Ac electrolysis

[Jay-qu]

Three phase is just 3 waveforms of standard AC but each out of phase with each other, this doesnt make a difference.

[hallenrm]

Definitely not a practice to be recommended... :D ...:hyper:

 

Only as much as it is recommended to smoke cigarettes, drink liquor or use drugs!!!

 

Most likely because shaving blades aren't made of copper. See if you can find old coins - where they've oxydised, they've got green gunk on it. It's copper "rust", if you will.

Being AC, that's most likely bubbles of steam forming on the blade surface, very much like a kettle element would create tiny bubbles of gas which will grow bigger and bigger as the water warms up till the whole lot eventually boils.

 

No, the phenomenon of electrolysis depend only on the presence of a minimum potential across the electrodes. The electrode material only affects the electrode overpotential. So, whether it is AC or DC electrolysis can take place, the only difference could be that the cathode and anode change places between themselves, when it is AC, at the frquency of the AC; so it won't be a particular gas that is evolved at a particular electrode.

 

Nah - most likely copper. And the reason making a dead short through shaving blades don't melt your wall plug is because it's actually heating up because of higher resistance - the current is actually doing some work. Same with a kettle element, which is also a dead short. It has high resistance, so the current flow will have to do some work in passing through it, resulting in warming the element up. When dead-shorting naked copper wire, especially in a saline solution, there's not a lot of effort for the electrons to pass, and it should actually trip your DB box before the plug could melt.

 

That's true regardless of the electrode material, the current drawn from the mains depends on the resistance between the electrodes; addition of salt reduces the resistance and increasing the distance between the electrodes increases it.

 

Don't try any of this at home, kids...:doh:

 

In India, kids often do it, just to save the expense on an heating element. Yes it requires some precautions!!!:)

[Vending]

No

 

I think you are wrong here. Care to explain your answer?

 

It seems to me that all that is needed is the correct potential for the splitting of water. Electron transfer from the electrode is most likely on the micro to nanosecond timescale and so most ossilating currents should not be a problem.

 

But perhaps you have a different reason for you answer?

[Jay-qu]

Although that was a rather rude blunt and non-scientific answer, the answer has been explained in subsequent posts. The electons in AC ocsillate, they move backwards and forwards, common household AC is 60Hz here and I think 50Hz in the US. Therefore there is no lasting effect upon using this kind of current. Yes perhaps on a molecular level the water may be oxidised or reduced, but the reaction would quickly be reversed in .02seconds when the current flips.

[GAHD]

I beleive this applies:

 

http://hypography.com/forums/chemistry/6608-hho.html

 

some of the claims in the patents and whatnot indicate the current-flow *is* ac at the generator, if my memory servs.

[hallenrm]

Therefore there is no lasting effect upon using this kind of current. Yes perhaps on a molecular level the water may be oxidised or reduced, but the reaction would quickly be reversed in .02seconds when the current flips.

 

Care to substantiate your claim scientifically?

[Jay-qu]

how so? that is the extent of what I can claim to know scientifically.. alternating current results in no permanent transfer in electrons. If I am mistaken correct me, but dont say im not been scientific about it.

[hallenrm]

What I am alluding to is the claim that within 0.5 sec. no electrochemical proccess can occur. I think it is just your impression and not based on any hard scientific fact. Let me confess, that is what it appeared to me also, but when I reasoned it for awhile, i see no reason to believe that within half a second no electrochemical reaction can take place!!!

[Boerseun]

What I am alluding to is the claim that within 0.5 sec. no electrochemical proccess can occur. I think it is just your impression and not based on any hard scientific fact. Let me confess, that is what it appeared to me also, but when I reasoned it for awhile, i see no reason to believe that within half a second no electrochemical reaction can take place!!!

Not intentionally picking nits, but you're referring to a 2Hz AC system. Standard household AC is betwen 50 to 60Hz, depending on the grid. This means your half-a-second comes down to 0.02 second per cycle.

If your frequency is as low as 2Hz, the alternating current won't be able to do any useful work through induction, and will be virtually useless.

[Jay-qu]

apart from the fact of the frequency, the point i was making is that even if a reaction takes place, it will be reversed when the current reverses.

[hallenrm]

apart from the fact of the frequency, the point i was making is that even if a reaction takes place, it will be reversed when the current reverses.

How, please explain, suppose some oxygen is produced at one electrode by the electrolysis of water, do you mean to say that this electrochemical process will be reversed tp produce water at that electrode.

 

I can now sense the real culprit, usually one tends to equate an electrochemical process with electrplating or electro-dissolution, say the electrochemical process that takes place on a copper electrode with copper sulfate as the electrolyte. But electrolysisis different.

 

As regards the response of Boerseun

but you're referring to a 2Hz AC system. Standard household AC is betwen 50 to 60Hz, depending on the grid. This means your half-a-second comes down to 0.02 second per cycle.

If your frequency is as low as 2Hz, the alternating current won't be able to do any useful work through induction, and will be virtually useless.

 

Yes, it was an inadverent mistake, Thanks for pointing out. But the process in question is electrolysis and not inductive load. An AC of that low frequency would be much more effective by the mechanism I have outlined.

 

Here's a link which readers of this thread would find useful and interesting/

 

By the way, the real crux of the problem is electrochemical kinetics, that is how fast does the electrolytic reaction occurs on the electrode. I have been searching but without success, anyone who has any clues please help! :)

[Turtle]

I propose a simple experiment to resolve the issue of whether 50 -60 Hz AC current electrolyzes water, that is to say breaks water molecules into Oxygen & Hydrogen.

 

First, use a low voltage AC such as from a model train transformer - most of these have 17 VAC terminals to run lights & switches on the train board.

With the normal setup of a tank of salted water & 2 electrodes, submerge 2 test tubes or similar vessels in the electrolyte & then carefully invert each one over an electrode. Turn on the juice. If the electrolyte level in the tubes drops, then electrolysis is occurring; otherwise, not. ;) :)

 

Postscript: The above experiment yields ideal results only if the electrodes consist of pure gold, as it does not electrolyze.

[hallenrm]

This experiment can also work with carbon rods salvaged from a used drycell.

[Jay-qu]

How, please explain, suppose some oxygen is produced at one electrode by the electrolysis of water, do you mean to say that this electrochemical process will be reversed tp produce water at that electrode.

 

yes that is what i suppose, and it was pure thought that brought me to the conclusion, I beleive the experiment would prove this.

[Turtle]

yes that is what i suppose, and it was pure thought that brought me to the conclusion, I beleive the experiment would prove this.

 

I expect that each electrode produces both Oxygen & Hydrogen, that it doesn't recombine, & that the gases fill the tubes displacing all the electrolyte in them after some period of time.

 

I have the necessary apparatus & plan to conduct the experiment in the next few days.

 

This experiment can also work with carbon rods salvaged from a used drycell.

Any conductor is sufficient. Do you mean that carbon doesn't electrolyze?

 

:hyper:

[hallenrm]

Any conductor is sufficient. Do you mean that carbon doesn't electrolyze?

 

:cup:

 

Well we have used carbon rods extracted from torch-light carbon zinc drycells for many electrochemical experiment (as a replacement of platinum electrodes).!!

[Jay-qu]

It just makes sure that the electrode doesnt take place in the reaction. Now I remember a mythbuster episode, where they tried to break out of a jail cell, they where both trying to use electrolysis to oxidise the metal bars and break out. One of them was using AC while the other DC, after a few days of trying the DC had actually reduced the diameter of the bar while the AC didnt do a thing except boil the salsa they where using as an oxidant..