Zinc Dendrites
Synopsis: Aqueous zinc sulfate is added to a Petri dish to just cover the bottom surface of the dish. Graphite and galvanized iron wire electrodes are connected to a 9 VDC battery. After a few minutes, dendritic crystals of Zinc form at the graphite cathode in solution. The crystals propagate toward the galvanized wire anode and will form a “bridge” between the electrodes given enough time.
Zn2+(aq) + 2e− → Zn(s)
ZnSO4(aq) + 2e− → Zn(s) + SO42−(aq)
SO42− (aq)-4e−→ SO2(aq) + O2(g)
Source: Maynard, J.H.
Year: 2023 Vol: N/A Page: N/A
Rating: 
Keywords: Zinc, Dendrites, Electrodes, Electrochemistry, Redox
Hazard: Some
- Acute toxicity – oral
- Serious eye damage
- Short-term (acute) aquatic toxicity
- Long-term (chronic) aquatic toxicity
Effectiveness: Good
- Time to results is low
- Good connection from demo to course material
- Results are observable with guidance
- Clear contrast between systems behavior
- Good reliability
Difficulty: Medium
- Use of scientific equipment
- Some intermediate steps to results
- Demo at non-standard conditions
- Some fine manipulations
Safety Precautions:
- Eye protection required
- Gloves required
- Use UL approved three-prong plug and outlet
- Prevent release of reagents to the environment
- Avoid exposure to dusts, mists, or droplets
Class: Electrochemistry
Division: General
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