Can Ripper
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★☆ Some safety precautions required to perform safely
Categories: Oxidation and Reduction
Alternative titles: Carving a Can with Chemistry, Aluminium vs Copper Chloride
Summary
The inside of an aluminum soda can is scored to break its protective plastic lining. When copper(II) chloride solution is added, a single replacement redox reaction occurs, dissolving the aluminum along the scored line. With only the outer paint layer holding the can together, the can can be ripped apart easily with a twist.
Procedure
- Use a triangular file to carefully score a fine line around the inside of an empty soda can, about halfway down. This exposes the aluminum beneath the protective coating.
- Dissolve about 10 g of copper(II) chloride in 200 mL of warm water. Pour this solution into the can so it covers the scored area.
- Allow the can to sit for 3–5 minutes until the reaction is complete. The aluminum will dissolve along the scored line, visible as darkening paint on the outside.
- Carefully pour out the solution and rinse the can with water.
- Hold the can with both hands on either side of the scoring and twist firmly. The can should rip apart along the weakened line.
Links
Ripping a can in half using science - Imagination Station Toledo:
Can Ripper - Flinn Scientific:
📄 Can Ripper - Flinn Scientific: https://www.flinnsci.com/api/library/Download/0c9afd37a3d54615a049c69f1c80db1a?srsltid=AfmBOor6Mxq8BSucxHMlQrBFZfyGybsk3j_hLRcltRvAo2BVOLfisani
Variations
- Use sodium hydroxide solution instead of copper(II) chloride to remove most of the aluminum, leaving behind only a fragile plastic “can shell.”
Safety Precautions
- Safety goggles must be worn.
- Copper(II) chloride is toxic if ingested and irritating to skin, eyes, and tissues. Avoid all contact.
- Check safety data sheet for sodium hydroxide before using.
- Torn aluminum cans have sharp edges; handle with caution.
- Clearly label solutions and do not leave them where they may be mistaken for drinks.
Questions to Consider
- Why does copper(II) chloride react with aluminum but not the other way around?
- What role does the plastic lining inside the can normally serve?
- How does the activity series of metals explain the outcome of this demonstration?
- What would happen if a less reactive metal salt, such as zinc chloride, were used instead of copper(II) chloride?
- Why is warm water recommended for dissolving copper(II) chloride?