Sciencemadness Discussion Board - Possible to make Tartaric acid from Cream of Tartar?

Possible to make Tartaric acid from Cream of Tartar?

CHRIS25 - 27-10-2012 at 07:41

Tartaric acid has a formula of C4H6O6; Sodium Bitartrate (cream of Tartar) has KC4H5O6. Now the stupid thought I had - If I can take away the Potassium and kick out a single hydrogen atom then I have Tartaric acid? Laugh later but that was my immediate logic. Otherwise is there any 'Home' method I could use to get tartaric acid?

Looking at the chemistry supplier I have a choice of two products the L+tartaric which is hugely expensive 1Kg for 82 Euros; but then there is the other one which is called by another name of Dihydroxybutane Dioic Acid at 23 euros for 500 grams. I read that the former is the acid in its natural state, but I am not sure what they mean by this, natural state?

arsphenamine - 27-10-2012 at 08:15

It's slightly more complicated than expected.
The prep is a two pot reaction that relies on the lower solubilities of calcium salts.
Generate the calcium tartrate from cream of tartar and later acidify with sulfuric acid.

http://www.youtube.com/watch?v=Bt36jpk02Pk

CHRIS25 - 27-10-2012 at 11:04

Hi thanks for the video, watched, will try. Just hope my calcium carbonate is pure.

unionised - 28-10-2012 at 01:51

There's another route. Add a slight excess HCl which produces tartaric acid + salt then dry the solution down and dissolve the tartaric acid into alcohol (which doesn't dissolve salt, but will dissolve the acid.)

Hexavalent - 28-10-2012 at 01:56

Any specific alcohol, unionised? I assume you mean EtOH.

unionised - 28-10-2012 at 02:34

I meant ethanol, but I think IPA would also work.

CHRIS25 - 28-10-2012 at 02:38

Quote: Originally posted by unionised

There's another route. Add a slight excess HCl which produces tartaric acid + salt then dry the solution down and dissolve the tartaric acid into alcohol (which doesn't dissolve salt, but will dissolve the acid.)

Can you elaborate please. When you said add excess HCL, at what point what you referring to? Add HCL directly to the Cream of Tartar? And actually I don't think I can get hold of ethanol, the best I have is surgical spirit which is 90% ethanol and 5% methanol and the other 5% I have no idea. And what is IPA? Indian pale ale?

Just browsing through my catalogue and was very surprised to read that while they sell Pure 100% ethanol very expensive, very expensive, However they also sell what is called: Industrial methylated spirit at 99%, or 0.8g per mL weight. Now I have methylated spirit but it is no way this pure. So would the above work, or would it have to be the full grade purified ethanol?
[Edited on 28-10-2012 by CHRIS25]

[Edited on 28-10-2012 by CHRIS25]

Hexavalent - 28-10-2012 at 05:03

The surgical spirit should work just fine.

IPA is isopropyl alcohol.

CHRIS25 - 28-10-2012 at 06:20

Quote: Originally posted by Hexavalent

The surgical spirit should work just fine.

IPA is isopropyl alcohol.

Is this correct then: HCL+C4H5NaO6=C4H6O6+NaCL as simple as this? and if so, is the more labour intensive method as first proposed a bit redundant? and how do I then get the acid out of the alchohol?

[Edited on 28-10-2012 by CHRIS25]

[Edited on 28-10-2012 by CHRIS25]

Random - 28-10-2012 at 06:25

Quote: Originally posted by CHRIS25

Quote: Originally posted by Hexavalent

The surgical spirit should work just fine.

IPA is isopropyl alcohol.

yeah add hcl, evaporate until dry, add alcohol, filter, evaporate

unionised - 28-10-2012 at 06:57

The last time I checked, surgical spirit had things like castor oil, methyl salicylate, and diethyl phthalate in it and those won't evaporate off the tartaric acid easily.
It might work.
The way to check would be to let some of the spirit evaporate from a clean dish and see if there's any residue. If there is then you would do better to use something else.

The reason they don't do this commercially is that HCl is generally more expensive than H2SO4 and also alcohol is rather expensive.

CHRIS25 - 28-10-2012 at 14:34

Quote: Originally posted by unionised

The last time I checked, surgical spirit had things like castor oil, methyl salicylate, and diethyl phthalate in it and those won't evaporate off the tartaric acid easily.
It might work.
The way to check would be to let some of the spirit evaporate from a clean dish and see if there's any residue. If there is then you would do better to use something else.

The reason they don't do this commercially is that HCl is generally more expensive than H2SO4 and also alcohol is rather expensive.

I thought I answered this one, anyway I am doing what you suggest. Will see.

