bluamine
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How can i percipitate a Na2S2O3/Na2S out of its aquous solution?
Hi guys!
I am planning to produce some sodium sulfide, & i have (finally) read about a method to produce sodium thiosulfate, by boiling sulfur in a sodium
hydroxide solution, which produces also some sodium sulfide as a byproduct. I would like to know what's the perfect solvent to use to percepetate out
the mixture out of solution? i thought about using ethanol but i'm not sure it is the best option
I need your help
[Edited on 11-4-2017 by bluamine]
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ZeroHour
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I'm interested in this reaction as well, to produce sodium thiosulfate for use as photographic fixer.
As far as I know a common method to precipitate salts out of solution is to cool the solution down to crash out the salts.
Wikipedia lists the solubility of sodium thiosulfate as negligible in ethanol, so I think that would be another route.
Would it be possible to recrystallize the produced mixture of sodium sulfite and sodium thiosulfate in order to obtain a purer sample of sodium
thiosulfate?
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Derek McOlund
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I think I have the solution to your problem (pun intended).
Anyway Na2S2O3 is more than 3 times more soluable at 100C than at 20C, collect the crystals from your reaction between NaOh and S.
Calculate how much Na2S2O3 you've got in the crystals.
Add 100mL boiling water to the amount of crystals that contains 230g Na2S2O3, filter out the Na2S and let the solution cool to room temperature.
Then you'll have about 160g precipitated sodium thiosulfate with some sodium sulfide contamination. Repeat the process, and in the end you'll have
nearly pure sodium thiosulfate.
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Aqua-regia
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"I am planning to produce some sodium sulfide, & i have (finally) read about a method to produce sodium thiosulfate, by boiling sulfur in a sodium
hydroxide solution, which produces also some sodium sulfide as a byproduct. "
No, this methode is wrong. Prepare NaOH solution and share it 50-50%. One of them saturate with SO2 and pour into the reserved NaOH solution. You
get Na2SO3 solution. Mix wet (with etOH) fine grinded sulfure more than stochiometric into this solution, and boil . Filter the unreacted S and
evaporate the clear solution. You get pour Na2S2O3x 5H2O . It is no Na2S byproduct.
NaOH+SO2 ——> NaHSO3
NaHSO3+NaOH ——> Na2SO3+H2O
Na2SO3+S+5H2O ——> Na2S2O3∙5H2O
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bluamine
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Quote: Originally posted by Aqua-regia  |
No, this methode is wrong. Prepare NaOH solution and share it 50-50%. One of them saturate with SO2 and pour into the reserved NaOH solution. You
get Na2SO3 solution. Mix wet (with etOH) fine grinded sulfure more than stochiometric into this solution, and boil . Filter the unreacted S and
evaporate the clear solution. You get pour Na2S2O3x 5H2O . It is no Na2S byproduct.
NaOH+SO2 ——> NaHSO3
NaHSO3+NaOH ——> Na2SO3+H2O
Na2SO3+S+5H2O ——> Na2S2O3∙5H2O
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Keep in mind that I'm interested in making sulfide & not thiosulfate
This is the equation I found on the link below:
6 NaOH + 4 S → 2 Na2S + Na2S2O3 + 3 H2O
https://en.m.wikipedia.org/wiki/Sodium_thiosulfate
Now I read somewhere that if we add an excess sulfur we would have Na2S5 instead of thiosulfate. That could be interesting but I don't know what
should the equation become in this case!
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j_sum1
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FWIW
http://www.prepchem.com/synthesis-of-sodium-sulfide/
http://www.prepchem.com/synthesis-of-sodium-thiosulfate/
These might be useful.
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bluamine
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I found that iron reaction with sulfur doesn't give a good yeald. However I have some aluminum dust (which is somehow contaminated with ground glass!)
So I will try soon to react it with sulfur since some guys here said it can be much more efficient to produce H2S
Anyway the point is that I found this method (NaOH & S) easier, even the purification I think
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Aqua-regia
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Sorry i was disconcentrated . If you need Na2S, the procedure is also the same, but generate and saturate your 1/2 vol. NaOH sol. with H2S gas
instead SO2.
