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Author: Subject: I want to hear your favorite chemistry demonstrations
Vomaturge
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[*] posted on 2-2-2018 at 01:46


Potassium permanganate and glycerin, water boiling at room temperature and reduced pressure, hydrogen balloons filled using aluminum and sodium hydroxide.
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Morgan
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[*] posted on 28-11-2019 at 15:55


Here's an apropos jam jar jet demonstration for the chemistry crowd or stress testing the borosilicate glass.

Erlenmeyer Flask Jam Jar Jet Snorkeler
https://www.youtube.com/watch?v=mDrdUy-LWHY

[Edited on 28-11-2019 by Morgan]
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Morgan
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[*] posted on 2-2-2021 at 13:12
Musical Flames and other excerpts


From the physicist John Tyndall's book "Sound" in the 1800's.
A long tube in the verticle ...

Fig. 114. Fig. 114.A still more striking effect is obtained with this larger tube, a b, Fig. 114, 15 feet long and 4 inches wide, which was made for a totally different purpose. It is supported by a steady stand, s s′, and into it is lifted the tall burner, shown enlarged at B. You hear the incipient flutter: you now hear the more powerful sound. As the flame is lifted higher the action becomes more violent, until finally a storm of music issues from the tube. And now all has suddenly ceased; the reaction of its own pulses upon the flame has beaten it into extinction. I relight the flame and make it very small. When raised within the tube, the flame again sings, but it is one of the harmonics of the tube that you now hear. On turning the gas fully on, the note ceases—all is silent for a moment; but the storm is brewing, and soon it bursts forth, as at first in a kind of hurricane of sound. By lowering the flame the fundamental note is abolished, and now you hear the first harmonic of the tube. Making the flame still smaller, the first harmonic disappears, and the second is heard. Your ears being disciplined to the apprehension of these sounds, I turn the gas once more fully on. Mingling with the deepest note you notice the harmonics, as if struggling to be heard amid the general uproar of the flame. With a large Bunsen’s rose burner, the sound of this tube becomes powerful enough to shake the floor and seats, and the large audience that occupies the seats of this room, while the extinction of the flame, by the reaction of the Fig. 115. Fig. 115.sonorous pulses, announces itself by an explosion almost as loud as a pistol-shot. It must occur to you that a chimney is a tube of this kind upon a large scale, and that the roar of a flame in a chimney is simply a rough attempt at music.

The action reminds one of the story of the Swiss muleteers, who are said to tie up their bells at certain places lest the tinkle should bring an avalanche down. The snow must be very delicately poised before this could occur. It probably never did occur, but our flame illustrates the principle. We bring it to the verge of falling, and the sonorous pulses precipitate what was already imminent. This is the simple philosophy of all these sensitive flames.

A flame of astonishing sensitiveness now burns before you. It issues from the single orifice of a steatite burner, and reaches a height of 24 inches. The slightest tap on a distant anvil reduces its height to 7 inches. When a bunch of keys is shaken the flame is violently agitated, and emits a loud roar. The dropping of a sixpence into a hand already containing coin, at a distance of 20 yards, knocks the flame down. It is not possible to walk across the floor without agitating the flame. The creaking of boots sets it in violent commotion. The crumpling, or tearing of paper, or the rustle of a silk dress, does the same. It is startled by the patter of a rain-drop. I hold a watch near the flame: nobody hears its ticks; but you all see their effect upon the flame. At every tick it falls and roars. The winding up of the watch also produces tumult. The twitter of a distant sparrow shakes the flame; the note of a cricket would do the same. A chirrup from a distance of 30 yards causes it to fall and roar.

At a distance of 30 yards, for example, the chirrup of a house-sparrow would be competent to throw the flame into commotion.

