Ac electrolysis

[hallenrm]

Good work Turtle:) congratulations for your success and thanks too for proving my thoughts. I could not participate in the discussion in the past few days, as I was away to a place that dids not provide convenient Internet access.

 

I am contemplating on your obsevations say the deposits on the electrodes and shall get back soon with my thoughts.

[hallenrm]

I have prepared copper electrodes & zinc-plated steel.

 

That I suppose explains some of your observations, Turtle. The electrochemical cell that you have assembled is capable of more than one electrochemical reactions. Besides electrolysis of water it is also carrying out electro-dissolution, electroplating, and electro-oxidation of zinc and copper that are participants in the whole electrochemical arena that you have enacted. It is also the reason why you have collected so little gases, a large part of the electric current is consumed by the other processes. I think the results with carbon electrodes on both ends would be different (one can use carbon rods commonly employed for spark welding. Platinum or gold electrodes would be of course very expensive and out of the reach of an amateur experimentalist. :)

[Turtle]

... Turtle. The electrochemical cell that you have assembled is capable of more than one electrochemical reactions. Besides electrolysis of water it is also carrying out electro-dissolution, electroplating, and electro-oxidation of zinc and copper

___Because I sealed the copper wires where they connected to the zinc electrodes with acrylic polymer, I exposed no copper to the reaction.

___I have taken the setup down and the zinc electrodes emerged from a rinse with a black patina. As you have suggested Charlie, many variations of the experiment remain for those interested in carrying them out.:shrug: :hihi: :sun:

[Yakov]

Earlier today I created my own electrolysis machine using AC current.. without knowing that I was supposed to use DC. I used 4 pencil leads(carbon) per electrode. I just cut the end off a typical cord, stripped the casing off, and wrapped the copper wire around my bundle of carbon rods. I soldered the connection so it would stay in place. I then concealed this in a plastic pitcher and connected it to a trash bag (to trap the gas). When I plugged it in gases came off both electrodes rapidly and heated the water fast. the bag filled fairly fast but I have a feeling a lot of it was steam (a thick visible mist accumulated in the pitcher). My plastic container was too weak and began to heat too much so I unplugged it. I only had it going for 30 seconds maybe. there was a good amount of NaCl in the water i used. But the pencil lead carbon rods seemed to work great. also Turtle Ive lit balloons with maybe a liter of hydrogen/oxygen in them and the explosion is loud but nothing i wouldnt recomend with your experiment. Is there a way to convert ac to dc? Did i make a mistake somewhere to make my experiment so exothermic? Im going to try with a larger container tommorow using the same electrodes.

[Turtle]

...1)Turtle Ive lit balloons with maybe a liter of hydrogen/oxygen in them and the explosion is loud but nothing i wouldnt recomend with your experiment.

2)Is there a way to convert ac to dc?

3)Did i make a mistake somewhere to make my experiment so exothermic?

4)Im going to try with a larger container tommorow using the same electrodes.

 

1) Who me?:eek: :eek: I have sworn an oath not discuss my activity or lack therof with balloons and/or plastic bags and/or other containers containing flammable mixtures whether produced by electrolysis or otherwise and/or in the presence or absense of military and/or government personnel and/or their families.

2)Yes; a rectifier. :) link

3) Not if you wanted heat.;)

4):D See #1.:cup:

[hallenrm]

there was a good amount of NaCl in the water i used. But the pencil lead carbon rods seemed to work great.

 

If you want less steam and heat try with less saline water. Remember more the conductivity of electrolyte, more current will flow through it and heat it up:)

[Yakov]

Thank you I will try it and get back to you on how it works.. is it possible with high enough voltage to do the electrolysis with distilled water?

[Jay-qu]

Water does not conduct electricity very well.. not much current gets through. A given chemical reaction requires a certain amount of energy, possibly by pumping it up you could push more current through. However I dont recomend it. All experiments I have done just use some electrolyte to make the water conduct better.

[Vending]

If you want less steam and heat try with less saline water. Remember more the conductivity of electrolyte, more current will flow through it and heat it up:)

 

I do not agree with your reasoning here. The higher the conductivity, the lower the resistance, the less energy is lost to heat. That is to say that heat is generated by pushing current through a resistor. This is how an electric heating element (as in an electric stovetop) works. You run current through the element which is a resistor and you generate heat.

 

I think that quite the opposite of what you suggest would happen, that is, as you increase the salinity of the solution, you will lower the resistance and, hence, reduce the energy lost to heat.

 

Yakov:

For many electrochemical set-ups people us 0.1 molar supporting electrolyte -- i would use at least this much. Also, i do not know exactly what your set-up was, but i would recommend that you move the two electrodes as close together as is possible (but still far enough away to collect the gasses seperately, if that is what you wish. If you are collecting them together, then there is obviously no problems). As you increase the distance between the electrodes you will increase the effective resistance of the circut and you will lose more energy to heat.

 

Just my two cents.

[Yakov]

thank you vending. Since we are useing AC current collecting the gases seperatly isnt a possibility. so putting them closer makes a lot of sense. originally i put them as far apart as possible. dont know where i got that logic but ill adjust my experiment. homefully that will reduce heat.

[hallenrm]

I do not agree with your reasoning here. The higher the conductivity, the lower the resistance, the less energy is lost to heat. That is to say that heat is generated by pushing current through a resistor. This is how an electric heating element (as in an electric stovetop) works. You run current through the element which is a resistor and you generate heat.

 

I think that quite the opposite of what you suggest would happen, that is, as you increase the salinity of the solution, you will lower the resistance and, hence, reduce the energy lost to heat.

 

There is a difference in between electrolyltic conduction and mettalic conduction. While the electrolytic conduction is through the movement of ions to the electrodes, Metallic conduction, as in the case of metal resistors, is through promotion of electrons to the conduction band, which then move through the wire/heating element.

 

My observations, as regard to heating tap water with the help of two stainless steel shaving blades as electrodes, suggests that addition of an electrolyte is really not neccessary, higher the electrolyte concentration more is the electrode reactions on the two electrodes which (I beleive, biut not very sure) proceeds at lower voltages than electrolytic decomposition of water. :hihi:

[GAHD]

...Is there a way to convert ac to dc?

A power Rectifier? It's a pritty cheap circuit to make, and its components are available off the shelf or scavenged out of other electronics.

 

wiki is da bomb

 

You could even just take the power supply for a game system and use that for a low voltage DC.

[Yakov]

Thanks.. Will an old laptop power cord work?.. ill give that a shot.

[Jay-qu]

lol, maybe.. you can get basic rectifying circuits at electronics stores, either to put together yourself or pre-made. And that would definitly work.

[GAHD]

Thanks.. Will an old laptop power cord work?.. ill give that a shot.

If the output from the laptop cord says "x" volts DC, then yes. It should be labeled.

[Yakov]

I spent about 80 dollars on random little electric stuff at radio shakc the other day and havent used any of it.. ive found that there is a surprisingly small amount of information on the internet for begining electricians. Ill look up the rectifier though. I havent had time between school and work to work on my electrolizer (is that the word).. or would you call it an electrolysis machine.. anyway. thank you all.

[Jay-qu]

electrolytic cell..

 

rectifiers consist of a transformer, half or full wave rectifier (diodes) a capacitor to smooth and a voltage regulator or load.