NaOH + H2S → NaHS + H2O
NaHS + NaOH → Na2S + H2O
The best H2S source:
a) heat mixed candle wax with sulfur
b) buy OTC lithopon in the hardware store (it is white pigment ZnS+BaSO4)
and destroying with muriatic acid:
ZnS+2HCl = H2S+ZnCl2
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bluamine
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| Quote: Originally posted by Aqua-regia | Sorry i was disconcentrated . If you need Na2S, the procedure is also the same, but generate and saturate your 1/2 vol. NaOH sol. with H2S gas
instead SO2.
NaOH + H2S → NaHS + H2O
NaHS + NaOH → Na2S + H2O
The best H2S source:
a) heat mixed candle wax with sulfur
b) buy OTC lithopon in the hardware store (it is white pigment ZnS+BaSO4)
and destroying with muriatic acid:
ZnS+2HCl = H2S+ZnCl2
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I don't have access to lithopon
It's interesting that I can use candle wax (paraffin) but I need to know the amount I must use since I don't know the exact formula of this compound
& the equation of this reaction
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Aqua-regia
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Lithopone source in Europe:
http://www.malstoff.de/shop/108/Pigmente-ab-1000-g/2912/Pigm...
in US http://shop.kremerpigments.com/en/search?sSearch=lithopone
candle wax + sulfur 50-50% mix, just heating. evolves lot of H2S. Pay attention H2S is very nasty. Work in outside far enough of neighbors, unless
you want become unexpected visitors (police)
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clearly_not_atara
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I am frankly shocked that you've all preferred a method using H2S gas instead of simply refluxing sulfur with NaOH as the author originally proposed.
The original method is far safer and easier and while the yield is not ideal it's not clear why anyone would want to make large amounts of such a
toxic material as sodium sulfide.
In any case, Na2S is the least soluble salt among the three (NaOH, Na2S2O3, Na2S) and will precipitate first when the solution (produced from NaOH +
S) is concentrated and cooled. All you need to do is remove water, preferably under vacuum, as heating may cause the product to oxidize.
Perform all reactions in a good hood as while H2S should not be released from alkaline solution it's not exactly worth the risk.
Once the product is obtained, the mother liquor can be detoxified with H2O2 for disposal. Seriously, there's no reason to put any more fucking-about
into this reaction than is absolutely necessary.
Aqua-regia is a dangerous idiot.
| Quote: | | a) heat mixed candle wax with sulfur |
THIS REACTION CAN KILL YOU
[Edited on 24-4-2017 by clearly_not_atara]
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bluamine
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| Quote: Originally posted by Aqua-regia |
candle wax + sulfur 50-50% mix, just heating. evolves lot of H2S. Pay attention H2S is very nasty. Work in outside far enough of neighbors, unless
you want become unexpected visitors (police) |
Wow! That would be interesting!
I never sealed with H2S, so allow me to ask you why can it be this dangerous outside? Does it seem like a big amount of smoke?!
I want also to know if I must melt paraffin
| Quote: Originally posted by clearly_not_atara | I am frankly shocked that you've all preferred a method using H2S gas instead of simply refluxing sulfur with NaOH as the author originally proposed.
The original method is far safer and easier and while the yield is not ideal it's not clear why anyone would want to make large amounts of such a
toxic material as sodium sulfide.
In any case, Na2S is the least soluble salt among the three (NaOH, Na2S2O3, Na2S) and will precipitate first when the solution (produced from NaOH +
S) is concentrated and cooled. All you need to do is remove water, preferably under vacuum, as heating may cause the product to oxidize.
Perform all reactions in a good hood as while H2S should not be released from alkaline solution it's not exactly worth the risk.
Once the product is obtained, the mother liquor can be detoxified with H2O2 for disposal. Seriously, there's no reason to put any more fucking-about
into this reaction than is absolutely necessary.
Aqua-regia is a dangerous idiot.
| Quote: | | a) heat mixed candle wax with sulfur |
THIS REACTION CAN KILL YOU
[Edited on 24-4-2017 by clearly_not_atara] |
Please don't insult anyone, we are all here to learn & help others learning
Well, Na2S itself is not very useful & I think the main use of this chemical is in Kraft process!