Curved roofs and ceilings and bellying sails act as mirrors upon sound. In our old laboratory, for example, the singing of a kettle seemed, in certain positions, to come, not from the fire on which it was placed, but from the ceiling. Inconvenient secrets have been thus revealed, an instance of which has been cited by Sir John Herschel.16 In one of the cathedrals in Sicily the confessional was so placed that the whispers of the penitents were reflected by the curved roof, and brought to a focus at a distant part of the edifice. The focus was discovered by accident, and for some time the person who discovered it took pleasure in hearing, and in bringing his friends to hear, utterances intended for the priest alone. One day, it is said, his own wife occupied the penitential stool, and both he and his friends were thus made acquainted with secrets which were the reverse of amusing to one of the party.

The celebrated French philosopher, Biot, observed the transmission of sound through the empty water-pipes of Paris, and found that he could hold a conversation in a low voice through an iron tube 3,120 feet in length. The lowest possible whisper, indeed, could be heard at this distance, while the firing of a pistol into one end of the tube quenched a lighted candle at the other.


[Edited on 2-2-2021 by Morgan]
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Morgan
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[*] posted on 24-2-2021 at 11:29


Quote: Originally posted by Morgan  
Yesterday I was toying with a pale yellow mushroom that forms a sack with a goodly amount of spores inside, the kind that billow a lot of smokey spores when popped. The mushroom wasn't some perfectly round kind you sometimes see but an odd very light weight, pale yellow and brown, elongated bumpy membrane somewhat egg-shaped and it didn't seem to have an pronounced attachment point where it rooted to the ground. So the thought was to see how the spores might burn if held next to a lit Bic lighter.
Surprisingly, when the partially split sac of spores was compressed near a flame the fireball the burning spores made was quite perky, reminiscent of lycopodium powder. So if you had a large amount of these which were collected for their spores, perhaps they'd be a comparable/alternative "dragon's breath" source, slightly quirky or road less traveled.

I wonder if you had someone standing by with a lit propane torch if this puffball spore cloud would burst into flames?
https://www.youtube.com/watch?v=5TeFsg9e-ks

Update
Researching Astraeus hygrometricus recently perhaps it's spores would work as well as lycopodium for some effects if you could gather enough of them. I bought a couple of 3 ounce bottles of lycopodium spores a few years ago, which is fairly bulky like powdered charcoal but not all that inexpensive.
https://youtu.be/rXGy2KjefDw


[Edited on 24-2-2021 by Morgan]
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[*] posted on 24-2-2021 at 13:35


Burning various compounds in stream of oxygen is nice experiment, I tried this few years ago with some chemicals: sulfur, titanum, aluminium, magnesium, iron, charcoal, wood and sugar:

https://youtu.be/lYtUHB1LtfY

Other amazing experiment that I tried is spectacular autoignition of finely powdered zinc with ammonium nitrate with some ammonium chloride. After add a drop of water it "explodes" with greenish- blue flame:

https://youtu.be/uYjyH1ZQXdI

[Edited on 24-2-2021 by Piroz]
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Morgan
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[*] posted on 9-4-2021 at 07:29


Here's a clever variation on a theme. Sometimes you see a sleeve over the tube to modulate the pitch like a trombone, but this was amusing.
The world first blowless flute - I play a melody on my thermoacoustic engine
https://youtu.be/Qqk36IZqIgY

Another more basic variant
Singing Test Tubes
https://youtu.be/iN2P6KU9bEg

I was wondering if a battery driven tiny piezo speaker/tone generator placed inside a tube with holes at the end could be played as musical instrument in a band for novelty. It would be funny to see a flute-like instrument but without the need to have it near your mouth or constricted by having a flame tied to it, walking around while you played it.

[Edited on 9-4-2021 by Morgan]
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ChemichaelRXN
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[*] posted on 9-4-2021 at 10:24


Oil and vinegar

No just kidding...

I liked the video by ChemicalForce where he mixed carbon disulfide and Potassium superoxide. It explodes like it was a high explosive almost. (I dont deal with explosives...laws etc. I just watch youtube)




We are the same perception looking out, from the same elements around the universe.

We are everything to be anything to begin with.

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Morgan
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[*] posted on 17-4-2021 at 07:48


I saw this repurposed device that might be handy for some demonstrations. There're some for less than $20.00 on ebay.

