Collapsing Can
Description: A 5-gallon metal can is collapsed under external air pressure either by evacuating the can, or boiling water in it, sealing the can and allowing it to cool.
Description II: Water is boiled in a square can. The can is quickly inverted into a container of water, and the can spontaneously crushes. This demo can also be performed using a vacuum pump to remove air from the can, until atmospheric pressure is sufficient to collapse it.
This demonstration is also available on video and JCE “Chemistry Comes Alive!” Vol. 1 CD-Rom.
Source: Shakhashiri, BZ Chemical Demonstrations: A Handbook for Teachers of Chemistry
Year: 1985 Vol: 2 Page: 6
Keywords: Water, Vacuum, Square can, Pressure, Collapse, Force
Rating: 
Hazard: Some
- Electric shock hazard
- Slip hazard
- Flammability hazard
- Burn hazard
Effectiveness: Good
- Clearly observable without guidance
- Good connection from demo to course material
- Low failure rate
- Time to results is low
- Clear contrast between behavior of systems
Difficulty: Medium
- Simple manipulations for most to perform
- Some intermediate steps to results
- Simple procedures
- Demos at non-standard conditions
Safety Precautions:
- Gloves recommended
- Eye protection required
- Absorbent material on hand
- Flame resistant surface recommended
- Use of UL approved three-prong plug and outlet
Class: Gas Law, Intermolecular Forces
Division: General, Physical Chemistry
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