Sciencemadness Discussion Board
Not logged in [Login - Register]
Go To Bottom

Printable Version  
Author: Subject: Acetone plus sulphur plus NaOH
woelen
Super Administrator
*********




Posts: 6455
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 19-3-2013 at 00:12
Acetone plus sulphur plus NaOH


It is known fairly well that sulphur dissolves slightly in acetone. Not very much, but the effect is noticeable.

A funny reaction occurs, when also NaOH (or KOH) is added and some water. This leads to formation of a 2-layer system (salting out effect, acetone cannot be completely mixed with water in the presence of dissolved NaOH). The sulphur in this solution leads to formation of a brown/green compound with a very bad smell. For me, the formation of this brown/green compound is a riddle. It only is formed if ale three of NaOH, sulphur and acetone are present as well as a little water. Any idea what this compound can be?




The art of wondering makes life worth living...
Want to wonder? Look at http://www.oelen.net/science
View user's profile Visit user's homepage View All Posts By User
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
*****




Posts: 1986
Registered: 2-3-2011
Member Is Offline

Mood: No Mood

[*] posted on 19-3-2013 at 00:32


Probably quite a variety of different compounds. All three of these chemicals can react with any other. I guess the question is which reaction pathway would be fastest. The order of addition of the 3 reactants probably makes a significant difference also.

I suspect some acetone sulfonate may be forming, with conjugated bonding, at least in its tautomeric form.
View user's profile Visit user's homepage View All Posts By User
mayko
International Hazard
*****




Posts: 755
Registered: 17-1-2013
Location: Carrboro, NC
Member Is Offline

Mood: anomalous

[*] posted on 19-3-2013 at 06:06


I ran across the same thing; not sure what exactly is going on, but here's some discussion about it:

http://www.sciencemadness.org/talk/viewthread.php?tid=23236#...
View user's profile Visit user's homepage View All Posts By User
SteveJones
Harmless
*




Posts: 6
Registered: 22-12-2011
Member Is Offline

Mood: Stable

[*] posted on 19-3-2013 at 12:51


It could be that your forming a thiol; it's well known that one can form thiols by the addition of an organolithium or Grignard reagents (most commonly) to solid sulphur. After work up one obtains the protonated thiol.

The pKa of acetone is around 20 or so of the top of my head, the pKa of primary alcohols is around 16 or so, for thiols it will be even lower because sulphur is better able to stabilise a negative charge due to it's larger size and access to d-orbitals.

It might not be entirely unreasonable to guess that the hydroxide deprotonates a small quantity of acetone to generate the enolate, which then attacks the sulphur to give the thiol, which would more than likely be accounting for the awful smell you're getting
View user's profile View All Posts By User
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
*****




Posts: 1986
Registered: 2-3-2011
Member Is Offline

Mood: No Mood

[*] posted on 19-3-2013 at 13:12


Several elements react and disproportionate in the presence of aqueous base, including sulfur.

You can boil gardening-type sulfur with cement lime (calcium hydroxide) to form calcium thiosulfate and polysulfides:

5 Ca(OH)2 + 10 S --> CaS2O3 + 5 H2O + 4 CaS2

I wrote "CaS2" in the equation, but higher polysulfides are also formed, for example CaS3, CaS4, etc.
View user's profile Visit user's homepage View All Posts By User
madscientist
Super Moderator
*******




Posts: 962
Registered: 19-5-2002
Location: American Midwest
Member Is Offline

Mood: pyrophoric

[*] posted on 24-3-2013 at 18:52


How weird, I had just looked for the original thread on this, but it was apparently a casualty of a database error. I did this back in 2002, I think it was the third thread on the forum, and quite appropriately it was a tale of how I stunk up my entire neighborhood with that discovery. It got hot fast, turned dark, and began boiling, releasing the most intense, overpowering stench I have ever encountered. My guess is the sulfur is oxidizing the enolate, affording thiols derived from acetone, while the aldol chemistry throws a tar party.

I have no idea what I was trying to do, it seems so random now.

http://pipeline.corante.com/archives/2009/06/11/things_i_won...

I really doubt it's producing thioacetone, but it's vaguely relevant, and amusing.

Quote:
"Recently we found ourselves with an odour problem beyond our worst expectations. During early experiments, a stopper jumped from a bottle of residues, and, although replaced at once, resulted in an immediate complaint of nausea and sickness from colleagues working in a building two hundred yards away. Two of our chemists who had done no more than investigate the cracking of minute amounts of trithioacetone found themselves the object of hostile stares in a restaurant and suffered the humiliation of having a waitress spray the area around them with a deodorant. The odours defied the expected effects of dilution since workers in the laboratory did not find the odours intolerable ... and genuinely denied responsibility since they were working in closed systems. To convince them otherwise, they were dispersed with other observers around the laboratory, at distances up to a quarter of a mile, and one drop of either acetone gem-dithiol or the mother liquors from crude trithioacetone crystallisations were placed on a watch glass in a fume cupboard. The odour was detected downwind in seconds."




