes it non-reactive. This layer is so microscopically thin, it is not visible to the eye.

Step 4: Add a Pinch of Salt

About a 1/4 teaspoon of salt is all you need to add. This will allow the aluminum foil to react with the solution.

Science Explanation: The chloride ions from the salt will allow the copper (II) ions to bypass the 50 nanometer thin passivation layer of aluminum oxide on the aluminum foil. They then react with the aluminum metal.

You may see some bubbles appear. This is hydrogen gas being formed. A small amount of the aluminum reacts directly with water to form hydrogen gas. Also, it is normal for the solution to become quite warm.

Step 5: Watch the Copper Appear

The aluminum foil will slowly turn into copper. You made an element!

This will take 30-60 minutes to complete. All of the aluminum foil should disappear, and the solution should turn from blue to clear. If the foil is gone and the solution is still blue, add a little more aluminum foil.

The copper powder should fall to the bottom. If there is foil floating at the top with copper attached to it, whack the piece of foil with an object to dislodge the copper, and it should fall to the bottom.

Once the solution is fairly clear, it is fairly non-toxic and does contain any more copper ions. Still, I would not drink it.

For all you chemistry nerds, here is the reaction: 2Al + 3CuSO4 → Al2(SO4)3 + 3Cu

Step 6: Filter and Dry Your Copper Powder

Remove any bits of aluminum foil that are left in the jar with tweezers. Then, dump the solution and the copper powder into a coffee filter. If you have a funnel that the coffee filter will fit in, now is the time to use it.

After the liquid goes through the filter, wash the copper powder with a small amount of water while it is still in the filter. Then dry it, and store it or admire it! You can even melt it down into an ingot.

The clear liquid that remains after you filter the copper powder contains aluminum sulfate. If you let the water evaporate, you will have nice crystals of aluminum sulfate. They are usually white, but they may look slightly greenish due to iron impurities that came from the aluminum foil, because foil usually contains 1% Iron.

Time to celebrate! Let the ChemTalk team at chemistrytalk.org know if you enjoyed the experiment

LAST STEP

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