[lawrencelaptop]

Need help! God knows why, but when trying to electrolysise sodium chloride solution I can only ever produce hydrogen from the cathode, and brown malleable metal chips and a blue swirling cloud in the solution from the anode. I can only assume that the bubbles at the cathode are hydrogen (cant do s-p test cause I'm not producing enough) and that the flakes or brown are pieces of copper chloride.
I need gaseous chlorine though!

Please help!

[DrP]

Pretty sure you wont get Cl like this. The Salt can't be in solution and needs to be molten to do electrolysis with it. However - this isn't possible with your home set up as it would be too dangerous.

Are there any other ways of Chlorine that you know of?

[lawrencelaptop]

DrP said:

Pretty sure you wont get Cl like this. The Salt can't be in solution and needs to be molten to do electrolysis with it. However - this isn't possible with your home set up as it would be too dangerous.

Are there any other ways of Chlorine that you know of?

No i know this is possible- a solution would allow the ions to carry charge, thereby allowing chlorine to be released at the anode when it ditches electrons. The chlorine then bonds with another chlorine particle to become Cl(2), which in other words is gaseous Chlorine.

This is because the Chlorine wins out against the hydroxide due to its much greater reactivity.

Still dont get how its not producing chlorine gas either? BTW, on the off hand safety is not a concern- the hydrogen I am containing safely and I have a chemical mask, googles and an apron to combat harmful chemicals and the inhalation of toxic chlorine.:cool: Molten is not a problem either, seeing as i know for a cert that doing this with brine is possible.

[Fuzzwood]

By the looks of it, you are using a voltage that is way too high. It's like boiling off 100 ml of ethanol with an industrial heater.

[lawrencelaptop]

What effect would the voltage have on the production of chlorine gas? Just wondering, cause I have used about 20 in this assuming it would only affect the speed of the production of chlorine gas. Actually, now I come to think of it I did try a nine volt battery but that didn't work either :S

[Mr Skeptic]

I'm pretty sure that if you mix sodium hydroxide with chlorine the chlorine is going to react with the sodium. So, any Na you get reacts with the water immediately to form NaOH, and if you did manage to form Cl, it would react with that and you're back where you started. Meanwhile, the H2O is much easier to split apart.

[lawrencelaptop]

Mr Skeptic said:

I'm pretty sure that if you mix sodium hydroxide with chlorine the chlorine is going to react with the sodium. So, any Na you get reacts with the water immediately to form NaOH, and if you did manage to form Cl, it would react with that and you're back where you started. Meanwhile, the H2O is much easier to split apart.

Yet I've succeeded in bubbling off chlorine gas before in class? I genuinely don't understand where this is going wrong :S

[TheJames]

The sodium made will react with the water to form sodium hydroxide.
The hydrogen will just bubble up on the cathode
At the anode you'll get oxygen and chlorine.

I suggest you try this in
Water and sodium chloride mix with graphite electrodes (just break open a pencil)

[Justonium]

It's the electrode. It's getting oxidized instead of the chloride ions in the solution. To oxidize these, you will need a non reactive electrode. Try graphite. Also, as you're cell runs, chlorine production will soon stop, as the solution becomes more basic. You will then be making hypochlorite ions instead. To prevent this, you need to separate the solutions by the anode and by the cathode. You can complete the circuit easily enough with a salt bridge--a sliced hotdog or a cloth soaked in electrolyte will work OK.

[Cropduster23]

I would suggest mixing hydrogen peroxide with toilet bowl cleaner. That will make lots of chlorine. I think.

[Leader Bee]

Yes, bleach tends to have a lot of chlorine in it.

What about alcohol & liquid chlorine?

This post has been edited by Leader Bee: 8 July 2010 - 03:58 PM

[Mr Skeptic]

Cropduster23 said:

I would suggest mixing hydrogen peroxide with toilet bowl cleaner. That will make lots of chlorine. I think.

I would suggest not breathing chlorine since it can and will kill you.

[missgeek]

use brine, 12v and carbon electrodes. if doing it by electrolysis.

if not and you need a lot of chlorine use potassium permanganate and hydrochloric acid as strong as you can get. brick cleaner has a high percentage of hcl.

you need to produce it in a safe place with adequet ventilation i.e a fume cupboard as the slightest bit in your nose could hospitalize you