But I will try to use it mainly to produce other sulfides (the most other sulfides are insoluble) like PbS which can be used for example as a black
pigment instead of magnetite or carbon which have their disadvantages (the first one attracts some metals including iron, which can be considered as a
disadvantage, & the second one is flammable, although even PbS is toxic anyway)
[Edited on 25-4-2017 by bluamine]
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bluamine
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This is a link to another topic about Aqua-Regia's route
http://www.sciencemadness.org/talk/viewthread.php?tid=11996
[Edited on 25-4-2017 by bluamine]
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woelen
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The method of clearly_not_atara is not practical and does not lead to satisfactory results. It is very messy. You end up with a very complicated mix
of thiosulfate, sulfide, polysulfides, hydroxide and possibly some sulfite as well. You are a very good boy if you can isolate pure Na2S from this.
Keep in mind that Na2S is very hygroscopic and quite air-sensitive.
If you want pure Na2S, then bubbling H2S through NaOH-solution indeed is the way to go, but as mentioned already, you must know the risks and be
capable of dealing with them properly. H2S is very toxic and it may knock you down easily, when released in somewhat greater quantities (user Klute
has written on sciencemadness about his frightening experience with H2S a few years ago, use the search engine to find that thread). If you bubble
this gas through a solution of NaOH then you must use a good fumehood, or work outside on a breezy day. If you don't want the stink, then a good way
of getting rid of not absorbed gas is leading it into a flame. It burns to SO2 and water. H2S is flammable, but to be sure, I would use an external
flame, because flames of H2S itself tend to go out easily. SO2 also is toxic, but much less so than H2S and if you do this outside, then you do not
stink up the neighborhood. SO2 smells more like burnt fireworks or some kinds of matches, albeit not exactly so. Anyway, it is much less alarming than
the smell of H2S.
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bluamine
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| Quote: Originally posted by woelen | The method of clearly_not_atara is not practical and does not lead to satisfactory results. It is very messy. You end up with a very complicated mix
of thiosulfate, sulfide, polysulfides, hydroxide and possibly some sulfite as well. You are a very good boy if you can isolate pure Na2S from this.
Keep in mind that Na2S is very hygroscopic and quite air-sensitive.
If you want pure Na2S, then bubbling H2S through NaOH-solution indeed is the way to go, but as mentioned already, you must know the risks and be
capable of dealing with them properly. H2S is very toxic and it may knock you down easily, when released in somewhat greater quantities (user Klute
has written on sciencemadness about his frightening experience with H2S a few years ago, use the search engine to find that thread). If you bubble
this gas through a solution of NaOH then you must use a good fumehood, or work outside on a breezy day. If you don't want the stink, then a good way
of getting rid of not absorbed gas is leading it into a flame. It burns to SO2 and water. H2S is flammable, but to be sure, I would use an external
flame, because flames of H2S itself tend to go out easily. SO2 also is toxic, but much less so than H2S and if you do this outside, then you do not
stink up the neighborhood. SO2 smells more like burnt fireworks or some kinds of matches, albeit not exactly so. Anyway, it is much less alarming than
the smell of H2S. |
This is a link to the topic you were talking about :
https://www.sciencemadness.org/whisper/viewthread.php?tid=10...
As well, the lion below shows the toxicity of H2S with some details
https://www.osha.gov/SLTC/hydrogensulfide/hazards.html
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Rhodanide
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| Quote: Originally posted by woelen | | SO2 also is toxic, but much less so than H2S and if you do this outside, then you do not stink up the neighborhood. SO2 smells more like burnt
fireworks or some kinds of matches, albeit not exactly so. Anyway, it is much less alarming than the smell of H2S. |
Ahhh, SO2. Good times, good times.
The first time I ever threw up from any chemical was when I got a dangerously large whiff* of SO2 which was lingering in a container. I'm probably
lucky I didn't suffocate afterwards. I really was an idiot, but hey, I was much younger.
*Wasn't a whiff, I INHALED that shit and I don't know why. I wasn't familiar with "Wafting". Wish I was.
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Aqua-regia
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THIS REACTION CAN KILL YOU
I would like to draw attention in this debat: The problems and hazards involved in working with chemical substances are self-evident. That reasons
practical chemistry is often dangerous. I warned blueamine of the danger we face. (H2S very nasty)
This is the point.
