Electrolysis of brine produced white stuff.

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Discussion Overview

The discussion revolves around an experiment involving the electrolysis of brine (sodium chloride solution) and the production of hydrogen gas. Participants explore the nature of a white substance that formed during the process and the chemical reactions involved, including the potential formation of sodium hydroxide and other byproducts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Rowan describes an experiment attempting to produce hydrogen using sodium hydroxide, aluminum, and water through electrolysis, noting the formation of a hard white substance around the hydrogen electrode.
  • One participant asks for clarification on the materials being electrolyzed and the electrode composition.
  • Another participant points out that sodium hydroxide and aluminum can react directly to produce hydrogen without the need for electrolysis.
  • There is speculation that Rowan might be trying to produce sodium hydroxide via electrolysis of a sodium chloride solution, which could also produce chlorine at the positive electrode.
  • It is suggested that prolonged electrolysis of a sodium chloride solution could lead to the depletion of chlorine and the formation of sodium hydroxide, with a warning about potential calcium or magnesium hydroxide formation at the negative electrode.
  • Some participants note that both hydroxide ions and hydrogen are produced in the same reaction, indicating a connection between the two processes.

Areas of Agreement / Disagreement

Participants express differing views on the necessity of electrolysis for producing hydrogen from sodium hydroxide and aluminum, and there is no consensus on the identity of the white substance formed during the experiment.

Contextual Notes

There are unresolved assumptions regarding the specific conditions of the electrolysis, the exact composition of the electrolyte, and the potential interactions with the electrodes and sellotape used in the setup.

Who May Find This Useful

This discussion may be of interest to individuals experimenting with electrolysis, those studying chemical reactions involving sodium hydroxide and aluminum, and participants curious about the electrolysis of brine solutions.

Fezziwig
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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.
 
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What were you electrolyzing and what are your electrode materials?
 
Fezziwig said:
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.

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

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.
 
Fezziwig said:
I was seeing whether I could make hydrogen

willem2 said:
I think he's trying to make sodium hydroxide

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

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