Science
What is Electrolysis?
Electrolysis is using an electric current to drive a chemical reaction that wouldn't happen on its own — usually to split a compound apart. Passing electricity through water, for example, breaks it into hydrogen and oxygen gas.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains electrolysis.
Key things to understand
- 1An electric current is passed through a liquid or molten compound.
- 2It forces a reaction, pulling the compound apart.
- 3Splitting water yields hydrogen and oxygen.
- 4It's used to purify metals and to electroplate objects.
- 5It's essentially a battery's chemistry run in reverse.
Frequently asked questions
- What is electrolysis used for?
- Splitting water for hydrogen fuel, extracting and purifying metals like aluminum, and electroplating items with a thin metal coating.
- How does electrolysis split water?
- The current pulls water molecules apart at two electrodes, releasing hydrogen gas at one and oxygen at the other.
- Is electrolysis the opposite of a battery?
- In a sense — a battery uses a chemical reaction to make electricity, while electrolysis uses electricity to force a chemical reaction.