DJF90 - 29-10-2012 at 06:09

All these suggestions seem horribly convoluted. Dissolve the potassium bitartrate in e.g. 2M HCl, and extract the acidic solution with an organic solvent (I intend to use DCM). Evaporate the DCM to get the tartaric acid. I suspect the commercial salt is of the "natural" (although the other enantiomer also occurs naturally just more rarely) L-(+)-tartaric acid. Identification of enantiopure vs racemic acid can be done via melting point, but determination of which enantiomer is present is done by polarimetry or microscopy of well-formed crystals. The racemic acid can be produced by extended reflux in sodium hydroxide solution (I think the procedure is given in a textbook by Cohen, 1910, possibly in the forum library).

unionised - 29-10-2012 at 12:46

Quote: Originally posted by DJF90

All these suggestions seem horribly convoluted. Dissolve the potassium bitartrate in e.g. 2M HCl, and extract the acidic solution with an organic solvent (I intend to use DCM). Evaporate the DCM to get the tartaric acid. I suspect the commercial salt is of the "natural" (although the other enantiomer also occurs naturally just more rarely) L-(+)-tartaric acid. Identification of enantiopure vs racemic acid can be done via melting point, but determination of which enantiomer is present is done by polarimetry or microscopy of well-formed crystals. The racemic acid can be produced by extended reflux in sodium hydroxide solution (I think the procedure is given in a textbook by Cohen, 1910, possibly in the forum library).

LOL

Tartaric acid isn't soluble in chloroform, so I rather doubt it's soluble in DCM.
http://www.sciencelab.com/msds.php?msdsId=9925165

Your procedure simply won't work.

CHRIS25 - 29-10-2012 at 12:58

Also mr.Oxford, you might as well have been speaking chinese in code! But thanks for the excerpt from ye olde book.

And Unionised, nothing out of the ordinary with the surgical spirit, it seems to have evaporated without leaving a trace of anything...I presume then that I simply place my solution of tartaric acid and sodium chloride mixtute into the methanol and let filter, whereby the sodium chloride would be left behind in the filter bag? Or is this all too simple.....

Vargouille - 29-10-2012 at 13:25

It's probably that simple. What I would do, mind you, is give the tartaric acid a recrystallization or two afterwards to get rid of any other contaminants.

CHRIS25 - 29-10-2012 at 14:04

Quote: Originally posted by Vargouille

It's probably that simple. What I would do, mind you, is give the tartaric acid a recrystallization or two afterwards to get rid of any other contaminants.

Hi, whoops, you've got me there. How on earth do I re-crystallize? Do you mean dissolve it in water again and then de-hydrate?
Except of course it won't filter - it's too viscous. So scrub round the above. Just forgot to look at it, it can not be filtered. And I made silly mistake, it's potassium bitartrate not sodium, as I erroneously kept referring to it, so KC4H5O6...

[Edited on 29-10-2012 by CHRIS25]

[Edited on 29-10-2012 by CHRIS25]

Vargouille - 29-10-2012 at 14:39

Typically it's done by dissolving it in a minimum of hot water to dissolve most of it, filtering, or in your case, decanting, and allowing to cool slowly.

CHRIS25 - 29-10-2012 at 14:50

Ok. Well I just read that Potassium chloride is only partially soluble in Ethanol. So I should still get a reasonable tartaric produce. Otherwise I will have to opt for the long winded process from the YouTube demonstration. I have a little tartaric acid from a chemistry set, so I have the real thing for comparison.

DJF90 - 29-10-2012 at 18:33

@unionised: I was working off the top of my head without reference to any data. However thats not to say what I suggested won't work, it just needs a little tweaking. Performing the extraction with DCM might not work very well due to solubility reasons, but what about other organic solvents; ethyl acetate springs to mind, as does the use of chlorofom-ipa (7:3 might be appropriate in this case) - a well known solvent mixture for extraction of highly water soluble organics. Sorry to piss on your fire, asshole.

[Edited on 30-10-2012 by DJF90]

unionised - 30-10-2012 at 11:12

Quote: Originally posted by DJF90

@unionised: I was working off the top of my head without reference to any data. However thats not to say what I suggested won't work, it just needs a little tweaking. Performing the extraction with DCM might not work very well due to solubility reasons, but what about other organic solvents; ethyl acetate springs to mind, as does the use of chlorofom-ipa (7:3 might be appropriate in this case) - a well known solvent mixture for extraction of highly water soluble organics. Sorry to piss on your fire, asshole.

[Edited on 30-10-2012 by DJF90]

LOL again.

