Boyle’s Law and the Monster Marshmallow
Description: Place a marshmallow inside a bell-jar, and evacuate it. The marshmallow swells as the external pressure is reduced.
Source: Journal of Chemical Education Vol. 59
Year: 1982 Vol: 59 Page: 974
Keywords: Boyle’s Law, Marshmallow, Pressure, Bell jar, Vacuum
Rating: 
Hazard: Some
- Implosion hazard
- Electric shock hazard
- Rotating machinery in use
Effectiveness: Good
- Results are clearly observable without guidance
- Time to results is medium
- Clear contrast between behavior of systems
- Good connection from demo to course material
- Moderate failure rate – fresh marshmallow required for performance
Difficulty: Medium
- Some concerted or timed manipulations
- Demos at non-standard conditions
- Manipulation of large glassware
- Some sequential steps to results
Safety Precautions:
- Eye protection required
- Use of UL approved three-prong plug and outlet
- Lab coat recommended
- Handle large glassware with care
Class: Gas Laws, Physical Chemistry
Division: General
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