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CHRIS25
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Trying to dissolve Sulphur
Hallo, now I know that Sulphur is insoluble, and I read that you can dissolve sulphur with the help of carbon disulphide but this is not practical for
me.
I have a Half teaspoon of Sulphur powder on a stainless steel spoon, after it has melted I add one large flake of Potassium Hydroxide and wait until
that is melted, the spoon is then submerged into Hot, but not boiling, de-ionised water.
Apart from the very first attempt (which I have not been able to replicate) I get only about half strength solution of the Potassium Polysulphide,
there are bits of large undissolved sulphur left over in the water.
As i said the very first time I did this it worked, and apart from the temperature variance of the water, (since I can not control it precisely) I do
not know what can be improved. By the way, the amount of water is always 200ml to a half teaspoon sulphur and the same size flake of KOH is used each
time.
Can you suggest a more efficient way of doing this? or a tip?
Kind Regards
Chris.
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kristofvagyok
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Long ago when I had a problem with dissolution of sulfur, then I tryed out with organic solvents, like dichloroethylene, xylene, toluene, benzene,
petrol and alcohol. The most effinent was trichloroethylene, after xylene, toluene and everything else.
The problem with trichloroethylene is that it is carcinogen, toxic ect., the problem with xylene was, it has a high boiling point and it was difficult
to remove and the toluene had the same problem.
Afterall I used toluene, because it was enough good for my ideas.... But all the listed solvents are good.
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
"You can’t become a chemist and expect to live forever." |
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CHRIS25
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Hallo, yes thankyou, I saw already about Toluene, but did not want to complicate the process really. I have no idea how to use it or where to get it.
Thankyou Kristof.
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watson.fawkes
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What, exactly, are you trying to do? Dissolve
sulfur, or make some liver of sulfur?
Tip: Buy an electronic scale. An adequate starter one can be had for ~$20 - 30. For reference, something like this one from HF.
Tip 2: Keep a lab notebook. Record quantities. Since by your own account you're getting inconsistent results, you'll do far better to start being
quantitative.
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CHRIS25
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Ah, Hallo again, well thankyou for your suggestion. Yes you are right - I need to record everything. At the moment I have two lab books, one for the
equations and calculations and chemical inventory. the other for experiments. Unfortunately with this particular one I did not bother since one
flake into half teaspoon is, by its, very nature, not necessary to be "gram/molecular" accurate, and yes it is liver of sulphur.
Kind regards
Chris
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watson.fawkes
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The traditional methods for liver of sulfur all use fire. Perhaps the easiest is
to fuse sulfur with a potassium salt. KOH both work K2CO3. All you need is a small crucible and a propane torch. For small
amounts, a metal pipe cap should work fine.
Liver of sulfur has also referred to the calcium version of this, which is made with lime (quick or slaked) or chalk (the carbonate). For coloring
metal, the sodium version has also been used.
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CHRIS25
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Quote: Originally posted by watson.fawkes  | Perhaps the easiest is to fuse sulfur with a potassium salt.
Hallo, Ok I will but I noticed and was a bit afraid of heating the sulphur and KOH too much since there was some spitting and assumed a mini explosion
was about to happen. I had read somewhere about the volatile nature of sulphur when heated too much.
Liver of sulfur has also referred to the calcium version of this, which is made with lime (quick or slaked) or chalk (the carbonate). For coloring
metal, the sodium version has also been used. |
Good idea, I might well give this a try. I made my own calcium carbonate a few weaks ago by collecting white seashells from the beach, Hesitant to
buy the chalk board stuff since a lot of it is now made with magnesium carbonate so I read, and had no way to tell the difference. hence the seashell
outing. Thankyou for that tip though with the calcium hydroxide.
Kind regards
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watson.fawkes
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| Quote: Originally posted by CHRIS25 | | I will but I noticed and was a bit afraid of heating the sulphur and KOH too much since there was some spitting and assumed a mini explosion was about
to happen. I had read somewhere about the volatile nature of sulphur when heated too much. |
Well, then don't
heat the sulfur too much. I'm serious. The melting point of sulfur is will within the range of an ordinary candy thermometer. (Don't use that
thermometer afterwards for candy, of course until it's rocket candy.)
Any of these reactions are going to sputter because you're releasing SO2. If you're making enough that such spattering is a problem just
use mechanical means to contains the spatter. Using a high-form crucible is the easiest, particularly if you're using iron pipe parts.
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CHRIS25
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Thankyou, I can only get crucibles from England, or USA. Postage is a pain. I'll keep to the steel. But I am only making as required anyway, no
more than 100ml solution each time. Although what did you mean by a metal pipe cap? No clue what that is.
Regards
Chris
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watson.fawkes
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Well, where are you then? Almost
everywhere in the world has pottery or mine prospecting, both activities from which to obtain crucibles.
Here's some information on what a pipe cap is.
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CHRIS25
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Hallo, In Ireland I found only the stainless steel and porcelain crucibles - way Over Priced and pretty much inadequate I think anyway. In USA I can
get hold of high temp, (used for Gold and silver), the Graphite and fused silica for a very good price, fair and honest. I obviously live in Ireland
where even the websites malfunction, everyone I know shops abroad die to the lack of transparency and unfairness in this country.
