Sciencemadness Discussion Board - Substance that Melts at Room Temperature?

Substance that Melts at Room Temperature?

hodges - 6-10-2004 at 15:15

I am interested in obtaining (preferably making) a substance that melts at close to room temperature (around 25C). Any ideas?

JustMe - 6-10-2004 at 16:01

The most obvious example for near room temperature (a little bit warmer) is the metal Gallium.

neutrino - 6-10-2004 at 16:22

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.

BromicAcid - 6-10-2004 at 16:36

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.

Polverone - 6-10-2004 at 16:43

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.

neutrino - 6-10-2004 at 19:22

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]

BromicAcid - 6-10-2004 at 19:38

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.

Tacho - 7-10-2004 at 03:08

Phenol melts at 40,5ºC. Not exaxtly room temperature...

Organikum - 7-10-2004 at 04:54

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.

neutrino - 7-10-2004 at 13:50

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]

sylla - 7-10-2004 at 14:16

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]

garage chemist - 7-10-2004 at 14:23

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.

hodges - 7-10-2004 at 15:00

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.

neutrino - 7-10-2004 at 15:17

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

vulture - 8-10-2004 at 00:56

Doesn't Na2SO4.10H20 loose it's crystal water at 32C? Not exactly room temperature, but close.

Mr. Wizard - 8-10-2004 at 06:05

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.

thunderfvck - 8-10-2004 at 06:13

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...

mick - 8-10-2004 at 09:11

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]

neutrino - 8-10-2004 at 18:30

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.

thunderfvck - 8-10-2004 at 23:14

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]

HNO3 - 27-11-2004 at 17:04

Ummm, doesn't a smell come from a substance diffusing? And since its diffusing, eventually there will be none left?

budullewraagh - 27-11-2004 at 19:46

wood's metal works as well

neutrino - 27-11-2004 at 20:22

CH3COOH (GAA) = 16*C
CH3(CH2

10COOH (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.

JohnWW - 28-11-2004 at 01:30

The eutectic mixture of Na and K metals melts at room temperature or only just above, I believe.

vulture - 28-11-2004 at 01:50

And it is also spontaneously flammable in air...

unionised - 28-11-2004 at 05:34

"The eutectic mixture of Na and K metals melts at room temperature or only just above, I believe."

Must be chilly in your place, that stuff melts 12 degrees below freezing.

Glycerine

MadHatter - 28-11-2004 at 21:08

Glycerin will freeze on a block of ice. It stays solid below 20 C (68 F). Just an idea.

neutrino - 29-11-2004 at 14:27

Theoretically, it will. The only problem is that glycerin is one of those things that is very hard to crystalize.

If_6_was_9 - 3-12-2004 at 17:44

Coconut oil

Freezing/Melting Observations

hodges - 13-7-2006 at 15:54

I recently obtained some new chemicals, including DMSO and 99% acetic acid. I put a few ml of each in two test tubes and put them in the refrigerator.

The DMSO froze quickly. The acetic acid remained a liquid. So I put the acetic acid in the freezer (-20C). It still did not freeze. I stirred it with a plastic dropper and it froze.

I watched the behavior of these solids as I warmed the test tubes with my hand. The acetic acid melted rapidly, starting to form liquid before I even put my hand on the test tube. It was all melted in a minute. The DMSO, on the other hand, stayed solid for a long time, and felt cold to my hand the whole time. I have not looked up the heats of fusion for these two substances but I would guess based on my tests that DMSO has a far higher heat of fusion than acetic acid. DMSO might prove practical for storing heat/cold. I doubt acetic acid would be.

Hodges

12AX7 - 13-7-2006 at 19:09

Hmm, so supersaturated solutions aren't restricted to metal acetates, eh?

Tim

DeAdFX - 13-7-2006 at 19:56

Tert Butyl Alcohol The stuff is sometimes a frozen block or a clear liquid at room temp

ethan_c - 14-7-2006 at 15:50

this is an old, old thread, but…

cesium, anyone?

JohnWW - 14-7-2006 at 18:28

Caesium is too dangerous to handle - must not be exposed to any gases or liquids other than argon and aliphatic hydrocarbons. How about gallium, instead? (M.pt. 29ºC), or, for a lower melting point, eutectic mixtures of it with indium, bismuth, tin. Mixing it with mercury would also work, but there would be the toxicity problem.

unionised - 15-7-2006 at 01:00

Caesium and gallium were 2 of the early sugestions Did you read the thread before posting those replies?

ethan_c - 15-7-2006 at 06:03

Quote:

Originally posted by unionised
Caesium and gallium were 2 of the early sugestions Did you read the thread before posting those replies?