Bad language doesn't stop you being wrong.
Since tartaric acid is very soluble in water it's unlikely that you will find an immiscible solvent with a usable partition coefficient.
For example, what springs to your mind isn't good enough: you need evidence so, for example, here is a page which gives the solubility of tartaric acid in ethyl acetate
http://www.biochemicaldiagnostics.com/pdffiles/um17psilocin....
The solubility is 1 mg/ml.
On the other hand, the solubility in water is about 1500 mg/ml.
From that we can estimate the partition coefficient as being about 1/1500.
If you had 100 ml of a solution of tartaric acid and you wished to extract half the acid with ethyl acetate, you would need 150 litres of solvent.

It's an oversimplification- not least because all the water would dissolve with that much solvent- but it does show that your idea is still utter nonsense.

Next time you see fit to work off the top of your head, find a better one.In particular, if you are about to post something on line, check with Google that you are not making a fool of yourself.

CHRIS25 - 31-10-2012 at 04:28

Well that was a pointless exercise in nothingness. Having filtered the potasssium chloride (white) The solution in the beaker was a yellowish colour of methanol (surgical spirit), and I began to heat it it on a hotplate for 5 minutes. the smell was pleasant but pungent - knocked me backwards. I decided to read about heating this stuff and read that it was highly flammable and dangerous fumes. So removed it from the heat. I had hoped that there was tartaric acid hidden in this somewhere - but do not know what to do now.

The Whole yellow solution has now evaporated into emptiness, a magical example of nothingness, not even one grain.......So what is this with the alchohol treatment and collecting the tartaric acid through evaporation.Anyone?

[Edited on 31-10-2012 by CHRIS25]

Hexavalent - 31-10-2012 at 08:15

Not being funny, but something I do sometimes is discard my product and keep the waste. Are you certain you've not done that this time?

CHRIS25 - 31-10-2012 at 09:30

Quote: Originally posted by Hexavalent

Not being funny, but something I do sometimes is discard my product and keep the waste. Are you certain you've not done that this time?

Hi there, no, I have actually thrown nothing away at all. I have the filtered white mass still in a filter, and the beaker full of NO(th)Ingn.3ss still sitting there with the Alchohol residue at the bottom where the dry tartaric acid should be.

Hexavalent - 31-10-2012 at 09:35

What have you filtered?

CHRIS25 - 31-10-2012 at 10:05

Yes, that's what came out the bottom, the alchohol a little yellow.

Testing for Potassium chloride Tartaric acid presence

CHRIS25 - 1-11-2012 at 04:56

Hallo, I have a filtered white crystaline mass which I believe is potassium chloride, but I want to know whether this really is KCL or whether it has any tartaric acid in it, it smells of surgical spirits, but I do not want to just throw it away and start again, I want to test so that I can learn and establish what has been happening. If someone could advise please.

vmelkon - 1-11-2012 at 09:53

1. Flame test for potassium
2. Dry your solution slowly to have large crystals. Check out the crystal structure.
3. Add to some baking soda and see if it fizzes (acid test)

CHRIS25 - 1-11-2012 at 12:20

Ok, thankyou. Right, I added white powder to sodium bicarbonate, it fizzed. Also that had a PH of 8. I then added some to distilled water. The KCL obviously did not dissolve, but the solution was PH3.

So the methanol idea does not work in the slightest. How then can I separate the KCL from the Tartaric acid. Simply add distilled water and filtrate I suppose? Why then did some suggest the alchohol method - it did not work.

[Edited on 1-11-2012 by CHRIS25]

Potassium chloride is supposed to be Soluble.....

CHRIS25 - 2-11-2012 at 03:44

Whatever I have does not dissolve. At least not noticeably. I passed de-ionized water through it twice and the PH of the water is 3, indicating tartaric acid. But the white mass does not dissolve, otherwise I would have not been able to get a clear solution from the filter. Now this white crystalline powder is supposed to be KCL with a solubility of the top of my head 200-280g per 100mLs. Coming from potassium bitartrate and mixed with HCl I don't see the logic here.

The original suggestion to isolate tartaric acid was via alchohol because KCL does not dissolve in alchohol but tartaric acid can be dried out after filtration definitely does not work at all.

I am sure there is a logical explanation to all this, but I can not see it. I really need some help.

CHRIS25 - 8-11-2012 at 06:57

I have an unknown product which was supposed to be Tartaric acid crystallizing out of solution as the solution was left to evaporate over many days. This was what I did:

CaCo3+C4H5KO6 gives C4H4CaO6+CH4K2O6+h2O+CO2: Then:

CaCL2+CH4K2O6 gives2KCl+CH4CaO6: Then:

H2SO4+C4H4CaO6 gives CaSO4+C4H6O6

Method: 250mLs of warm water and added cream of Tartar, potassium bitartrate and dissolved. Then:
Added 15g Calcium carbonate. Then:
Filtered the calcium Tartrate precipitate and collected this into a beaker and added 25mLs of 98% sulphuric acid dissolved in 75mLs of de-ionised water. Then:
Waited until all the precipiate had settled to the bottom whilst still keeping the solution warm at around the 75c temperature. Filtered this precipitate and poured de-ionised water over it several times to collect the solution in the beaker. Allowed to cool and evaporate. But after three days I decided (after checking whether anything would decompose) to heat the solution gently for a number of hours and indeed I reduced the 300mLs to 60mLs and then removed from the heat and allowed to cool.

