Hi all,

Back before I knew much about circuits I used to build large negative ionizers. When I turned off the lights I'd see a blue glowing stream coming from the output, and shortly after have to flee the lab because of what that concentration of negative ions did to air quality in a confined space. Today I was wondering what would happen if I used a sharpened stainless rod (or something even more non-reactive) as the output of a negative ionizer into pure water. Rather than building all that up and finding out, which would take a few days at my slow pace, I thought I'd just ask the wiser heads on here. Curious to know if that glows blue/purple like it does in air and what happens to the water chemically. I first assumed dissociation into hydrogen and oxygen, but that's an electrolysis reaction and if that was the outcome I would think I'd have heard about this method of hydrogen production from the water welding/hydrogen fuel crowd.

Second question on a related topic, I've always liked electrochemistry and I'd like to learn more about it, does anyone have any good books they could suggest?

Thank you very much for your time and any thoughts you care to share.

 

The blue glow is caused by the emission lines of nitrogen and hydrogen in the air. The smell you experience is that of ozone when the air is ionized.

Pure water has no free ions. Hence you should not see any ionization.

 

I first assumed dissociation into hydrogen and oxygen

Yes, at current 1 A it will every second generate 0.058 cubic centimeter of oxygen + 0,116 cubic centimeter of hydrogen.

I've always liked electrochemistry and I'd like to learn more about it, does anyone have any good books they could suggest?

https://library.uoh.edu.iq/admin/ebooks/68990-bagotsky---fundamentals-of-electrochemistry-2e.pdf

 

The blue glow is caused by the emission lines of nitrogen and hydrogen in the air. The smell you experience is that of ozone when the air is ionized.

Pure water has no free ions. Hence you should not see any ionization.

Thank you very much for the information, I really appreciate it. I did want to ask, wouldn't the emission line of oxygen be present as well?

There actually wasn't a smell with this contraption. For a while I used bel jars and made ozone directly, that had a very distinct odor to it and ran me out of the lab a lot faster. This didn't, it was just that after a while I'd start to cough uncontrollably and have to leave the lab. I'm asthmatic so I'm likely more sensitive to things than other people. Still not sure what the precise etiology was because the general thinking was that negative ions don't do that but most people don't produce them in that quantity. Nearest equivalent would be to plug in about 100 negative ionizers in a 500 square foot area for a half hour (about the time it took to run me out of the lab, ozone was about 2 minutes.) To the best of my knowledge that experiment has never been run at all, let alone on people with asthma. The lack of a smell is the main reason I don't think it was ozone produced as a side effect. Though if ozone can be negatively ionized and that changes the smell it could have been gradual build up of ozone.

 

Yes, at current 1 A it will every second generate 0.058 cubic centimeter of oxygen + 0,116 cubic centimeter of hydrogen.

https://library.uoh.edu.iq/admin/ebooks/68990-bagotsky---fundamentals-of-electrochemistry-2e.pdf

Thank you for the math and reading suggestion, that's very helpful information.

I think I'm going to run this experiment (when time and energy permit) and see if any current flows. On the one hand pure water should be a perfect insulator and there is no conventional current path because only one electrode will be present, rather than the two that would normally be used in electrolysis. On the other hand a single high voltage might well break apart the bonds holding water together, which would then produce ions, rendering the pure water no longer pure and therefore conductive.

That book will take me some time to get through but I really appreciate having a starting point for this topic, thank you again.

 

On the one hand pure water should be a perfect insulator

Water is conductive because of dissociation:
https://chem.libretexts.org/Bookshe... dissociation of water is,conjugate acid H3O+.

only one electrode will be present, rather than the two that would normally be used in electrolysis

If you have discharge between one electrode and water,
then water is second electrode. High voltage and/or high frequency
easily finds path to water.

 

Water is conductive because of dissociation:
https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introduction_to_General_Chemistry_(Malik)/06:_Acids_and_bases/6.05:_Dissociation_of_water#:~:text=The dissociation of water is,conjugate acid H3O+.

If you have discharge between one electrode and water,
then water is second electrode. High voltage and/or high frequency
easily finds path to water.

Thank you. I thought that might be true but didn't want to contradict anyone by bringing it up.

Do you know if I would get an underwater glow corresponding to the emission lines of hydrogen and oxygen plus any nitrogen from the atmosphere that dissolved in the water during the reaction (assuming an open reaction vessel?) Or would the water displace the gas too quickly for emission lines to occur underwater?

Thanks again.

 

Do you know if I would get an underwater glow corresponding to the emission lines of hydrogen and oxygen plus any nitrogen from the atmosphere that dissolved in the water during the reaction (assuming an open reaction vessel?) Or would the water displace the gas too quickly for emission lines to occur underwater?

You can not create glow (corona discharge) in water.
But you can use spark or arc underwater discharge.

BTW, attached PDF may be interesting for you.