Greetings fellow nerds.
In a previous video I made sulfuric acid using a complicated sulfur dioxide and oxidizing liquid setup.
While pretty quick it was a little difficult to build.
Then in another video I showed how to convert sulfuric acid into copper sulfate.
But copper sulfate can easily be purchased in large quantities.
So the question is can copper sulfate be converted back into copper metal and sulfuric acid?
It can, and in this video we'll show how to do that based on electrochemistry.
First we'll need the carbon electrodes we obtained previously from batteries.
Attach and tape-on a wire to the top of the electrode
so you can connect it to a power source.
Now make a solution of copper sulfate,
the stronger the better,
and place in the bottom a copper electrode.
Attach the copper electrode to the negative terminal of your battery or power supply.
Attach the carbon electrode to the positive terminal
and suspend it above the copper electrode.
The electric current causes the copper ions to deposit out
as copper metal at the copper electrode.
The water is split at the carbon electrode liberating oxygen that bubbles out.
The leftover hydrogen ions combine with the left over sulfate to form sulfuric acid.
I'm using a six volt battery but a better method is if you can use a power supply
to adjust the current and find a current level that minimizes erosion
of the carbon electrode.
As you can see here the carbon electrode is eroding terribly
and filling the solution with particles.
The length of time for conversion depends on the current applied,
the coulombic efficiency, and the moles of copper sulfate in the solution.
Anyway, after about an hour,
I stopped mine and the next step is to filter out the suspended particles.
As you can see here I stopped it short so it's not fully converted.
It will have to be put back through the cycle until it's clear.
While that's going I'm going make another batch
but this time using a much better platinum electrode.
OK it's actually a platinum coated titanium electrode
but it's still the platinum that's doing all the work.
Once again we insert the electrodes into a copper sulfate solution
with the platinum electrode on top with a positive power connection.
And the copper electrode at the bottom with a negative power connection.
Turning on the current now.
Since the platinum dissolves extremely slowly
we can actually see the chemistry in progress.
The blue copper ions are being plated out the solution
and onto the copper electrode as a mass of spongy copper.
The solution is getting lighter as it's convert to sulfuric acid.
Now before you ask, these two electrodes are the best electrodes for this process
and other electrodes work terribly.
In fact many of them won't produce any acid at all.
You can try them but it'll probably fail horribly.
Now I'm told a lead dioxide anodes also work
but I haven't yet made one at the time I made this video.
Anyway, the conversion is now done.
As you can see,
we now have a solution of clear dilute sulfuric acid with bits of copper.
Just filter off the copper and similar to our previous video
boil down the dilute acid to concentrate it.
It can be tested by mixing with sugar and seeing if it turns to carbon.
So there we made sulfuric acid by using a copper sulfate solution and electrochemistry.
Although it's alot slower, it's alot easier to do than the metabisulfite method.
We'll continue to explore other ways of making sulfuric acid in upcoming videos.
So please subscribe, rate and comment.