Old Nassau: The Landolt Reaction with Mercury
Description: Three solutions, when mixed, turn orange and then almost black.
Source: Shakhashiri, B.Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry
Year: 1991 Vol: 4 Page: 29
Keywords: Landolt Reaction, Mercury, Indicator, Clock Reaction, Induction period
Rating: 
Hazard: High
- Acute toxicity hazard – oral
- Aquatic toxicity hazard
- Skin corrosion hazard
- Serious eye damage
- Germ cell mutagenicity hazard
- Reproductive toxicity hazard
- Inhalation hazard
- Specific toxicity hazard – central nervous system
Effectiveness: Good
- Results are clearly observable without guidance
- Good connection from demo to course material
- Time to results is low
- Mild effects are seen by audience
- System contrast is obvious
- Good reliability
Difficulty: Medium
- Adding reagents in concert or timed manner
- Multiple step procedures
- Simple manipulations for most to perform
- Demonstrations in which toxic substances are in use
Safety Precautions:
- Eye protection required
- Gloves required
- Absorbent materials on hand
- Avoid ingestion or inhalation of reagents
- Perform in a well-ventilated area
Class: Kinetics
Division: General
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