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Splitting water at home


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it has nothing to do with elecrolysis, no.

 

also, IF you decide to try these co2 bombs, make sure you take an airgun with you!

if the device fails to explode, then shoot it from a safe distance, DO NOT leave it there for a little child or an animal to find later on!

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Woelen, you`re not confunsing these with COBs are you?

although I agree at close range they can be quite dangerous, they`re also quite easily disarmed with an airgun or the likes, personaly after you`ve seen one you`ve seen them all and it`s just a waste of Dry Ice after that.

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Woelen' date=' you`re not confunsing these with COBs are you?

although I agree at close range they can be quite dangerous, they`re also quite easily disarmed with an airgun or the likes, personaly after you`ve seen one you`ve seen them all and it`s just a waste of Dry Ice after that.[/quote']

I don't know the word COB, but what I mean is those young boys (sometimes girls), who just are looking for a blast, have no real interest in chemistry (or more in general in science) and just are looking for an easy and lazy way to impress their friends. They do a lot of harm to amateur chemistry, because if accidents happen with chemicals, it is almost always with that type of persons. They are the people who make getting reagents and equipment more and more difficult, due to liability issues.

 

This is what annoyed me most at the original stupid post about the CO2 bomb.

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They do a lot of harm to amateur chemistry' date=' because if accidents happen with chemicals, it is almost always with that type of persons. They are the people who make getting reagents and equipment more and more difficult, due to liability issues.

[/quote']

 

Amen to that!

 

I`ll PM you about COBs rather than say on here.

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I split tap water, though I didn't test the gases. I used pieces of aluminium foil as electrodes, crocodile clips and a simple 9 volt battery used in transistors. I took long for the bubbles to start forming, but once they started, they were produced at a constant rate.

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I like it :D .But the guys in the video were throwing the thing before it exploded. Hence' date=' should I throw it or it just explodes by its own??

Btw, this does not have anything to do with electrolysis does it? So I won't have to produce any h2 or o2 am I right?[/quote']

 

Once you close the lid I suggest throwing it or rolling it (it does explode on its own...usually). Waiting to time it like they did is to risky (although you can hear it give a warning crack...). Overall it's too risky to hold onto it though. That air gun is a good idea though... if you do do it.

 

I don't know the word COB' date=' but what I mean is those young boys (sometimes girls), who just are looking for a blast, have no real interest in chemistry (or more in general in science) and just are looking for an easy and lazy way to impress their friends. They do a lot of harm to amateur chemistry, because if accidents happen with chemicals, it is almost always with that type of persons. They are the people who make getting reagents and equipment more and more difficult, due to liability issues.

 

This is what annoyed me most at the original stupid post about the CO2 bomb.[/quote'] Are you saying I'm one of these people? I don't really get why you think my post is stupid though.. I told him about the dangers and just wanted to give him something simple that would give him the loud 'bang' he wanted. Sometimes its simple things like this that spark people's interest in chemistry.

 

I do understand your complaint of people using these things stupidly (i.e. disregarding safety issues). Those people do make me upset.

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yes, and yes it can be if you`re not carefull.

although you don`t need to make it very concentrated to work well, you still need to be carefull of spilling it and also what electrodes you use (aluminium is no good for instance).

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Are you saying I'm one of these people? I don't really get why you think my post is stupid though.. I told him about the dangers and just wanted to give him something simple that would give him the loud 'bang' he wanted. Sometimes its simple things like this that spark people's interest in chemistry.

I did not say that you are one of these people. I was only annoyed about this CO2-bomb stuff. I still think that that kind of things is not very funny and does not add much to the hobby of chemistry. But of course, you may have your opinion ;) and I'm certainly not intending to insult or discomfort other members of this forum.

 

Indeed, I agree with you that this kind of things can spark people's interest in chemistry (and in fact, I also sometimes do boom/smoke/light things with my kids, just for fun), but to my opinion such things must not be discussed on an internet forum, but have to be conducted personally with the less experienced persons. While you and your audience have fun about the noises, smoke or whatever, you also can explain things, warn for risks, etc. That makes the things even more fun and that really sparks people's interest.

 

 

yes' date=' and yes it can be if you`re not carefull.

although you don`t need to make it very concentrated to work well, you still need to be carefull of spilling it and also what electrodes you use (aluminium is no good for instance).[/quote']

Try to do electrolysis of dilute NaOH-solution with simple copper wires. Remarkably, the anode does not dissolve, but oxygen is evolved at the anode, almost in a 1 : 2 ratio with the hydrogen, evolved at the cathode.

 

This fact is most remarkable, because I would expect the copper wire to dissolve at the anode. Is there someone here, who can explain this?

 

If you do the NaOH-electrolysis, please be careful. Even dilute NaOH-solutions are quite nasty for your skin and you must be especially careful, not to smear some of this in your eyes by accident. That is most easily done if you move your hands towards your eyes, without thinking!

