Rainwater
National Hazard
Posts: 800
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
Proper disposal of asorbic acid sulfate
I have been painting fiberglass substrate using a mix of graphite, polyurethane, thinner then electroplating my core material.
Getting very good results.
I want to try using copper nanoparticles by mixing asorbic acid and copper sulfate.
I have found many videos showing the process, but not many details about what the reactions are.
Im assuming that the ascorbic acid acts as a cation to the sulfate ion in a single displacement type reaction. Still digging into this process.
Organic chemistry is so weird. This thing has 3 oh groups and is an acid. Lots to learn
what is the proper method for disposing of the solution after the copper is extracted?
"You can't do that" - challenge accepted
|
|
|
B(a)P
International Hazard
Posts: 1116
Registered: 29-9-2019
Member Is Offline
Mood: Festive
|
|
I think this might be what you are looking for.
SM link
Woelen link
|
|
|
Rainwater
National Hazard
Posts: 800
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
Very good read. It seems the real reaction is still a mystery
"You can't do that" - challenge accepted
|
|
|
Texium
Administrator
Posts: 4516
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Quote: Originally posted by Rainwater  | | Im assuming that the ascorbic acid acts as a cation to the sulfate ion in a single displacement type reaction. Still digging into this process.
Organic chemistry is so weird. This thing has 3 oh groups and is an acid. Lots to learn |
While I can’t
tell you what is happening here either, I can tell you that it’s not this. Organic chemistry seems weird when all you know are the simplest
inorganic reactions (single displacement, double displacement, etc). Once you learn more about it, you’ll realize that it isn’t weird, it’s just
different, and you can’t think about it in the same context as simple ionic reactions.
For your proposal to be happening with ascorbic acid becoming cationic, that would mean one of the hydroxyl groups would have to become protonated to
H2O+. This would be a strongly acidic species that requires a strong acid to make. Something like sulfuric acid. Let’s say
sulfuric acid is actually formed in this reaction (which is possible). You now have a dilute mixture of sulfuric acid and ascorbic acid oxidation
products in solution. The sulfuric acid could reversibly protonate the ascorbic acid’s hydroxyl or ketone groups just as it protonates water to form
hydronium ions, but the key word here is reversible. Until a change occurs that causes something to fall out of solution or otherwise upset the
equilibrium, you’ve just got an aqueous soup of various ions with protons transferring back and forth. It’s similar to if you mixed sodium nitrate
and potassium chloride in aqueous solution. You’d no longer have sodium nitrate and potassium chloride, you just have a mixture of four different
ions. The ions don’t “remember” who they were originally associated with once they’re all bouncing around in solution. You wouldn’t be able
to isolate the umm “ascorbatonium sulfate.” It would lose water and form an alkene (and realistically, a nasty mess) if you concentrated it too
much.
Anyway, the point of this unexpectedly long-winded post is that an “ascorbic acid sulfate” doesn’t exist as an isolable compound, and based on
our current knowledge, you can probably treat the waste solution as a mixture of non hazardous organic products and dilute sulfuric acid. There may be
copper(I) ions present as well, so perhaps try adding some NaOH solution to the waste to see if there’s a yellow precipitate. The waste should be
non hazardous enough to dump down the drain though.
|
|
|
Rainwater
National Hazard
Posts: 800
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
Thanks. I'll try adding some lye. Love color changes.
"You can't do that" - challenge accepted
|
|
|
clearly_not_atara
International Hazard
Posts: 2696
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
The reaction of ascorbic acid with copper sulfate is a redox reaction; Cu2+ is reduced to Cu+ or Cu (don't remember) and ascorbic acid is oxidized to
dehydroascorbic acid. Sulfate ion is highly inert and is unchanged.
Ascorbic acid is a reductione:
http://en.wikipedia.org/wiki/Reductone
which is a ketone attached to a 1,2-dihydroxyalkene. Oxidation yields a tricarbonyl. Normally this would be reversible: the keto-enediol is a reducing
agent, the tricarbonyl is an oxidizing agent. But ascorbate is a particularly good reducing agent among the reductic acids because the product
hydrolyses to give 4,5,6-trihydroxy-2,3-dioxohexanoic acid (diketogulonate), which is irreversible (some studies indicate HI may convert DKG back to
ascorbate, but otherwise irreversible).
[Edited on 04-20-1969 by clearly_not_atara]
|
|
|
Rainwater
National Hazard
Posts: 800
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
Yall got me searching for a textbook now. Openstax doesn't have much in their chemistry book about this subject. Just 1 chapter.
Found one by Robert C. Neuman, Jr. Gonna give it a good read. Its pdf. I perfer hardcovers
"You can't do that" - challenge accepted
|
|
|
Rainwater
National Hazard
Posts: 800
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
So i took the waste solution and then slowly added 25% by weight NaOH(aq) until the solution could not be seen through. Let it settle into layers,
then dripped in more NaOH to check if more percipitate formed as the drops enter the solution they crash down through the upper layer. As soon as they
contact the yellow, an almost black blue formed then varnishes. For a short time, 3 layers are formed, light green (top) blue/red (middle) light
orange bottom.
https://youtu.be/KOHqL406-7k
After a few minutes of research. It looks like i should be forming copper(ii) hydroxide.
But thats not the case because when i NaOH +CuSO4 and compared the results. They are very different.
https://youtu.be/ZVspYQZP-Mk
The closest match in color i can find is Copper(i) hydroxide
"You can't do that" - challenge accepted
|
|
|
Rainwater
National Hazard
Posts: 800
Registered: 22-12-2021
Member Is Offline
Mood: indisposition to activity
|
|
I believe Copper(i) hydroxide is confirmed because the solids in solution are turning a beautiful red.
This picture does not do these colors justice.
"You can't do that" - challenge accepted
|
|
|
Amos
International Hazard
Posts: 1406
Registered: 25-3-2014
Location: Yes
Member Is Offline
Mood: No
|
|
It is widely referred to as "hydrous copper(I) oxide" which in practice is not very different from a metal hydroxide. The only real way to keep the
yellow color stable long-term is to keep it cool and underwater in a sealed vessel where oxygen can't contact it.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
