Sciencemadness Discussion Board - Chem Demo: Powders Becoming Liquids

Chem Demo: Powders Becoming Liquids

careysub - 5-9-2015 at 09:15

Years ago I read in an old chemistry manual (early 20th century) about a chemical demonstration that pointed out while mixing liquids and getting solids is commonplace the reverse is not, and had a demo in which two finely powdered substances were vigorously shaken together in a test tube, which became a liquid.

Can anyone propose what this might have been, or a similar demonstration reaction?

aga - 5-9-2015 at 11:32

Zinc Chloride and Choline Chloride - maybe.

I know next to nothing at all, so don't quote me.

Edit :

That makes a deep eutectic, yet it can hardly be called a liquid at RT.

Using my advanced google SuperPowers i typed in 'Chemistry demonstration two solids make liquid' then i pressed Enter and found this :-

http://www.nuffieldfoundation.org/practical-chemistry/endoth...

"Solid hydrated barium hydroxide is mixed with solid ammonium chloride ... produce a liquid" for the hard of Clicking.

[Edited on 5-9-2015 by aga]

careysub - 5-9-2015 at 12:39

Your Google-fu is powerful!

I tried a number of search combinations and waded through scores of potential results without finding that.

There must be others though - I am pretty sure copious ammonia and sub-zero temperatures were not featured in the ancient chem text of yore.

[Edited on 5-9-2015 by careysub]

Texium - 5-9-2015 at 12:47

Choline chloride or choline bitartrate (easier to find OTC) and urea will make a deep eutectic solvent that is a bit viscous but still definitely liquid at room temperature. Unfortunately, it doesn't happen instantaneously. For me it took an hour or so for the mixture to become a thick, syrupy consistency after a good amount of mixing and shaking, and a few more for it to completely liquefy. I used the bitartrate though. The chloride probably works better, and it's easily made from the bitartrate by reaction with potassium chloride, as potassium bitartrate has very low solubility. (and then if you have some antimony trioxide handy, you can try this procedure in which two insoluble compounds will react under reflux to form a soluble double salt with a neat crystal structure).

[Edited on 9-5-2015 by zts16]

aga - 5-9-2015 at 12:53

Unfortunately i tried too hard to find more "two solid chem makes liquid" references, which exhausted my Google-Chi.

Found far too many references to "Hot Chick" which i must now read repeatedly.

No Alien Lizard can forego a bag full of Hot Chicks when hungry.

aga - 5-9-2015 at 13:01

Do people generally have antimony trioxide handy ?

Texium - 5-9-2015 at 13:50

Quote: Originally posted by aga

Do people generally have antimony trioxide handy ?

Probably not, but it's fairly inexpensive from the pottery store, and there's not a ton of stuff you can do with it, so if you do happen to have some laying around, it's quite likely that you'd be happy to find something interesting to do with it.

careysub - 5-9-2015 at 16:23

Does the antimony trioxide have to do with the "becoming liquids" bit, or the "hot chicks"?

Either way perhaps I should get some? :-)

violet sin - 5-9-2015 at 19:19

Just found this.. first try
http://www.answers.com/Q/Can_two_solids_combine_to_make_a_li...
Menthol and camphor.

Apparently this is a common search. Typed in "two solids" and Google suggested the rest for me. The answer was second down.

Also sodium + potassium

[Edited on 6-9-2015 by violet sin]

careysub - 5-9-2015 at 21:28

You have exposed Aga and me as the Google charlatans that we are, to have failed in this task!

And I think this is very likely the demo from the olde book. It sounds right.

I will have to try this.

Here is a discussion of this experiment:
http://www.umanitoba.ca/outreach/crystal/Grade%209/Cluster%2...

It has this explanation:
"For camphor, however, its natural tendency is to sublimate, or go directly from a solid to a gas at room temperature, albeit rather slowly. When it is mixed with menthol, the new substance adulterates the camphor and the mixture forces it to go through the liquid state. In other words, adding a foreign substance will cause the substance to become impure and change its physical properties, or changes that do not change the composition of the substance."

And as a bonus for completing this experiment you have made your own supply of VapoRub concentrate! It would need diluting with an ointment basis (like petroleum jelly) about 20-fold, Vicks VapoRub contains 4.8% camphor and 2.6% menthol.

Aga's earlier example is kind of cooler (:-)) for a demo since it is a genuine chemical transformation. Even though the two accompanying phenomena of noxious gas evolution, and getting really, really cold kind of steal some of the 'melting' effect's thunder - and thus make it a less "pure" showcase of the phenomenon - you are getting three effects for the price of one.

[Edited on 6-9-2015 by careysub]

chornedsnorkack - 5-9-2015 at 22:29

Between eutectics of low-melting solids, which are liable to give rapid and nice reaction?
Na and K?
Lactic acid and lactic acid (both chiral forms melt at +53, racemate at +17)?
Others?

deltaH - 6-9-2015 at 01:44

ICE + NaOH

Morgan - 6-9-2015 at 07:33

Perhaps this isn't the best example of solids turning to liquid, but it's not bad. I've seen a more profound effect where the material is seemingly quite solid but turns to syrup upon being struck with a hammer. In the example I saw a solid rod of thixotropic material was tapped on the counter to illustrate how stiff it was before the transition.

https://www.youtube.com/watch?v=LgDQsYAcS3o

https://www.youtube.com/watch?v=UJsoCWqCsJ8#t=2m30s

aga - 6-9-2015 at 14:18

Quote: Originally posted by deltaH

ICE + NaOH

Erm, Ice powder ?

