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hodges
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Substance that Melts at Room Temperature?
I am interested in obtaining (preferably making) a substance that melts at close to room temperature (around 25C). Any ideas?
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JustMe
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The most obvious example for near room temperature (a little bit warmer) is the metal Gallium.
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neutrino
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You might want to try field's metal. It melts in hot water and is non-toxic. Here's a page talking about some metals you could make at home. A good metal that comes to mind is cesium (mp = 28.5*C), although this
isn't something you could make at home.
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BromicAcid
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95% Gallium 5% Indium = Mp 25 C
As for others, DMSO has a melting point of 18.45 C there are many others, i.e., high chain alcohols, and such that come to mind but don't give a
specific name in my mental rolodex. I will post anything else I can come up with later, you prefer organic or inorganic? Some ionic liquids come to
mind as having solidification points around room temperature.
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Polverone
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DMSO melts around 18 C. Tert-butanol melts at 25 C, n-methyl acetamide at 28. The CRC Handbook of Chemistry and Physics has a table "Melting
point index of organic compounds" that can help you in your search.
This is where a database-version of the handbook would be useful: ask for all compounds with MP between 20 and 30 C then rank them by number of atoms
in formula in an attempt to get the simpler compounds first.
PGP Key and corresponding e-mail address
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neutrino
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| Quote: | | DMSO has a melting point of 18.45 C |
It may have a melting point at that temperature, but I doubt it would freeze all the way if you tried to freeze it. I'm assuming that it would be
similar to HAc. Although it melts at 16.6*C, how ofter do you see a solid block of the stuff?
edit: formatting
[Edited on 7-10-2004 by neutrino]
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BromicAcid
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I see a solid block of DMSO all the time, I keep it out in my shed so every time I go to use it, it's frozen and I have to take it inside. And
it's not that cold outside! Stupid DMSO freezing all the time.
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Tacho
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Phenol melts at 40,5ºC. Not exaxtly room temperature...
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Organikum
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Water mixed with sawdust melts EXTREMLY slow at roomtemperature, junks of a kilogram or more take MONTHS to melt down.
It takes of course also time to freeze the stuff though.
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neutrino
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Interesting. I guess the question remains, why doesn't GAA freeze completely?
edit: Finding the source that originally told me this, it seems I misread it. GAA would be a good substance for this temperature, as it does
freeze completely. Sorry about that.
[Edited on 7-10-2004 by neutrino]
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sylla
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What about SnCl4 ? I heard it was an ionic compound liquid at room temperature...
Am I Wrong ?
EDIT: fuck even if it is liquid it doesn't melt at room temp =)
[Edited on 7-10-2004 by sylla]
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garage chemist
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I've got a 12g lump of pure gallium (mp 29°C) and it takes a rather long time to melt in the hand. But once it is molten, it is really fun to
play with.
It is rather reactive towards air though and quickly forms an oxide layer which makes it very sticky, unlike mercury.
The chemical properties of Gallium are similar to those of aluminium, it also forms a compact, tough oxide layer on its surface. But when it is
molten, fresh metal is exposed to the air, and it oxidises again.
My gallium is very oxidised, it seems as it consists primarily of the oxide now.
Gallium is offered very often on ebay, but this is maximum purity gallium meant for making semiconductors, so it is very expensive.
Also, diphenylmethane melts at 26°C. This seems interesting, too.
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hodges
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Thanks. It looks like gallium would work, but it is quite expensive. I want enough to be able to keep an insulated container at close to room
temperature even as the external temperature varies. I figured heat of fusion of a substance with melting point near 25C would do this.
I don't have a problem with organic substances as long as they are not super-toxic (they don't need to be edible but shouldn't be
something where 1mg would kill you or something).
I wonder if DMSO, Tert-butanol, or n-methyl acetamide could be synthesized at home. Something tells me I could probably find a synthesis for DMSO at
Rhodium or a similar site. Can I make Tert-butanol from a spare can of butane I have? Just kidding.
It may turn out that the low-tech way of using an excess of water may do what I need the cheapest. Even far from its freezing point might work if I
used enough.
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neutrino
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Why not GAA? All you have to do is distill from vinegar, reflux with a suitable drying agent, and re-distill. Should be simpler than synthesizing
something .
