[science2000]

Hello everyone,

In theory, can you make sulfuric acid from electrolysis of a Copper(II) Sulfate solution? What would be a suitable, and affordable, anode and cathode for such a reaction?

I've tried to do this with a nickel coin as the anode and pencil graphite as the cathode and formed a very acid solution but rich in nickel. I've also tried it with a silver coin as the anode, but the silver was also made chemically active by the bubbling O2 and was displacing the very copper forming at the anode!

[Borek]

You need anode that will not dissolve and cathode identical with what you are trying to remove from the solution.

[billnotgatez]

Would using carbon electrodes for both the cathode and anode work? Do you really need to have specific electrodes or just un-reactive electrodes? Then you could get electrodes from certain types of discarded batteries.

[Borek]

Carbon cathode may work, but it will soon get covered with copper so you will have copper cathode after few minutes. No idea about possible side reactions, I would start with copper just to avoid additional problems.

[constant thinker]

Carbon is probably the best bet. You can get it cheaply from those lithium lantern batteries.

Here is a link to one way to extract the carbon rods.
http://theodoregray.com/PeriodicTable/Stories/006.2/index.html

If your lazy, you can buy them from United Nuclear, but it's more expensive.

[billnotgatez]

There are very cheap flashlight batteries that have carbon rods in them. They typically have the words heavy duty printed on them. They are easy to break into but the electrolyte is messy. Wash your hands and the rod after the extraction. Use ones that have spent charge for efficiency sake.

[science2000]

Okay guys, I took some of a carbon rod from a C-sized battery, but the bubbling of the electrolysis is chipping off many little pieces of carbon into the solution. Is this normal? Or did I use a crappy battery? It was a "GP" brand.

[billnotgatez]

http://sci-toys.com/scitoys/scitoys/echem/echem.html

We are getting the same results you are
I do not understand why the above link was doing better
Possibly quality of electrodes
We noticed that ours may not to be truly solid all the way though

We are trying AA and will let you know

edit
We had a little delay

[billnotgatez]

It even happens with the smaller electrode. In all cases it stops after a bit, but I think I would need to do a long-term test to make sure the carbon electrode did not entirely decompose. By the way we put a small amount of sodium carbonate (swimming pool stuff) to catalyze the process.

[science2000]

Okay, I guess the good carbon electrodes might have to be bought. But I noticed that the carbon particles settle to the bottom of the solution by the next day, so hopefully it would just be inconvenient.

[billnotgatez]

so hopefully it would just be inconvenient

My hope as well