Mini Handheld Tesla Coil(Oudin Coil
https://youtu.be/x0QmomYHt_I

Say for things like this or whatever creative use you might think of.
Volta's Pistole,Volta's Pistol
https://youtu.be/WZerYRGU33c

Methanol Cannon
https://youtu.be/Wn5wr9ZAq3s
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Morgan
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[*] posted on 17-10-2021 at 11:13


Quote: Originally posted by Morgan  
Yesterday I was toying with a pale yellow mushroom that forms a sack with a goodly amount of spores inside, the kind that billow a lot of smokey spores when popped. The mushroom wasn't some perfectly round kind you sometimes see but an odd very light weight, pale yellow and brown, elongated bumpy membrane somewhat egg-shaped and it didn't seem to have an pronounced attachment point where it rooted to the ground. So the thought was to see how the spores might burn if held next to a lit Bic lighter.
Surprisingly, when the partially split sac of spores was compressed near a flame the fireball the burning spores made was quite perky, reminiscent of lycopodium powder. So if you had a large amount of these which were collected for their spores, perhaps they'd be a comparable/alternative "dragon's breath" source, slightly quirky or road less traveled.

I wonder if you had someone standing by with a lit propane torch if this puffball spore cloud would burst into flames?
https://www.youtube.com/watch?v=5TeFsg9e-ks

After looking over some photos I think it's possible that the mushroom I found was an earthstar as there were a few dozen banana peel looking things in my lawn that came after some rains. If you look at the 3rd photo that's sort of what my flammable spore ball looked like but more of a potato shape without the perfect round shape with a pointy top.
http://www.realmonstrosities.com/2013/06/earthstar.html
Or it could have been something like this poisonous earthball.
http://www.wildutah.us/html/plants_scenery/h_mushroom_earthb...


[Edited on 31-1-2017 by Morgan]


Having thought puffball spores might make a good substitute for a lycopodium dragon"s breath demo it seems if you worked with the spores a lot or were more allergic than most people for some reason, maybe there could be a slight risk to your health. In the above, there's a guy who runs over a giant puffball with his mower creating a big cloud of spores.

"In one particularly unfortunate case, a group of eight apparently sober teenagers decided it would be a good idea to inhale the spores squeezed from some puffballs they had acquired. After a couple of days, they started to cough, had trouble breathing, ran a fever, and felt generally crappy. Things got so bad that five of the teens were hospitalized, two of them needing to be intubated to help them breathe. Their inflamed lungs were treated with corticosteroids and they all eventually recovered from their illness."

"Lycoperdonosis has also been seen in people who snorted puffball spores as a folk remedy for a nosebleed. Both puffballs and earthstars have killed or seriously injured dogs who disturbed them and inhaled their spores as they ran about or dug holes."
http://www.rosincerate.com/2016/03/how-bacteria-and-fungi-ca...

It seems even lycopodium can be hazardous in some cases.
https://www.sciencedirect.com/topics/pharmacology-toxicology...


[Edited on 18-10-2021 by Morgan]
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[*] posted on 17-10-2021 at 14:53


This demonstration is more material science than chemistry, but you take a length of music wire (high carbon steel) and stretch it between two ring stands. Then you pass an electric current through the wire causing it to heat up. As the wire heats up it starts to sag from thermal expansion, but when the wire hits the austenite transition temperature the wire lifts slightly as the body-centered cubic ferrite in the steel is converted to the more densely packed face-centered cubic austenite causing the wire to contract. The wire then starts to sag again as the temperature is increased. The effect is more pronounced in reverse when the wire contracts as it cools, then sags at the phase transition temperature, and contracts as it cools further.
https://youtu.be/W6Pa4n4Abyw
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[*] posted on 20-10-2021 at 11:10


maybe not a demonstration but If you mix some glycerol with potassium chlorate and ignite, it burns for a bit and when hot enough it goes うじゅうぅぅ〜〜ん! Big flame upwards - I think it's pretty cool



Hi, please read about exif data.
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