Is it anhydrous ?

j_sum1 - 6-9-2015 at 14:38

aga. I take it you don't get snow where you live.

aga - 6-9-2015 at 15:28

Snow got banned here when they discovered that Winter was caused by people storing snow on their rooves (presumably so they didn't have to go up into the mountains to get it).

I'd encourage everyone to stop storing snow on your roof and enjoy warmer weather all year round.

Here's the proof :-

First photo is of some Alaska people greedily shovelling snow onto their roof from a vast stockpile they already accumulated, which results in grey skies and crappy cold weather.

When people stop doing that, and leave the snow where it should be, it looks like this :-

Argentum - 6-9-2015 at 17:34

Ba(OH ) 2 + NH4Cl
Also a good demonstration of an endothermic reaction.

j_sum1 - 6-9-2015 at 18:54

Quote: Originally posted by Argentum

Ba(OH ) 2 + NH4Cl
Also a good demonstration of an endothermic reaction.

Yeah. For maximum effect, stir with a thermocouple. If you do it at a reasonable quantity on a block of wood with a little puddle of water tou can get the water to freeze and stick to the bottom of your beaker.

aga - 7-9-2015 at 00:01

Quote: Originally posted by Argentum

Ba(OH ) 2 + NH4Cl
Also a good demonstration of an endothermic reaction.

You may find that was in the first reply to the OP.

ave369 - 7-9-2015 at 02:10

Quote: Originally posted by aga

Snow got banned here when they discovered that Winter was caused by people storing snow on their rooves (presumably so they didn't have to go up into the mountains to get it).

What a load of bull. Everyone knows that winter is caused by the White Walkers.

deltaH - 7-9-2015 at 02:55

Quote: Originally posted by aga

Quote: Originally posted by Argentum

Ba(OH ) 2 + NH4Cl
Also a good demonstration of an endothermic reaction.

You may find that was in the first reply to the OP.

This is a lot like googling... the result you want is usually one of the first, the rest is all blah blah snow and salts... oh and someone's bound to be a nazi/hitler etc.

bismuthate - 7-9-2015 at 05:12

A solid acid + solid base (not to stong or it could be dangerous) might work like Mg(OH)2+2NaHSO4=Na2SO4+MgSO4+2H2O. Although I doubt it would work as well in theory.

MrHomeScientist - 8-9-2015 at 07:14

That quick clay demo is very cool, I'd never heard of that before. That would make a great hands-on demonstration for my outreach program. Anyone know if that stuff is for sale someplace? Geologist supply store? Anyone live in Norway that could dig some up?

The menthol and camphor demo is very cool too. I'd like to try that if I ever get menthol.

careysub - 8-9-2015 at 07:22

There is even a kit on eBay: "Ammonium Thiocyanate and Barium Hydroxide, 100g, Fast Freeze Reaction Experiment containing 100 g each of ammonium thiocyanate and barium hydroxide.

Any ammonium salt will do however. Ammonium chloride is cheap, Shakhashiri in his chem demo vol. 1 also uses ammonium nitrate.

unionised - 8-9-2015 at 11:25

Nobody mentioned indium and gallium?

Morgan - 8-9-2015 at 14:45

Quote: Originally posted by MrHomeScientist

That quick clay demo is very cool, I'd never heard of that before. That would make a great hands-on demonstration for my outreach program. Anyone know if that stuff is for sale someplace? Geologist supply store? Anyone live in Norway that could dig some up?

The menthol and camphor demo is very cool too. I'd like to try that if I ever get menthol.

The blasting of quick clay is sort of like the hammer effect I saw with a thixotropic material. It would be funny to mold certain shapes like large toy army men or zombie figurines or something like a vase and then whack them with a hammer.
https://www.youtube.com/watch?v=3q-qfNlEP4A#t=16m51s

mayko - 25-3-2016 at 12:16

I made a serenditipous observation while I was packaging my magic rocks gifts this Christmas I noticed that hydrated calcium chloride would appear to react with other salts it was packaged with, generating moisture. I've done a few experiments and have come up with some cool results. It's not the most striking of chemical demonstrations, but it uses chemicals which are likely to be on hand for even an austere DIY lab (unlike barium hydroxide or menthol/camphor, for example), and it has pedagogical relevence (to illustrate Le Chatlier's principle, or water of crystallization)

The general system relies on the reaction between two salts with high solubility and many waters of crystallization, to produce salts with low solubility and little if any water of crystallization, effectively releasing stored water. The most thoroughly explored subsystem involves hydrated calcium chloride with a hydrated metal sulfate:

$$CaCl_2.6H_2O + MSO_4.xH_2O -> CaSO_4.2H_2O + MCl_2 + (x+4) H2O$$

This seems to be catalyzed by trace moisture, provided in my case by slightly moist calcium chloride (no amount of acetone and/or pressing between blotters seems to dry out the salt I've recrystallized) or perhaps by ambient humidity (breathe on the reaction mixture to kickstart it?) Once the reactants dissolve slightly, the reaction is driven forward by the precipitation of insoluble calcium sulfate. The water released presumably accelerates the reaction by dissolving the reactants, and also further releasing water of crysallization in the dissolved salts.