Pottery shops you say? I will have to visit one locally and see what temperature they can be heated up to, but how inertl is pottery I wonder? I will
look that up. thankyou for the Pipe cap link by the way.
Kind regards
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watson.fawkes
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| Quote: Originally posted by CHRIS25 | | In USA I can get hold of high temp, (used for Gold and silver), the Graphite and fused silica for a very good price, fair and honest.
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You are way overthinking all this. Part of it is that you aren't thinking at all quantitatively. The
quantity that's relevant is temperature. So I'm assigning you some homework. (1) What's the melting point of sulfur? (that will be bit below your
reaction temperature) (2) What's the firing temperature of "cone 06" clay? (that's a low fire clay used for, say, flower pots). (3) What's the
softening point of borosilicate glass?
All three of these questions have answers readily available with a bit of internet searching. Once you have the number, answer the essay question: (4)
Will either of these materials will work for making liver of sulfur?
Since by now you must have obtained your lab notebook (cough!), record these numbers for future use, because given your interest it seems likely
you'll want to refer to them again. | Quote: Originally posted by CHRIS25 | | Pottery shops you say? I will have to visit one locally and see what temperature they can be heated up to, but how inertl is pottery I wonder?
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The standard little lab crucibles are nothing other than slip cast porcelain; nothing magic. If pottery
weren't inert to many things, it would never have been useful.
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AndersHoveland
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Sodium sulfite, Na2SO3, solutions can also "dissolve" sulfur, but of course this is a chemical reaction producing thiosulfate. But the sulfur can be
precipitated out again by acidifying the solution.
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CHRIS25
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Hi, watson Fawkes, well thanks for the homework, last time I did homework was at my Photography diploma! Anyway to answer your questions: Sulphur
melts at 115 centigrade. Firing temp of clone 06 clay was not consistent, so I averaged everything to two results: Between 1798 and 1855 F and 1828
to 2088F, and finally Borosilicate glass softens at 820 F. Well that's the test tube I presume.
But while this was helpful and interesting, and yes I mean that, my concerns come with reactivity of compounds and liquids with their holding
materials, so one would not put HCL into an aluminium container for example. Also and actually more important, I have to 'pour' the melted sulphur
and potassium into hot water, hence the spoon idea because the test tube lets it cool down too much as it pours. But yes, I know I will experiment
more on this. By the way, I could mix the Liver of sulphur in an empty peanut butter container really. I think that the spoon, being metal, is so
hot that it cools too rapidly on contact even with the hot water that it affects the melted sulphur and KOH mix. I am just going to try some different
things out and see what happens.
Oh all those red lines under all my words, it happens often on other posts, you Americans really have rebelled against Our Saxon English spelling eh?
Tch.
Kind regards.
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CHRIS25
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| Quote: Originally posted by AndersHoveland | | Sodium sulfite, Na2SO3, solutions can also "dissolve" sulfur, but of course this is a chemical reaction producing thiosulfate. But the sulfur can be
precipitated out again by acidifying the solution. |
Hi Sorry for not replying sooner, but I was doing some reading on the above. Could not find much but this is interesting. I have my Sodium
Thiosulphate right? Something I wanted earlier. I dissolve Sodium metabisulphite, which automatically gives Sodium bisulphite. I add Sulphur and
get Sodium Bisulphate?
Na2So3 + H2O + S (Heat up) = Na2S2o3 Is this correct please?
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barley81
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If I wanted to make sodium thiosulfate, I would neutralize the sodium bisulfite solution with sodium hydroxide to make sodium sulfite. Then I'd boil
with sulfur. The ratio is 1 mole of sodium metabisulphite to two moles of sodium hydroxide.
Unfortunately I don't think you can use cheaper sodium carbonate because sodium sulfite is more basic than sodium bicarbonate and there will be some
sodium bisulfite, sulfite, and bicarbonate left in equilibrium (since pKa of carbonic acid is lower than pKa of bisulfite ion). However, I'm not sure
what happens when you boil sulfur in this mixture. Perhaps CO2 gets boiled away and you do get sodium thiosulfate?
Bisulfate isn't formed. To make bisulfate you can oxidize bisulfite. For example, you could add hydrogen peroxide to a solution of sodium bisulfite
(or sodium metabisulfite).
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CHRIS25
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Thanks Barley. Plenty to get on with then.
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watson.fawkes
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| Quote: Originally posted by CHRIS25 | | Anyway to answer your questions: Sulphur melts at 115 centigrade. Firing temp of clone 06 clay was not consistent, so I averaged everything to two
results: Between 1798 and 1855 F and 1828 to 2088F, and finally Borosilicate glass softens at 820 F. [...] my concerns come with reactivity of
compounds and liquids with their holding materials |
So here's a free one: both ceramics and glass are
chemically compatible with your reaction. And you've now understand that you should be able to use either material for your reaction vessel. If you
can find flower pots without drain holes, you should be able run this reaction in a campfire.
Now the pouring hot reaction mixture into water---what's that about? All you do is fires these two reagents together. Then you let it cool off. Only
then do you hydrolyze by putting the material into solution. Then you use the solution for patina work (or whatever else).
