[horsebox]

If my knowledge is correct when you run current through a NaCl solution chlorine gets freed up leaving a surplus of sodium cations. The sodium will obviously react with the water and form NaOH. I read on a chemistry forum a thread talking about procuring NaOH like this using graphite from pencils as the electrodes. NaOH is cheap and easy to get a hold of but this is still a fairly cool experiment. Wouldn't mind trying it myself. Has anyone here tried this?

[Schrödinger]

not tried, but this is the basis of the chlor-alkali industry.

chlor = Cl₂
alkali = NaOH

[Borek]

The sodium will obviously react with the water and form NaOH.

That's not exactly true, although the idea (that sodium would react with water) is correct. But in reality it is water that reacts on the electrode producing hydrogen, sodium is not being reduced in water solutions.

[billnotgatez]

Borek -

is not the results
hydrogen
Chlorine
Sodium hydroxide

[Borek]

Yes, I was refering only to the cathode reaction.

[Doctor science]

If my knowledge is correct when you run current through a Na Cl solution chlorine gets freed up leaving a surplus of sodium cations. The sodium will obviously react with the water and form Noah. I read on a chemistry forum a thread talking about procuring Noah like this using graphite from pencils as the electrodes. Noah is cheap and easy to get a hold of but this is still a fairly cool experiment. Wouldn't mind trying it myself. Has anyone here tried this?

yes i have the aquas solution of table salt will turn green due to the concentration of chlorine if you are using copper to do the experiment. ( heads up... do this experiment in a well ventilated area because I inhaled the chlorine gas and it annoyed me biologically....(burning nose membrane)

[Borek]

yes i have the aquas solution of table salt will turn green due to the concentration of chlorine if you are using copper to do the experiment.

Pure nonsense. Concentration of chlorine doesn't depend on the copper presence, and color of the solution has nothing to do with the chlorine.

[MrTeo]

I tried it once with graphite electrodes (personally I didn't use sharp pencils, but graphite sticks for mechanical pencils with a ∅ of 1 or 2mm) and I din't notice any changement in the solution's colour. Anyway NaOH isn't the only product as Cl₂ reacts with OH^- giving ClO^-:

Cl₂+OH^-→Cl^-+ClO^-+H₂O

That's why if you sniff next to the solution's surface during the process you'll perceive the characteristic smell of bleach (due to ClO^-)