Boltzmann: Digital Simulation of Digital Molecular Theory
Flow of Gases Through a Porous Cup
Rate of Diffusion: The Ammonium Chloride Ring
Digital Molecular Theory Simulator
Explosive Reaction of Hydrogen and Oxygen
Kinetics of Oxidation of Iodide Ion by Peroxide
Catalytic Decomposition of Hydrogen Peroxide
Potentiometry with the Belousov-Zhabotinsky Reaction
Potentiometry With the Briggs-Rauscher Reaction
Studying Enzyme Kinetics Using Catalase
Transport of Carbon Dioxide Through a Soap Film
Boiling Acetone at Reduced Pressure
Flow of Gases Through a Porous Cup
Description: When a porous cup is immersed in air, no net gas flow occurs. When immersed in a gas lighter than air, a net inflow occurs. The rate of diffusion into the device depends on the molar mass of gas. When immersed in a gas heavier than air, net outflow of gas is observed.
This demonstration is also available on video and JCE Software “Chemistry Comes Alive!” CD-ROM Vol. 1
Source: Shakhashiri, B.Z. “Chemical Demonstrations: A Handbook for Teachers”
Year: 1985 Vol: 2 Page: 54
Keywords: Diffusion, Porous Cup, Kinetic Molecular Theory, Molecular speeds
Rating: 
Hazard: Low
- Use of inert materials
- Breakage hazard
- Asphyxiation hazard
Effectiveness: Good
- Good connection from demo to course material
- Clear contrast between behavior of systems
- Mild effects are seen by audience
- Time to results is low
- Moderate reliability
- Results are observable with guidance
Difficulty: Medium
- Some sequential manipulations
- Precise manipulations are required
- Some intermediate steps to results
- Use of pressurized gas
Safety Precautions:
- Eye protection required
- Perform in a well ventilated area
Class: Gases, Kinetics
Division: General, Physical Chemistry
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