Woop. I did, but I didn't see neutrino's single-sentence mention of Cs.

I just like the idea more than anything. I really want to spend a paycheck on a big ol' ampoule as a present to myself.

Fleaker - 15-7-2006 at 13:46

I'm pretty sure dodecane melts at about 22.4C always solid whenever I look at the bottle in the laboratory.

unionised - 16-7-2006 at 01:08

Since the literature value for the melting point of dodecane is about 12 degrees below freezing I think you need a better heater in the lab.
Are you sure you don't mean docosane (bpt 224 @15mmHg)

Fleaker - 21-7-2006 at 10:52

Gah, not dodecane, I meant *heptadecane* (at least I was right about the decane part

, but still 5 carbons off).

IrC - 21-7-2006 at 13:35

I made a mix of tin, bismuth, gallium, and various and sundry other metals which melts just sitting on my table.

The_Davster - 21-7-2006 at 13:36

In what ratio?

IrC - 21-7-2006 at 14:47

Who knows, just playing around adding this and that. I have lots of the metals. Oh yeah, I forgot, I put Indium in there also. Don't ask how much, it was not a scientific experiment, just boredom.

If it did something super futuristic I am sure I could do more controlled mixing and recreate it. Was trying to make ways to mirror my super thin carbon to float on top my magnets and make a cool sensor for something or other.

I am thinking it was around 45 percent Bismuth, 10% Tin, 30% Gallium, 15% Indium. It is also in the high 80's to low 90's in here (I get lung infections every summer around July if I run too much AC all the time, so I shut it off every so often), and you can tell it is melting while it is not a liquid completely.

[Edited on 22-7-2006 by IrC]

multiple liquid phases, anyone?

-jeffB - 19-12-2007 at 09:12

Quote:

Originally posted by JohnWW
Caesium is too dangerous to handle - must not be exposed to any gases or liquids other than argon and aliphatic hydrocarbons. How about gallium, instead? (M.pt. 29ºC), or, for a lower melting point, eutectic mixtures of it with indium, bismuth, tin. Mixing it with mercury would also work, but there would be the toxicity problem.

A search on Google for gallium mercury yields this as the first link:

http://www.springerlink.com/index/U4614M3617W0G7Q3.pdf

You probably need institutional access or a subscription to get at the paper, but the bottom line is that mercury is only slightly soluble in gallium (or vice-versa) -- less than 1%, until you reach a critical point at 203.5ºC.

I looked into this some time ago when I was trying to figure out the maximum number of mutually immiscible liquids you could put in a bottle at something approaching STP. I got as far as mercury, gallium, silicone oil, fluorocarbon, water, hydrocarbon -- six phases, mutually immiscible, although I'm not completely convinced I could keep the silicone oil from fraternizing with both the hydrocarbon and the fluorocarbon. Can anyone suggest a seventh phase? For that matter, can anyone suggest a transparent container substance that is inert to the whole list and isn't wetted by gallium? It's not such a fun demo if the gallium sticks to the bottle, turning it into a mirror and hiding everything else...

Xenoid - 19-12-2007 at 10:13

This company (Indium Corporation)

http://www.indium.com/products/fusiblealloys.php

makes a range of gallium/indium alloys with MPs ranging from about 7 oC. up to 30 oC.

They are marketed as mercury substitutes (for physical processes). I haven't enquired about the prices.....

dann2 - 19-12-2007 at 11:12

Hello,

Try a search for Woods metal for low melting point compositions.

They will be above room temp though

Dann2

unionised - 19-12-2007 at 11:36

-jeffB
If you saturate the water with salt then you can add acetonitrile as another phase.

-jeffB - 19-12-2007 at 12:59

Quote:

Originally posted by unionised
-jeffB
If you saturate the water with salt then you can add acetonitrile as another phase.

Interesting! But I fear the salt water would attack the gallium, especially in galvanic contact with the mercury. Rats.

That might be a good phase to replace the gallium outright, though -- the gallium is sticky, and the interface between the gallium and mercury would probably be hard to see.

Is acetonitrile really immiscible with hydrocarbons/fluorocarbons/silicones? I'm getting seriously tempted to actually try this...