Optical Extinction
Description: Glass beads are added to a crystallizing dish placed on an overhead projector. As more beads collect in the dish, more light is blocked by the beads. The beads are added until almost all the light is blocked. Adding toluene to the dish restores the transmission of light through the beads. This experiment is available on video.
Source: Professor Hyuk Yu, 2012
Year: 2012 Vol: N/A Page: N/A
Keywords: Toluene, Glass Beads, Scattering, Diffraction, Absorption, Transmission
Rating: 
Hazard: Medium
- Reproductive Toxicity
- Flammability
- Long and short term aquatic toxicity
- Specific organ toxicity- CNS
- Aspiration hazard
- Skin irritation
Effectiveness: Good
- Some connection from demo to course material
- Excellent reliability
- Time to results is low
- Clearly observable without guidance
- Mild effects are observed
Difficulty: High
- Some sequential manipulations required
- Use of toxic reagents
- Prior practice recommended
- Use of electricity
- Use of flammable reagents
Safety Precautions:
- Eye protection and gloves required
- Use of UL approved three-prong plug and outlet
- Perform in a well-ventilated area
- Avoid exposure to mists, droplets, and liquids
- Avoid release to the environment
Class: Physical Properties of Substances
Division: Physical Chemistry