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?