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Offline legoman600

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electrolosis
« on: 26/10/2007 13:11:19 »


THis is my electrolosis of water with a bit of salt. I used carbon rod electrodes but the ratio of hydrogen to oxgen was about 10:1? CAn anyone help me


 

another_someone

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electrolosis
« Reply #1 on: 26/10/2007 14:36:40 »
Yes - the salt.

You are expecting 2 x H2O -> 2 x H2 + O2

What you are getting is:

2 x NaCl + 2 x H2O -> 2 x NaOH + H2.
 

Offline daveshorts

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electrolosis
« Reply #2 on: 26/10/2007 15:15:06 »
Magnesium sulphate or epsom salts is a really good electrolyte when electrolysing water as both the magnesium and sulphate don't take part in the reaction.
 

Offline DrDick

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electrolosis
« Reply #3 on: 02/11/2007 18:48:36 »
Actually, to completely balance the reaction:

Yes - the salt.

You are expecting 2 x H2O -> 2 x H2 + O2

What you are getting is:

2 x NaCl + 2 x H2O -> 2 x NaOH + H2 + Cl2.

So you still get two gases.  However, Cl2 can then react with aqueous OH- to form hypochlorite and chloride.

Cl2 + 2 OH- → ClO- + Cl- + H2O

Dick
 

Offline techmind

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electrolosis
« Reply #4 on: 02/11/2007 21:28:47 »
I trust that after doing the electrolysis you're mixing the gas-contents of the tubes and then putting a match to them... for a very satisfying "pop"  :)
 

Offline daveshorts

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electrolosis
« Reply #5 on: 03/11/2007 10:52:35 »
I once managed to fire a ping pong ball 4 stories vertically by doing this - was quite loud...
 

another_someone

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electrolosis
« Reply #6 on: 03/11/2007 11:14:22 »
Actually, to completely balance the reaction:

Yes - the salt.

You are expecting 2 x H2O -> 2 x H2 + O2

What you are getting is:

2 x NaCl + 2 x H2O -> 2 x NaOH + H2 + Cl2.

So you still get two gases.  However, Cl2 can then react with aqueous OH- to form hypochlorite and chloride.

Cl2 + 2 OH- → ClO- + Cl- + H2O

Dick

Sorry, I should have spotted the missing Cl.
 

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electrolosis
« Reply #6 on: 03/11/2007 11:14:22 »

 

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