Cathodic Protection
Description: Preferential corrosion of zinc rather than iron on a half galvanized nail is revealed by the absence of red iron (III) thiocyanate complex. This is compared to an iron nail in the same solution.
Source: Journal of Chemical Education-Vol. 58
Year: 1981 Vol. 58 Page: 505
Keywords: Zinc, Corrosion, Nail, Iron (III) Thiocyanate, Sacrificial anode
Rating: 
Hazard: Medium
- Acute toxicity hazard – oral, dermal, inhalation
- Aquatic toxicity hazard
- Electric shock hazard
- Skin corrosion hazard
- Serious eye damage
Effectiveness: Average
- Results are observable with guidance
- Mild effects are seen by audience
- Time to results is high – greater than one class period
- System contrast is clear
- Some connection from demo to course material
Difficulty: Low
- Simple procedures
- Manipulations are simple for most to follow
Safety Precautions:
- Eye protection required
- Gloves required
- Use UL approved three-prong plug and outlet
- Absorbent materials on hand
- Perform in a well-ventilated area
- Avoid exposure to mists, droplets and gases
- Prevent release of reagents to the environment
Class: Electrochemistry, Equilibrium, Redox
Division: General, Physical Chemistry
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