H2S generating with Candle wax + sulfur i guess over 200 years well known methode. Not knowing or not follow up on things i's no excuse. Sorry
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bluamine
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| Quote: Originally posted by Aqua-regia | THIS REACTION CAN KILL YOU
I would like to draw attention in this debat: The problems and hazards involved in working with chemical substances are self-evident. That reasons
practical chemistry is often dangerous. I warned blueamine of the danger we face. (H2S very nasty)
This is the point.
H2S generating with Candle wax + sulfur i guess over 200 years well known methode. Not knowing or not follow up on things i's no excuse. Sorry
|
What I should know before is the equation & the yield of this reaction! because it sounds to be a very easy alternative of aluminium/iron sulphide
process..
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Aqua-regia
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Forget the iron sulphide. Very bad yielding the homemade one. Al dust + fine grinded S works very well. Using sulfur in excess not stochiometric,
cause a part of S burning out. If you do this, do in outside far of people again! The gained product is extremly higroskopic, storage in good sealed
container.
As i reported to you, buy online lithopone. This is not harmful, cheap can generating with this really good controlled H2S stream If you have
furnace or can making a lot of heat with carbon + oxygen, study the old Leblanc process without chalk:
https://en.wikipedia.org/wiki/Leblanc_process
Good luck
[Edited on 25-4-2017 by Aqua-regia]
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AJKOER
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If one can buy a ZnS product, try adding hot aqueous NaOH:
ZnS + 2 NaOH = Zn(OH)2 + Na2S
I have seen this reaction written in both directions, but there is a source stating the reaction as above. See "University Chemistry," Volume 2, by C.
Parameshwara Murthy, page 671, link:
https://books.google.com/books?id=vsFrTGp4y-AC&pg=PA607&lpg=PA607&dq=ZnS+%2B+2+NaOH+%3D+Na2S+%2B+Zn(OH)2&source=bl&ots=RnhoKLxhmn&
amp;sig=GIVR3VGdd4UhWr_8ZKF4VrI97eE&hl=en&sa=X&ved=0ahUKEwj2xpuaiMHTAhVCLyYKHV4qC-8Q6AEIIjAE#v=onepage&q=ZnS%20%2B%202%20NaOH%20%3D%20
Na2S%20%2B%20Zn(OH)2&f=false
But not an excess of NaOH as:
Zn(OH)2 + 2 NaOH = Na2(ZnO2) + 2 H2O (same source)
For background on ZnS, see http://zinc.atomistry.com/zinc_sulphide.html and Na2S see http://sodium.atomistry.com/sodium_monosulphide.html .
Note: Atomistry is a copyrighted historical compilation of old chemical journals, absent the date, author and name of the journal whose copyright has
since expired.. Exercise caution on possibly very dated material.
[Edited on 26-4-2017 by AJKOER]
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Aqua-regia
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It seems also a possible choice to get the Na2S, but is more academic im my opinion. I much doubt that this way is optimal for preparative, because
the Zn(OH)2 is slightly soluble in water, and likewise question the good filtrating property of this precipitate. Hydroxide often occuring a big
suck in filtration process. If the purity does no matter, this is the most safest prep for blueamine.
[Edited on 26-4-2017 by Aqua-regia]
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AJKOER
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Accidentally can across a new aqueous procedure to possibly convert sulfate to sulphide in the presence nitrate with an Aluminum/Copper galvanic
couple:
To quote:
"aluminium/copper galvanic couple was so energetic that it reduced the nitrate in
the water to ammonia and some of the sulphate to sulphide. Both of these ions are
highly corrosive to copper. It was clear from the composition of the waters in
which Rosette corrosion was occurring that there was not an absolute level of
nitrate and sulphate at which problems arose, rather it was the ratio of the
compounds that was important."
Source: Causes of copper corrosion in plumbing systems fr/r0007 - Foundation for Water Research
Link: https://www.google.com/url?sa=t&source=web&rct=j&...
Should be an interesting experiment with say readily available KNO3 and MgSO4 in contact with Al metal in an aqueous Cu(l) salt.
Success would be evident as MgS decomposes in water to Mg(OH)2 and H2S.
------------------------------------
My rough speculative take on the underlying mechanics given that there appears to be little documentation in this area:
First, the role of the nitrate here is to provide a source of NH4+/NH3 (see, for example, my discussion at https://www.sciencemadness.org/whisper/viewthread.php?tid=29... ).
