Electrolysis of brine produced white stuff.

Fezziwig

As a casual experiment I was seeing whether I could make hydrogen from sodium hydroxide, aluminium and water. Rather than buy sodium hydroxide or go through a load of cleaning products to find it, I thought it would be much more fun to produce it through electrolysis.

I set it up, and the electrolysis was going very well. After about 20 minutes I noticed a small build up of a hard white substance around the sellotape on the hydrogen electrode. Is it sodium hydroxide or is it more likely to be something to do with the sellotape (or indeed somthing else)?

Thanks,
Rowan.

chemisttree

What were you electrolyzing and what are your electrode materials?

Borek

Sodium hydroxide and Al produce hydrogen in a direct reaction, no need for electrolysis.

willem2

I think he's trying to make sodium hydroxide by electrolysis. (Of NaCL?)

Electrolyzing a NaCL solution can produce some chlorine at the positive electrode, and if you keep this up for very long you might lose nearly all of the chlorine and get sodium hydroxide. You probably need to refill the solution many times, and should do this with distilled water, or you might get Calcium and- or Magnesiumhydroxide at the negative electrode.

Borek

Both OH^- and hydrogen are produced in the same reaction. You can't have one without the other.