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Paddywhacker
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Just speculating that it could be the difference in solubility between hot and cold for the two substances. NaCl dissolves just a little more when
heated wheras NaClO3 dissolves a lot.
Evaporate a mixed solution down to give crystals when hot, then filter and cool. Much more NaClO3 will crash out than NaCl. Make sense?
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Ebao-lu
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2 KClO4: boric acid can help to convert acid to amide. It is used to acylate alkylamines http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=v81...
and probably can be used with ammonium salts, that also not_important suggested once
| Quote: |
benzoic acid => ammonium benzoate => benzamide => aniline
the conversion to amide being done by heating with B(OH)3 catalyst in xylene, the water formed being azeotroped off. |
It can be a problem in your case to get rid of unreacted fat via acid-base extraction, because if you simply basify it to get salt, it will solubilize
your amide into emulsion. So better to use an excess of urea. You can get rid of urea/ its decomposion products by dissolving your amide in acetone
(other solvents may also suit, but biuret that is one of the decomposion products is comperatively soluble in ethanol).
ps: Urea dissolves it fat because it melts at 133
[Edited on 10-3-2009 by Ebao-lu]
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kclo4
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| Quote: | Originally posted by barbs09
Hi, This will probably be an easy one for some one.. For the purposes of extracting a crop of NaClO3 from a cell containing NaCl and NaClO3, two
methods are generally proposed 1, concentrating he solution untill the chlorate will crystallise out and 2, salting the chlorate out by the addition
of a salutation solution of NaCl.
My question is: since NaClO3 is over twice the solubility of NaCl for the same volume of water, why does the more soluble of the two salts precipitate
out?? I would have thought the least soluble salt (NaCl) would have crystallised out first. I cannot find a satisfactory answer anywhere.
Thanks in advance |
I think perhaps you are confusing NaClO3 with KClO3.
They normally add KCl to salt out KClO3 from a NaClO3 solution.
There are a lot of threads on this I believe, and I know there are a few very good websites about this.
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kclo4
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| Quote: | Originally posted by Ebao-lu
2 KClO4: boric acid can help to convert acid to amide. It is used to acylate alkylamines http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=v81...
and probably can be used with ammonium salts, that also not_important suggested once
| Quote: |
benzoic acid => ammonium benzoate => benzamide => aniline
the conversion to amide being done by heating with B(OH)3 catalyst in xylene, the water formed being azeotroped off. |
It can be a problem in your case to get rid of unreacted fat via acid-base extraction, because if you simply basify it to get salt, it will solubilize
your amide into emulsion. So better to use an excess of urea. You can get rid of urea/ its decomposion products by dissolving your amide in acetone
(other solvents may also suit, but biuret that is one of the decomposion products is comperatively soluble in ethanol).
ps: Urea dissolves it fat because it melts at 133
[Edited on 10-3-2009 by Ebao-lu] |
I don't think the Urea dissolved, instead it just melted and remained at the bottom.
I'd still like to find an easier way to get the glycerol from the fatty acids then to react it with NaOH, and then add an acid. I don't have any NaOH
at this moment and right now is not the best time for me to be buying it.
Thanks for the info on the boric acid! I didn't know that helped, perhaps that would allow the urea and the triglycerides to react. I wonder if
heating up boric acid with olive oil might free up the fatty acids by forming borogylcerin. I doubt it would since the boric acid is so weak but it
would be nice if it did.
Is there any other effective method of freeing the fatty acids from trigycerlides? such as something that would increase hydrolysis? boiling in a
solution of acid, perhaps? I've tried to make a soap with sodium carbonate but that failed miserably.
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dann2
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Hello,
Regarding the solubility of NaCl + NaClO3 it will depend on concentration of each salt and there mutual solubility. You can read up on the joys (and
joys they are) of mutual solubility here.
Salting out was actually used in industry to obtain a crop of Sodium Chlorate. Adding a concentrated solution of NaCl to a (suitably concentrated and
at a suitable temperature) solution of NaCl + NaClO3 caused some NaClO3 to fall out of solution.
Dann2
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barbs09
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Thanks for all your replies and dann2 special thanks for the link to the mutual solubility curve. This is off your Geocities-Cape Canaveral website I
believe? If it is you have added more to it since I last visited-good stuff by the way. Do you regularly update the site?