Next, the Al/Cu couple provides a current (see https://www.google.com/url?sa=t&source=web&rct=j&... and also https://www.ncbi.nlm.nih.gov/pubmed/11866069 ):
Al/Cu Galvanic Couple ---) e-
e- + nH2O ---) e-(aq)
H2O = H+ + OH-
H+ + e-(aq) ---) .H
NH3 + .H ---) NH4+ + e-(aq) (see https://www3.nd.edu/~ndrlrcdc/Compilations/HAtom/H_116.HTM )
NH4+ + H2O = NH3 + H3O+
NH4+ + OH- = NH3 + H2O
And the reducing hydrogen atom radical is cycled and more available (longer half-life).
[Edited on 27-4-2017 by AJKOER]
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bluamine
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| Quote: Originally posted by AJKOER | Accidentally can across a new aqueous procedure to possibly convert sulfate to sulphide in the presence nitrate with an Aluminum/Copper galvanic
couple:
To quote:
"aluminium/copper galvanic couple was so energetic that it reduced the nitrate in
the water to ammonia and some of the sulphate to sulphide. Both of these ions are
highly corrosive to copper. It was clear from the composition of the waters in
which Rosette corrosion was occurring that there was not an absolute level of
nitrate and sulphate at which problems arose, rather it was the ratio of the
compounds that was important."
Source: Causes of copper corrosion in plumbing systems fr/r0007 - Foundation for Water Research
Link: https://www.google.com/url?sa=t&source=web&rct=j&...
Should be an interesting experiment with say readily available KNO3 and MgSO4 in contact with Al metal in an aqueous Cu(l) salt.
Success would be evident as MgS decomposes in water to Mg(OH)2 and H2S.
------------------------------------
My rough speculative take on the underlying mechanics given that there appears to be little documentation in this area:
First, the role of the nitrate here is to provide a source of NH4+/NH3 (see, for example, my discussion at https://www.sciencemadness.org/whisper/viewthread.php?tid=29... ).
Next, the Al/Cu couple provides a current (see https://www.google.com/url?sa=t&source=web&rct=j&... and also https://www.ncbi.nlm.nih.gov/pubmed/11866069 ):
Al/Cu Galvanic Couple ---) e-
e- + nH2O ---) e-(aq)
H2O = H+ + OH-
H+ + e-(aq) ---) .H
NH3 + .H ---) NH4+ + e-(aq) (see https://www3.nd.edu/~ndrlrcdc/Compilations/HAtom/H_116.HTM )
NH4+ + H2O = NH3 + H3O+
NH4+ + OH- = NH3 + H2O
And the reducing hydrogen atom radical is cycled and more available (longer half-life).
[Edited on 27-4-2017 by AJKOER] |
Wow! that's interesting! but I really want to react wax with sulphur & need some more details about the amount of gas produced compared with the
amount of wax plesae
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Aqua-regia
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This is very simple 50% fleck of candle wax + 50% sulfur powder mix and melt in a suitable old (big suck after that cleaning!) flask. If you heating
the mixture will melt and and will be dark end darker while evolving H2S The reaction able to turning violent that reason heat it very carefull and
regurarly. Thats the point. I dont have any idea how experienced you are and what kind of lab equipment do you have.(I guess you are beginner and
unexperienced without good lab stuff ) That reason i warn you again, H2S is very nasty, you can kill yourself with H2S gas. I advise you try it first
in very very small amount with test tube outside to collect some impression. By the way H2S generating in lab using metal sulfides with diluted
acid. This is safer and you can hold the process better under controll.
[Edited on 29-4-2017 by Aqua-regia]
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bluamine
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| Quote: Originally posted by Aqua-regia |
. By the way H2S generating in lab using metal sulfides with diluted acid. This is safer and you can hold the process better under controll.
[Edited on 29-4-2017 by Aqua-regia] |
honestly I remembred i already did this last experiment with some commercial vinegar when i was trying to clean the stuff i used to make some iron
sulphide & i smelled the gas rotten eggs like odor.. by the way i used also a NaOCl to get rid of unreacted iron & thus i smelled another
weird odor which i don't know how to describe..
anyway what i would like to know is what are the other final products? & does anyone of them contain sulphur? Because as you know it's very
important to have a good idea about the yield
Thanks
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