Electrolysis of Water
Description: A Hoffman apparatus is used to electrolyze water (with some potassium sulfate added to increase conductivity). The gases rise in separate containers, and their volume ratio is 2:1. The gases can be combined and ignited after electrolysis.
Source: Shakhashiri, B.Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry
Year: 1992 Vol: 4 Page: 157
Keywords: Hoffman apparatus, Electrolysis, Stoichiometry, Water, Current
Rating: 
Hazard: Some
- Electrocution hazard
- Flammability hazard
- Flammable gas-producing reaction
- Explosion hazard
Effectiveness: Average
- Good connection from demo to course material
- Results are observable with guidance
- Mild effects are seen by audience
- Good reliability
- Time to results is high
Difficulty: Medium
- Some intermediate steps to results
- Manipulations are simple for most to perform
- Scientific glassware in use
- Sequential or timed manipulations
- Prior training recommended
Safety Precautions:
- Eye protection required
- Perform in a well-ventilated area
- Use of UL approved three-prong plug and outlet
- ABC fire extinguisher on hand
- Use caution when handling flammable gas
Class: Electrochemistry, Electrolysis, Acids and Bases
Division: General, Analytical Chemistry, Physical Chemistry
A different version of the demonstration Electrolysis of Water may be found under Electrochemistry- Electrolysis of Water.
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