I thought by asking a chlorate question outside one of the umpteen dozen chlorate production strings/sites I ran the risk of getting flamed but I was
genuinely confused as to why the more soluble sodium chlorate could come out of solution before the less soluble sodium chloride. I believe my answer
will be found in the complicated looking mutual solubility diagram. It may take a few single malts to get there though 
Thanks all, AB
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not_important
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| Quote: | Originally posted by kclo4(much snipping)
Is there any other effective method of freeing the fatty acids from trigycerlides? such as something that would increase hydrolysis? boiling in a
solution of acid, perhaps? I've tried to make a soap with sodium carbonate but that failed miserably. |
Acid hydrolysis can be done, but is difficult in a non-industrial situation. Simply heating fats with water under pressure works too, and again isn't
the easiest at home. Also remember that the acid catalysed hydrolysis is reversible, use an excess of water and all that.
Sodium carbonate will work, but it is slow. The CO2 of the carbonate is slowly released, actual boiling helps sweep it away in the steam. But it
takes hours to go to completion, and you do need to use an excess of Na2CO3. You need good mixing, the steam helps with that but mechanical stirring
usually is needed.
The direct route to amides should work, although again time and good stirring are likely needed. A small amount of NH4Cl might help, functioning as an
acid catalyst.
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Ebao-lu
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why not to purchase a piece of soap? there should be a sodium stearate soap, without fragrances, it is usually brown. Tar soap is also usualy sodium
salt. Boric acid can surely catalyse the hydrolysis of fat via same mechanism lined out in the link, but a'm not sure that the rate of reaction will
be fine, besides fat is immiscible with water. Glycerol should also be sold in pharmacies.
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Sedit
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I have recently taken a fondness to electrochemistry and since im just starting to learn how to effectively use a divided cell. Well my question is
what one of the products may be.
Table salt is the electrolyte, cell is partioned with unglazed clay pot. The electrodes at this point where nothing more then Galvanized steel. PH
indicator showed the inside of the pots PH jumped right away. Both solutions remained clear and the cell was only run for maybe a half an hour or so.
So after getting a few mesurements on current ect I got ready to clean it and start something else. When the two clear solutions are mixed Something
white with a slight green tinge precipitates. Any idea what it is?
Basicly its just two zinc electrodes with a NaCl electrolyte.
Just woundering so i can get my head around the normal workings of a divided cell.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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hissingnoise
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I would suggest some reading on electrolysis---the cell you describe will simply waste your time and dissolve your anode.
The green precipitate is an anode-metal chloride.
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Sedit
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I know a decent amount about electrolysis thank you for the suggestion though.
Waste of time? Nope not at all I got the information I was after about how much current was going through ect. It had no real purpose other then
making sure the power source was functioning properly and the electrodes where used for nothing more then opportunity alone. I highly doubt it is any
metal chloride being as zinc chlorides would be soluble in the solution. Both solutions where clear befor being mixed and precipitated when mixed.
Its just a matter of curiosity what is happening when they are mixed.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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hissingnoise
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| Quote: | Originally posted by Sedit
I know a decent amount about electrolysis thank you for the suggestion though. |
Sedit, with all due respect, your questions on the subject suggest otherwise.
The most elementary reaction in brine electrolysis is dissolution of active anodes as their chlorides.
It's the very first thing one learns. . .
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Sedit
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And the solution is clear. There is no doubt that the Chloride was generated but it precipitates when added to the other partion. The Chloride is
reacting with what is at the cathode partion and precipitating a very light green fluff. I am under the assumption that at the cathode is NaOH and
Zn(OH)2. This is reacting with the chloride to produce ...? NaCl + ??
You see what Im getting at here?
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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hissingnoise
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In a partitioned cell, metal ions will accumulate in the cathode compartment raising pH, while chloride and hypochlorous ions in the anode compartment
will lower pH.
Mixing the basic and acidic solutions will precipitate the metal chloride + some hypochlorite. . .
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Sedit
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Im leaning toward hypochlorites and that was my original hunch thats why I was asking. All ZnCl i have ever made from reactions with hydrochloric have
been soluble in H2O yet the precipitate was compleatly non soluble so there is no chance of it being metal chloride because that is highly soluable in
H2O.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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hissingnoise
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Hypochlorite formation would be negligible because once formed the greater part of the chlorine would react directly with the active anode.
