Rule 2: Electrolysis and halogens
If the solution on which electrolysis is being performed contains a halogen (such as chlorine and bromine), then the halogen will always form at the anode. If there is no halogen in the solution, then oxygen is formed at the anode.
![Rule 2 - Halogens will form on the anode if no halogens exist in the solution oxygen will form in its place](/images/user/base/Chemistry/11.Electrolysis/2.11.20 Halogens form on the anode image.jpg)
When a solution contains halogens (angels with haloes), they are attracted to the annoyed android (anode) as they want to soothe him and stop him being so annoyed.
Halogen > oxygen > all other negatively-charged ions
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