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Try to do electrolysis of dilute NaOH-solution with simple copper wires. Remarkably' date=' the anode does not dissolve, but oxygen is evolved at the anode, almost in a 1 : 2 ratio with the hydrogen, evolved at the cathode.

 

[/quote']

 

Can I use graphite electrodes?? And since the solution is highly corrosive, what container should I use for the solution? Is plastic suitable, or is it too weak??

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I did not say that you are one of these people. I was only annoyed about this CO2-bomb stuff. I still think that that kind of things is not very funny and does not add much to the hobby of chemistry. But of course' date=' you may have your opinion ;) and I'm certainly not intending to insult or discomfort other members of this forum.

 

Indeed, I agree with you that this kind of things can spark people's interest in chemistry (and in fact, I also sometimes do boom/smoke/light things with my kids, just for fun), but to my opinion such things must not be discussed on an internet forum, but have to be conducted personally with the less experienced persons. While you and your audience have fun about the noises, smoke or whatever, you also can explain things, warn for risks, etc. That makes the things even more fun and that really sparks people's interest.

[/quote'] Thanks for clearing that up :). I didn't want to offend someone or make myself sound like a stupid 'kewlie'.

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Can I use graphite electrodes?? And since the solution is highly corrosive, what container should I use for the solution? Is plastic suitable, or is it too weak??

 

yes graphite is fine, plastic`s fine as a container too, just avoid Glass or Aluminium.

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I`m not sure about organic acids, if they break down or not?

it should certainly conduct better than fresh water, metal citrates though.... that part I`m uncertain about, they will be created, but I`m not sure about what, if any gas other that the H and O maybe liberated during it.

 

my gut instinct says there will be non, just the plain H and O.

I`de wait until someone else with experience in organic metal salts arrives :)

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I`m not sure about organic acids' date=' if they break down or not?

it should certainly conduct better than fresh water, metal citrates though.... that part I`m uncertain about, they will be created, but I`m not sure about what, if any gas other that the H and O maybe liberated during it.

 

my gut instinct says there will be non, just the plain H and O.

I`de wait until someone else with experience in organic metal salts arrives :)[/quote']

At the cathode you may expect mainly hydrogen gas. At the anode things are quite different. Citric acid is easily oxidized, the oxidation products being carbon dioxide and acetone. Of course, you still me get some oxygen, but that certainly will not be the only product. Just try it and probably, after a long time of electrolysis you will notice the smell of acetone.

 

If you oxidize aqueous citric acid with some oxidizer like warm KMnO4/H2SO4, then you'll also smell the acetone.

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The thing is that you cannot use salt to boost the conductivity of the water. For electrolysis, sulfuric acid is often used. The green thing is the insoluable salt of copper chloride, or whatever metal you have for the electrodes. You have to use a unreactive metal for the electrodes. Otherwise, if you run it long enough, like a whole day or so, one of the electrodes would actually dispear. and you will see some green stuff condensed at the bottom. Sodium ions will combine with some of the oxygen from the decomposition and remain disolved in the water.

 

An interesting thing is that you can do the same thing without electricity. Use a very strong magnet (like those super strong ones from the harddrive), It's going to do the exact samething. But you cannot see it as you do if you use electricty. If you leave it there for a night, the second day, you will see the water green. :)

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I repeated the experiment with a 30V rectifier I found, tap water and two screws as electrodes. Electricity is free here so I switched the power on and came back after a while. I got the usual hydrogen the tested positive; but no gas was given off at the Anode. Then some more time later, a green ppt. started forming. It kept getting bigger and the bottom of the glass vessel seemed like like a greeen filter. Then I switched the power off and left it for a few hours. The ppt. had turned brown !

 

Thus I conclude that the screw must've been made of Iron and the green ppt. was the Fe reacting with the O2 evolved immediately to form Iron (II) Oxide. On standing it was oxidised and formed Iron (III) Oxide, thus the brown colour of Fe(III) ions.

 

Am I right ? :confused:

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Am I right ? :confused:

Almost...

 

At the anode you do not even get any O2 at first. The iron is oxidized immediately, apparently to Fe(2+) ions, which forms the green precipitate with hydroxide formed at the cathode.

 

Indeed, after some time, the iron (II) species is oxidized to an iron (III) species by oxygen from the air. So, the green color goes to a brown color.

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At the anode you do not even get any O2 at first. The iron is oxidized immediately' date=' apparently to Fe(2+) ions, which forms the green precipitate

[/quote']

 

Thats what i meant.

 

 

with hydroxide formed at the cathode

 

 

What hydroxide do you mean?

 

I forgot to add, the hydrogen formed this oily looking layer of bubbles once it reached the surface. Any idea why this happened ? It also happened the previous time, when I used Al electrodes.

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