As for salt solubilities, your electrolyte is already saturated with NaCl. . .
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Sedit
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True being that ZnCl2 is more soluble then NaCl its possible that the precipitate is just salt with some hypochlorite contamination possibly
explaining the pale green color. Only way to be 100% possitive would be to reproduce it under more formal conditions and test what I precipitates but
its not to important to me so it may be a while.
Knowledge is useless to useless people...
"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the
fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story
before."~Maynard James Keenan
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497
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Are lactones able to form bisulfite adducts? Somehow I doubt it because I've searched and haven't found anything mentioning it.. But I wanted to make
sure.
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not_important
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Lactones are esters, not noted for form bisulfite adducts.
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Intergalactic_Captain
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Are there any uses for carbodiimide peptide coupling reagents aside from making LSD? My combichem group is currently working towards a small
tripeptide library and I've been stuck with all the research - From what I've read, it seems that activation of carboxylic acids is quite general
(with carbodiimides, DIC in our case). In particular, our scheme for coupling the first AA (fmoc-ala) to the (wang) resin involves DIC/DIPEA
(conditions currently being optimized).
Considering this is basically just an accelerated esterification reaction (wang resin is a polystyrene/divinylbenzene polymer functionalized with a
benzyl alcohol linker), I'm wondering about the general applicability of coupling a carboxylic acid to other substrates, in particular the preparation
of methyl esters for use as methylating agents (dimethyloxalate in particular, PTSA if it's even possible, ...) avoiding the necessity of forming the
acid chloride. DIC is way out of my price range, but its preparation by way of diisopropylurea and HgO is not.
If you see me running, try to keep up.
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marksev1
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fractional distillation question
Hello everybody! Which fractional column would you advise me (vigreux or something different), and more importantly how long, 300-400mm or more, for
effectivly distilling ethanol from denaturated alcohol (don't know yet which "contaminants" are present in the mixture with ethanol). Cause i would
like it pretty nontoxic for some extractions of some medicinal plants and so on..
There would be an easier way of just buying some vodka and distilling it but it wouldn't be such a challange. Thanks for the answers
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DJF90
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Perhaps there is another solvent you could used for your extractions. If you provide details of what you intend to extract and from what, then we may
be able to tell you which solvent(s) are best. It's possible that IPA will be suitable for your extraction, and this is available in 70% and 99%
concentrations OTC. Again, I cant be sure unless you tell me what you intend to extract.
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marksev1
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Yes, IPA is also a good choice, but i also don't know which impurities are in the more cheaper technical IPA in my country, if methanol is the case,
distilling would be an easier task because of the larger difference in boiling points. Here is a monograph on residual solvents in pharmaceutical
products:
http://lib.njutcm.edu.cn/yaodian/ep/EP5.0/05_general_texts/5...
(class 3 solvents would probably be good)
Btw, are spiral fractional coulumns more effective than vigreux...i've read somewhere that for the vigreux the HETP is about 10cm and for spiral
column it would be about 3cm, making it more effective...but i also read that metal spirals are even more efective, so which material could be used
for the spiral, perhaps stainless steel (just how inert is the chromium oxide coating present on stainless steel)? Some inert metal like platinum
would probably be the best choice, but it is costly big time, so i would need a cheaper alternative that would also be quite sufficient.
Does anybody maybe know of a book of qualitative analysis of natural products?
Concerning what would i like to extracted, different things from different plants, starting from caffeine,piperine, atropine, quinine, nicotine,
carvone,limolene,safrol,amygdalin,ginkolides,coumarines,menthol ...for more volitale things i would use steam distillation.
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querjek
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I've got some sodium formate and H2SO4 and would like some concentrated formic acid. Is it enough to simply distill a mixture of the two around 101
degrees C or should I add water?
it's all about chemistry.
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not_important
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In the presence of strong acids and/or heat formic acid decomposes into water and carbon monoxide; even pure +90% formic acid slowly decomposes so
storage containers need pressure relief to prevent explosions. You must use dilute acid, slowly add it to a solution of the formate, always have an
excess of format, and keep it cool. When finished, chill and filter off the hydrated sodium sulfate, the fractionate to get about 70% formic acid.
Supposedly it can also be had by mixing sodium formate and bisulfate and distilling under vacuum, but I've no details on that.
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