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#Post#: 247--------------------------------------------------
how to make sulfuric acid using CuSO4
DIR By: Michel
Date: May 27, 2012, 9:01 am
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www.youtube.com/watch?gl=US&hl=en&client=mv-google&v=C5DdPRcJoz8&fulldescription=1
has anybody experimented this?
I haven't and i don't trust everything i see on youtube. I'm
particularly concerned with the H+[sup]
at some point, i feel
2H[sup]+ +2e- --->H2 should be a preferred equation instead of
Cu2+ +2e- --->Cu
Maybe i'll find sometime to experiment this :)
#Post#: 251--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Henry
Date: May 27, 2012, 5:42 pm
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Ah, yes. I was about to comment on this.
I've tried to electrolyze Copper (II) Sulfate to yield Sulfuric
acid. It does indeed yield Sulfuric acid but at a very slow
rate. Took me about... 2 days to clear a fairly diluted solution
of CuSO4.
It also depends on what kind of electrodes you use. I used
carbon and copper.
#Post#: 252--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Michel
Date: May 27, 2012, 6:15 pm
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--- Quote from: Henry link ---
>
> Ah, yes. I was about to comment on this.
>
> . I used carbon and copper.
>
--- End Quote ---
i suppose you used a Copper cathode and a graphite anode
a copper electrode is not very ideal, but since the
concentration of H2SO4 is low, no problems
Then two days? That's long. What was the volume (ml) of your
electrolyte. Did you use concentrated or dilute CuSO4 ?
What was the voltage of your battery?
Pls give more info...i want to try this out, with the view of
maximizing yield
#Post#: 253--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Henry
Date: May 28, 2012, 3:03 am
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I used an approximate 150mL of 0.418M CuSO4 with a battery of 6
V.
I have no idea why it took my 2 days... Maybe it's because I
keep moving the solution. You'll need a good carbon electrode or
platinum electrode which doesn't corrode away.
I've wanted to try the whole experiment again with car battery,
but I couldn't get one around. Good luck :)
#Post#: 254--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Michel
Date: May 28, 2012, 3:24 am
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--- Quote from: Henry link ---
>
>
> I have no idea why it took my 2 days...
>
--- End Quote ---
it took 2 days probably because you used 6V. Higher voltage,
higher current, faster rate, and the battery was running down as
the electrolysis progressed. I usually use 12V for most
electrolyses. This electrolysis requires minimum 0.9V to work.
#Post#: 255--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Michel
Date: May 28, 2012, 3:32 am
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--- Quote from: Henry link ---
>
>
>
> I've wanted to try the whole experiment again with car
battery, but I couldn't get one around. Good luck :)
>
--- End Quote ---
car battery electrolyte is sulfuric acid, you wanted to use
sulfuric acid to prepare sulfuric acid?
Anyway, even if you'd diluted the car battery electrolyte,
electrolysis of the dilute solution won't significantly change
it's concentration
#Post#: 256--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Michel
Date: May 28, 2012, 4:35 am
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henry...i have another question.
Did you notice any gas evolution from the cathode later on in
the electrolysis?
#Post#: 257--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Henry
Date: May 28, 2012, 5:12 am
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No no. What I meant was I wanted to use a car battery as the
power source.
Yes. There is gas being produced.
#Post#: 258--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Michel
Date: May 28, 2012, 8:18 am
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--- Quote from: Henry link ---
>
> No no. What I meant was I wanted to use a car battery as the
power source.
>
>
>
--- End Quote ---
Ok, sorry for the misconception.
--- Quote from: Henry link ---
>
>
> Yes. There is gas being produced.
>
--- End Quote ---
This means that, at some point, when the H+ concentration is
sufficiently high, it is discharged, instead of Cu2+. At this
point H+ from The anode reaction is discharged at the cathode.
2H+ +2e- ---->H2.
I think you weren't seeing bubbles from the cathode at the start
of the electrolysis?
Since i don't have a pH meter now, maybe when I do mine,
hydrogen discharge from the cathode will tell me it's time to
stop:)
were you judging the progress of the reaction from the color of
the solution?
There's a maximum amount of H2SO4 that can be obtained during
this process, but it might be difficult to calculate because of
water evaporation.
#Post#: 260--------------------------------------------------
Re: how to make sulfuric acid using CuSO4
DIR By: Henry
Date: May 28, 2012, 7:56 pm
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The conversion is complete when no more Copper is being
precipitated out of the solution.
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