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Growing Copper Crystals (continued)
Background Knowledge:
When different types of matter interact, they may undergo physical or chemical changes. A physical change can be observed
without changing the composition of the matter. A chemical change, or reaction, occurs when two or more substances combine
to form a new substance with new properties. Some signs that a chemical reaction has occurred include formation of gas, odor, or
precipitate, unexpected color or temperature changes,combustion, and oxidation (rusting). There are different types of chemical
reactions based on the type of matter involved and the type of new substance that is formed. Some types of reactions are single-
replacement,double-replacement, combination, and decomposition reactions. Many elements on the periodic table are classified
as metals. Some identifying properties of metals are their high luster, good conductivity, ductility, malleability, higher density and
melting points. Metals are also classified as being crystalline solids, meaning its atomic structure is arranged in a set pattern, and it
has a specific melting point. Many metals are highly reactive, where others are not.
Materials:
• Preform with cap, or oversized test tube, 40ml, with cap
• Preform rack or something to hold it upright
• 500G Copper II sulfate pentahydrate, medium crystals, lab grade
• Salt (non-iodized preferable)
• Bright finish common iron nails, 2 ½ or 3" length
• Steel wool
• Cotton round pads or filter paper
• Water (distilled preferable)
• Scissors
• Pen/pencil or stirring rod to use as a "poker"
Step-by-step Procedure:
1. Use the steel wool to clean the bottom half surface of 2 or 3 nails; set them aside.
2. Cut 2 circles the size of the preform cap from the cotton pads or filter paper; set aside.
3. Add about an inch of copper sulfate crystals into a preform.
4. Add enough water to just cover the copper sulfate crystals, tapping out any air bubbles or gaps to ensure the water is completely
covering all crystals.
5. Pre-soak one of the cut circles, so it doesn't absorb any of the water already added.
6. Use a pen/pencil/rod to lightly pack down the circle barrier layer on top of the crystals.
7. Add about ½ inch of salt, or around 2 teaspoons, into the preform.
8. Add enough water to just cover the salt layer.
9. Pre-soak the other cut circle then lightly pack it down on top of the salt layer.
10. Embed the cleaned nails in the top barrier layer along the side of the tube, crossing over each other to form an
"x" if using 2 nails, or a tripod if using 3.
a. Try not to disturb/displace the barrier layer
b. Pushing the nail into the salt layer will speed up the reaction
11. Add water to the remaining space in the tube to fully cover the nails.
12. Cap the tube and place it upright to make and record initial observations.
13. Make additional observations on day 2, and then several days later as the reaction continues.