Four examples of this subsystem were investigated by mixing the salts in a 1:1 molar ratio, adding to a test tube, sealing, and shaking to mix:

Code:


	M	x
I.	Cu	5
II.	Mg	6
III.	Fe	7
IV.	Na2	10

I. $$CaCl_2.6H_2O + CuSO_4.5H_2O -> CaSO_4.2H_2O + CuCl_2 + 9H_2O$$
This quickly became slushy, and I have a tube from one experiment in which this intermediate state left splashmarks on the sides of the tube. The mixture then seems to harden into a gummy-looking green plug of gypsum and copper chloride. Over a long time, the plug oozes fluid, but it would be hard to call the reaction a liquification.

CopperSulfate_CalciumChloride.jpg - 265kB

II. $$CaCl_2.6H_2O + MgSO_4.6H_2O -> CaSO_4.2H_2O + MgCl_2 + 10 H_2O$$
This also quickly liquifies and then resolidifies into a grainy paste.

MagnesiumSulfate_CalciumChloride.jpg - 271kB

III. $$CaCl_2.6H_2O + FeSO_4.7H_2O -> CaSO_4.2H_2O + FeCl_2 + 11 H_2O$$
This became “sweaty” looking and shrank into yellow, chalky-looking plug. It is rimmed with an orange color near the surface, possibly from Fe2+ reacting with oxygen in the test tube atmosphere. Not much in the way of free moisture is ever seen.

IV. This mixture fully liquifies into the consistency of Elmer's glue, remaining pourable. Over several weeks, transparent aqueous solution.

SodiumSulfate_CalciumChloride.jpg - 254kB

I also tried trisodium phosophate (Na3PO4 * 12H2O). Calcium phosphates are pretty insoluble, but it's not obvious the specific compound or mixture produced by this reaction ([url= https://en.wikipedia.org/wiki/Tricalcium_phosphate#Preparati... ]Wikipedia claims it's not tricalcium phosphate[/url] )and thus it's not obvious what the optimal stoichiometry is. I treated it as though it was producing tricalcium phosphate, and the intermediate stage was the most mobile and wet I saw, though it ultimately hardened to a paste. I also tried sodium tetraborate (Na2B4O7 * 10 H2O), but no reaction was observed at all.

Overall, IV. was the only mixture which I'd say reliably liquifies. However, I was able to get I.to form a lot of liquid water by layering the solids, rather than mixing them. I used a small enough tube that the layer of calcium sulfate that forms on the interface of the reactants tended to act like an arch which kept them out of contact, so the tube required frequent thumping to keep them in touch. Eventually it separated into distinct layers: moist copper sulfate, waterlogged copper sulfate, two distinct layers of calcium sulfate, an olive-green liquid layer, and what started out as undissolved calcium chloride but now looks like calcium sulfate sediment. I am trying this again right now in a larger tube, with the calcium chloride in the top layer, so that as it deliquesces the liquid flows downward and reacts (rather than simply pooling).

copper and calcium timelapse.jpg - 272kB

I've actually come to really like these reactions, even when they don't fully liquify. They're like mineralogical equivalent of a closed ecosystem display (http://www.instructables.com/id/How-to-Make-a-Closed-Aquatic...), which slowly develops over days or weeks. I'm putting together a time-lapse I filmed of reaction I. taking place; I'll post an animated gif of it soon!

I have a more rigorous, algebraic discussion of what's going on here that I'll post if people are interested enough for me to wade through the markup

mayko - 8-10-2019 at 16:25

This came from a longer handbook from University of Wisconsin cowritten by Don Showalter, the chem demo guy from World of Chemistry. It's surprisingly obscure and I could only get it piecemeal through interlibrary loan. But this was my core interest: a reaction in which ~20g each of iron (III) nitrate, mercury (II) chloride, and tin (II) chloride are layered in a large test tube. When the tube is shaken to mix, the reaction mixture liquifies into a thick yellow fluid which gets burped out of the test tube and down the side as nitrogen dioxide is evolved. When the reaction is over, the mixture solidifies into a tough yellow solid. The main reaction is apparently between the iron and tin salts, with the mercury chloride acting as a catalyst. This is given but ... I don't think it's balanced (products are short by 7H2O)
2[Fe(NO3)3*9H2O] +3[SnCl2*2H2O] -> 3SnO2 + 6NO2 + 5H2O + 2[FeCl3*6H2O]

I saw this once when I was very young and it made a big enough impression on me to track it down all this time later! I wonder if gallium or similar could be swapped out for the mercury for a "greener" demo?

Attachment: A solid State Reaction - old Belcher.pdf (582kB)
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