Observations about the the last part: The solution was very clear, after many hours of heating there was just water vapour coming off; then there suddenly appeared, after I left the solution un-attended for two hours, a room full of obnoxious gas, a foggy cloudy gas hanging, I had to ventilate the room quickly. The solution was now a light yellow colour and with white, fog like material settling at the bottom. I had earlier on, before heating noticed fine crystal-like structures that dissolved upon heating and then re-appeared upon cooling, but now that has all gone. Also the PH is now at this moment at 11, whereas when I first did a litmus test at the end of the whole double displacement, when I poured water over the calcium sulphate and collected the solution, and before the first heating, the PH was at 1. After trying to research out everything I can about tartaric acid and sulphuric acid I have no clue now what I have or why the PH change. Grateful for some insight or pointers please.

There is a part at the end of this video that is inconsistent, or at least, confusing. http://www.youtube.com/watch?v=Bt36jpk02Pk

He quotes in the video the following: "Filtrate while is still hot. Wash many times the sulfate that contains still quantities of tartaric acid and add the washing water to the philtrate. Let it evaporates for 6-10 days, than you will collect large crystals of tartaric acid".

If you follow this, as I did, and wash the calcium sulphate as he says you end up with huge amounts of wash water in your beaker, which is not shown on the video. Secondly a Filtrate IS the solution after the mass has been filtered, so what he mistakingly says next is to then wash all the wash water that you have just used to wash the Sulphate....which obviously I did not do. So I would be grateful if someone could clear up this confusing explanation please.

[Edited on 8-11-2012 by CHRIS25]

[Edited on 9-11-2012 by CHRIS25]

CHRIS25 - 17-11-2012 at 04:26

Quote: Originally posted by arsphenamine

It's slightly more complicated than expected.
The prep is a two pot reaction that relies on the lower solubilities of calcium salts.
Generate the calcium tartrate from cream of tartar and later acidify with sulfuric acid.

http://www.youtube.com/watch?v=Bt36jpk02Pk

After two failed attempts I decided to follow my own calculations according to the stoichemetry. Believing that he might have a reason for way off calcuulations I did the reaction a third time according to strict stoichemetry.

Working with 37.5g Potassium bitartrate
That would be 10g of CaCO3 not 15
11.1g of CaCl2 not 15
and then 9.8 mLs of H2SO4 and 15 mL water not 25mLs and 75 mLs water.

This third attempt also failed, the yield was practically the same as the last two times - about 0.2g of crystals still in solution - since evaporation will take at least two weeks especially if, after he suggests, you keep pouring water over the sulphate to flush out the tartaric acid in the filter, Any suggestions. I could buy the stuff tomorrow but I don't really want to give up on this one just yet.

CHRIS25 - 18-11-2012 at 01:24

Well, success! Spoke too early. I have a nice collection of tartaric acid crystals. I was fooled, because after I noticed crystals forming last week they disappeared after about 5 days - and the solution turned from a free flowing watery solution into a mildly thick viscous light cream solution with no sign of crystals and I assumed that this had failed. But after another two days a whole load of tartaric acid crystals appeared with almost complete evaporation.

Tartaric acid prep - OTC

ErgoloidMesylate - 7-5-2023 at 13:16

Quote: Originally posted by CHRIS25

Well, success! Spoke too early. I have a nice collection of tartaric acid crystals. I was fooled, because after I noticed crystals forming last week they disappeared after about 5 days - and the solution turned from a free flowing watery solution into a mildly thick viscous light cream solution with no sign of crystals and I assumed that this had failed. But after another two days a whole load of tartaric acid crystals appeared with almost complete evaporation.

That calcium method tends to form a nasty sludge. A cleaner prep, I have permission to detail, that guaranteed was not done by me, but was an adaption from a science journal. It uses 91% isopropyl, which may dissolve some of the ionic salts, but the precip should leave those in solution, and spit out the tartaric. It uses a vacuum (water aspirator vacuum is sufficient).

10 grams cream of tartar
50 ml distilled water

Stir to dissolve as much as possible.

10ml of concentrated hydrochloric acid
Stir for one minute

Vacuum to reduce volume to 10 ml

Should be yellowish at this point, and have some crystals floating around in it.

100 ml of 91% isopropyl to dissolve.

Anything that does not dissolve should be filtered out at this point.

Now use vacuum to reduce to 50 ml.
The tartaric acid should precipitate and should be filtered out.