So start with about a 2 g batch in a test tube. Calculate, say, a 25% molar excess of sulfur assuming that the potassium reacts entirely to
K2S. This requires some simple stoichiometric calculations. I really doubt your original ratio (a teaspoon of sulfur to a flake of KOH) is
anywhere near the right ratio. You want to start small so that you can test that what you're doing is getting you where you want to go.
Oh, and keep your lab notebook current. You did write down those temperatures, right?
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CHRIS25
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Yes I appreciate your help in all this. Although I am aware of that plastic glass and ceramic are for the most part inert, I did not want to get
caught out trying to melt some stuff in ceramic - I have a few compatibility lists gleaned from the internet, unfortunately while helpful they are
geared towards their own Factory products so some of the more common materials are naturally not mentioned.
Have a nice day.
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CHRIS25
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Hi watson fawkes: said "Now the pouring hot reaction mixture into water---what's that about? All you do is fires these two reagents together. Then
you let it cool off. "
Well my suspicions were indeed confirmed. It does not work in a test tube. Once you add the KOH and melt it simply adheres to the sides and bottom
of the tube, basically you can't pour it either hot or cold. So back to the Spoon and just sacrifice some un-dissolved sulphur by adding more that I
need at the beginning.
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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watson.fawkes
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| Quote: Originally posted by CHRIS25 | | It does not work in a test tube. Once you add the KOH and melt it simply adheres to the sides and bottom of the tube, basically you can't pour it
either hot or cold. |
Liver of sulfur is a solid. Are you expecting a liquid reaction product?
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CHRIS25
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No, you can buy liver of sulphur as a solid or as a liquid. But all it is, as I am sure you know, is a loose combination of polysulphides,
bisulphides and sulphides etc. But themain ingredient seems tyo be potassium polysulphide, which strictly speaking is a substitute, however it does
the job exactly the same. Now when you mix the KOH and the S and melt they immediately dissolve into water and you have essentially your LOS. The
solid that you buy you also mix with water but since their solid immediatley dissolves one can only assume that there is a 'another' ingredient which
promulgates dissolution without any sulphur being precipitated.
**I probably should add that most of my mixture does dissolve, it is not a huge problem, just would be nice to quantify and keep consistent weights
and measures which Ican not do accurately if some sulphur keeps precipitating.
[Edited on 25-4-2012 by CHRIS25]
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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watson.fawkes
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| Quote: Originally posted by CHRIS25 | | **I probably should add that most of my mixture does dissolve, it is not a huge problem, just would be nice to quantify and keep consistent weights
and measures which Ican not do accurately if some sulphur keeps precipitating. |
Like I said, I'll bet you've
got a large molar excess of sulfur, too much to react even into polysufides. Since this is a quantitative question, please tell me what masses you're
using at the test tube scale, and how you came to use those values. These questions have numerical answers.
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CHRIS25
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I can not give you numerical answers because:
1. I do not have scales that measure accurately, 1 gram is quite hard to ascertain. They are household scales, pretty accurate if you are using 10
and above grams, since I have performed many successful reactions in this weight region.
2. My sulphur is a one third slightly heaped standard teaspoon and the KOH is a reasonably rounded 1 cm diameter.
Now I know you are going to collapse in despair at this un-scientific manner. But without those chemistry scales I can do no better. Look at this
way, many many experiments and discoveries were made even before the middle ages, and well, at such small minute quantities that would have been done
with the eye and chalked level indicators. seriously though I saw this demonstration done on You tube by a metal worker in silver. He did not have
any precipitates, but then he also did not give any precise temperatures of the water and kept using the phrase "approximately" and "about".
For the rest you can be pretty much comforted by my attention to empirical observations and analysis.
Kind regards, Chris
‘Calcination… is such a Separation of Bodies by Fire, as makes ‘em easily reducible into Powder; and for that reason ‘tis call’d by some
Chymical Pulverization.’ (John Friend, Chymical Lectures London, 1712)
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. (William Penn 1644-1718)
The very nature of Random, Chance development precludes the existence of Order - strange that our organic and inorganic world is so well defined by
precision and law. (me)
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watson.fawkes
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| Quote: Originally posted by CHRIS25 | | Now I know you are going to collapse in despair at this un-scientific manner. But without those chemistry scales I can do no better.
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No, I'm going to insist that you acquire the most basic scientific equipment if you want scientific help.
There are very inexpensive electronic scales available (they tend to be made in China). They're good to a tenth of a gram or so. One of those would do
you fine for test-tube scale experiments. So buy one.
In the US you can get one easily for less than $20. I just checked eBay for Ireland, and even with "items only in Ireland" turned on, I found a couple
dozen quickly. Plenty were less than 15 euros after shipping. I'm sure eBay isn't the only source for these. Useful search terms include "jewelry
scale" and "digital scale".
While you are waiting for your scale to arrive, here's more homework: do the stoichiometric calculations. Pick an equation to do the estimate with;
I'd suggest one with K2S as a product. (Hint: Wikipedia) Then figure out what mass ratio you're targeting.
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