[poor mystic]

A member of an electronics forum posted that he has electrolysed salty water using 19V and steel electrodes. He states that the water turns green, and that chlorine gas is evolved. He asks for comments, some of which have been more interesting than others.

My own thought is that this might produce sodium hypochlorite (NaOCl) bleach. Can anybody confirm whether this is so?

[AWK]

Both: chlorine and hypochlorite react with iron, at least partially.

[poor mystic]

Thanks AWK.
Say he were to use carbon electrodes, would sodium hypochlorite be produced?

[vmelkon]

yup, the Cl2 tends to dissolve in the water and react with the NaOH. I'm not exaclty sure of the equation but hypochlorite gets produced.
http://www.youtube.com/watch?v=6WwytVbSKUI

[AWK]

Thanks AWK.
Say he were to use carbon electrodes, would sodium hypochlorite be produced?

You should allow to mix solutions close to both electrodes and control temperature (as low as possible) to avoid disproportionation to higher chlorates

[Denu]

So the dissolved chlorine is what turns the colour of the solution green, right? I did the same thing about a year ago, and got similar results to the person posting this. I was in O levels back then, so I didn't know anything about sodium hypchlorate.

[poor mystic]

it sounds like this might be the usual way that chlorates are produced? I wonder how the reaction would be optimised for chlorates anyway. I can't see them precipitating. Maybe by putting the electrodes close together and shoving current through as fast as possible..
What a complex subject salty water electrolysis is! It must have been very difficult for the early chemists... I knew that already but it is really coming into focus now.

[Borek]

So the dissolved chlorine is what turns the colour of the solution green, right?

No. There is not enough chlorine to color the solution. Observed green is most likely product of electrode material oxidation.