I weep at the sight of flaming acetic anhydride.
View user's profile View All Posts By User
Eddygp
International Hazard
*****




Posts: 834
Registered: 31-3-2012
Location: University of York, UK
Member Is Offline

Mood: Organometallic

[*] posted on 13-5-2013 at 09:17


I have remembered today about having read something about dissolving sulfur in acetone and adding NaOH, so I searched it and here it was. I am actually a bit interested in this reaction and, if the stench isn't too stench-y, I might do it once I have a slight idea about what it forms. I think that it might form some sort of complex substituting one of the hydrogens in acetone and complexing with a sodium cation, giving this product AND water too. What do you think?
Sorry for un-earthing this thread.




there may be bugs in gfind

[ˌɛdidʒiˈpiː] IPA pronunciation for my Username
View user's profile View All Posts By User
Adas
International Hazard
*****




Posts: 711
Registered: 21-9-2011
Location: Slovakia
Member Is Offline

Mood: Sensitive to shock and friction

[*] posted on 13-5-2013 at 12:10


Quote: Originally posted by Eddygp  
I have remembered today about having read something about dissolving sulfur in acetone and adding NaOH, so I searched it and here it was. I am actually a bit interested in this reaction and, if the stench isn't too stench-y, I might do it once I have a slight idea about what it forms. I think that it might form some sort of complex substituting one of the hydrogens in acetone and complexing with a sodium cation, giving this product AND water too. What do you think?
Sorry for un-earthing this thread.


The odor is very faint, not even close to what woelen described. I even find it a little pleasant. Go ahead and try it! :)




Rest In Pieces!
View user's profile Visit user's homepage View All Posts By User
DraconicAcid
International Hazard
*****




Posts: 2500
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline

Mood: Semi-victorious.

[*] posted on 13-5-2013 at 12:25


Quote: Originally posted by Adas  
Quote: Originally posted by Eddygp  
I have remembered today about having read something about dissolving sulfur in acetone and adding NaOH, so I searched it and here it was. I am actually a bit interested in this reaction and, if the stench isn't too stench-y, I might do it once I have a slight idea about what it forms. I think that it might form some sort of complex substituting one of the hydrogens in acetone and complexing with a sodium cation, giving this product AND water too. What do you think?
Sorry for un-earthing this thread.


The odor is very faint, not even close to what woelen described. I even find it a little pleasant. Go ahead and try it! :)


I've been told that before. Heck, I think I've even *told* people that before- few were foolish enough to believe me.




Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 6455
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 14-5-2013 at 01:24


The stench is not as bad as madscientist describes, but I find the smell unpleasant. It is quite strong to me, but in order to smell it I have to blow some of the vapor towards my nose by waving with my hands above the flask, containing the acetone, NaOH and water. You should not stick your nose in the flask!



The art of wondering makes life worth living...
Want to wonder? Look at http://www.oelen.net/science
View user's profile Visit user's homepage View All Posts By User
franklyn
International Hazard
*****




Posts: 2989
Registered: 30-5-2006
Location: Da Big Apple
Member Is Offline

Mood: No Mood

[*] posted on 15-5-2013 at 10:43


Perhaps this may help. Mercaptan is the older name for Thiol.
These compounds are known for their irrepressible odor.

Mercaptans & Derivative Chemistry
www.arkema-inc.com/literature/pdf/368.pdf

.
View user's profile View All Posts By User
Zyklon-A
International Hazard
*****




Posts: 1547
Registered: 26-11-2013
Member Is Offline

Mood: Fluorine radical

[*] posted on 29-5-2014 at 20:38


I found this reaction by mistake on woelen's site and used it to clean an old test tube that was caked with molten sulfur (thanks BTW woelen, dissolved the sulfur like a charm!)
Anyway, I didn't smell anything bad as far as I remember (it was several weeks ago), anyone have ideas as to why?




View user's profile View All Posts By User
Mildronate
National Hazard
****




Posts: 426
Registered: 12-9-2009
Member Is Offline

Mood: Ruido sintetico

[*] posted on 30-5-2014 at 02:09


1 step maybe aldol condensation and product react with sulfur?
View user's profile View All Posts By User
Σldritch
Hazard to Others
***




Posts: 127
Registered: 22-3-2016
Member Is Offline

Mood: No Mood

[*] posted on 11-1-2018 at 15:23


I have been looking for the answer to this on and of for some years now and i think i finally found it!
https://books.google.se/books?id=Mtth5g59dEIC&pg=PA523&a...

Page 518

Because i can not copy it, please excuse the at least ten inevitable spelling errors:
"If alkali metal polysulfides are added to a polar media like acetone, dimethylformamide, dimethylsulfoxide or alkali halide melts, the resulting solutions are colored. The color is due to the presence of polysulfides(1-) SSn-: the yellow green disulfide(1-), S2- (which corresponds to O2-): the blue trisulfide(1-), S3- (which corresponds to the ozonide, O3-); and the red tetrasulfide(1-), S4-."

[Edited on 11-1-2018 by Σldritch]
View user's profile View All Posts By User
Σldritch
Hazard to Others
***




Posts: 127
Registered: 22-3-2016
Member Is Offline

Mood: No Mood

[*] posted on 11-1-2018 at 15:26


For some reason i could not write further than that in a single post (why?) so here is the rest:

The stability of these anions decreases in the order: S3- > S2- > S4- .

And it goes on... Really intresting read!

It should be pretty obvious what is happening in this reaction now. Maybe im the only one that still cares about this but i thought i might as well post it.

[Edited on 11-1-2018 by Σldritch]
View user's profile View All Posts By User
Texium (zts16)
Super Moderator
Thread Moved
11-1-2018 at 15:29

  Go To Top