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
Rate of Diffusion: The Ammonium Chloride Ring
Description: Ammonia gas and hydrogen chloride gas are introduced at opposite ends of a long air-filled glass tube. After about 15-20 minutes, a very localized cloud of white ammonium chloride forms where the two gases meet after diffusing through the air. The location is relative to the molecular masses of two gases.
Source: Shakhashiri, B.Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry
Year: 1985 Vol: 2 Page: 59
Keywords: Diffusion; Graham’s Law, Kinetic Molecular Theory, Molecular speeds, Path length
Rating: 
Hazard: Medium
- Acute toxicity hazard – inhalation, ingestion, oral
- Serious eye damage
- Skin corrosion hazard
- Specific exposure hazard to the eye, lungs
- Aquatic toxicity hazard
- Corrosive to metals
- Spill hazard
Effectiveness: Good
- Good connection from demo to course material
- Some contrast between behavior of systems
- Time to results is high, greater than 20 minutes
- Moderate failure rate
- Results are observable with guidance
Difficulty: Medium
- Some concerted or timed manipulations
- Use of reactive substances
- Simultaneous manipulations
- Demos at non-standard conditions
- Prior training required
- Simple procedures
Safety Precautions:
- Eye protection required
- Gloves required
- Perform in a well-ventilated area
- Chemically resistant surface required
- Downdraft hood recommended
- Absorbent material on hand
- Sodium bicarbonate solution on hand
- Prevent release of reagents to the environment
Class: Gases, Acid-Base Reactions, Kinetics
Division: General, Physical Chemistry
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