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vulture
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Doesn't Na2SO4.10H20 loose it's crystal water at 32C? Not exactly room temperature, but close.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Mr. Wizard
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Try sodium thiosulfate, although it doesn't melt at room temperature, but it will crystalize at room temperature. It is photographic
'hypo'. It contains a large amount of water of crystallization; enough to dissolve it when heated. After cooling, the solution remains
liquid, until a 'seed' crystal or some other event triggers the crystallization. Sodium acetate also has this property, and is used in the
reusable hand warmers. Both are relatively non toxic and available.
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thunderfvck
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Methyl salicylate (aka oil of wintergreen) has a reported melting point of 19.4*C. ALthough when I've made it via the esterification of aspirin
with methanol I obtained a product that I assumed was of poor purity. It smelt delicious, but wasn't melting as I had hoped. I would imagine a
distillation of the solid would be necessary for reasonable purity.
This being the second time I had made the wintergreen oil, I noticed something quite strange. Over time, my large pile of methyl salicylate had begun
to lose its smell (very disappointing). I don't feel like starting a new thread on this, but I was wondering why this would be? It was lying on a
piece of paper, exposed to air. Perhaps it reacted with the air? I know that esters aren't the strongest of compounds and they tend to decompose,
especially in the precense of acid.
Anyway, I have this other stuff I had made initially and it's closed in a little RB flask. It's a beautiful red liquid that always has
crystals lingering around recrystillizing. Very nice!
Although probably not fit to your uses, I thought it'd be worth mentioning anyway...
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mick
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If you have got a 24 hour thermostasted water heater you might be able to work out how far away from it is the temperature you want. It should be
fairly constant.
If you want to keep some thing at a fairly constant cool temperature dig a hole out of the sun, at a guess about 3-4 foot deep, and cover the stuff
with insulating material.
mick
Sorry, about the hole, also you want make sure it is dry so it should not be any where that could fill up with rain and get wet.
edit mick
[Edited on 8-10-2004 by mick]
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neutrino
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thunder: What is this liquid you speak of? A solution of some sort? About the methyl salicilate, I would guess that it sublimed, leaving impurities
behind. Or, there's carbonic acid from the air, although I thought hydrolyis only occured with excess water.
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thunderfvck
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Sorry, the liquid is methyl salicylate from a smaller batch I had made and placed in a little RB flask that I had covered. It was initially a powder I
believe but it turned into a liquid in the flask and now it has crystals of MS growing in it.
As for the weirdened stuff, allow me to explain a bit more now that I'm out of school. I made MS with aspirin in methanol with some H2SO4 and
reflux. Then I filtered it and had been meaning to distill it but I never got around to doing that. So I just took the filtered MS and put it on a
piece of paper. It smelt wonderfully of MS then. Then a few months pass, while the MS lies on a piece of paper in my dingy basement, and I take
another wiff and find that it has no scent at all. So it can't be the same chemical anymore because MS has a distinctive smell! So, this is it. I
was just wondering what could have happened. There's was still possibly acid in the MS when it was sitting, and moisture in the air...So
hydrolyzed then?...Yeah! Okay, sorry for going off topic.
[Edited on 9-10-2004 by thunderfvck]
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HNO3
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Ummm, doesn't a smell come from a substance diffusing? And since its diffusing, eventually there will be none left?
\"In the beginning, God...\" Wait a minute, God doesn\'t exist!!!!!!!!!! \"OK, in the beginning, ummm, hydrogen...\" Wait a minute, what about the
laws of thermodynamics? \"OK, in the beginning, ummm.....UMMMMM, what\'s left to choose from?
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budullewraagh
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wood's metal works as well
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neutrino
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CH<sub>3</sub>COOH (GAA) = 16*C
CH<sub>3</sub>(CH<sub>2</sub> <sub>10</sub>COOH
(lauric acid) = 45*C
There are plenty of molecules between these two which should melt around room temperature. You might have luck extracting them from various fats and
oils. Here is a thread about it.
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JohnWW
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The eutectic mixture of Na and K metals melts at room temperature or only just above, I believe.
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vulture
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And it is also spontaneously flammable in air...
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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