Black flames
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- andrewtretiakov
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Black flames
Be afraid be very afraid of black flames! This is a great demo for Halloween.
All about atomic emission and absorption spectroscopy as well as quantum theory.
When performing flame tests in the teaching lab, we ignite ethanol with different metal salts to observe the characteristic emission spectra. In this case, we added table salt or sodium chloride to produce the yellow-orange flames. This is caused by unstable excited electrons in sodium atoms that fall back to a more stable energy level or ground state emitting almost monochromatic yellow at 589 nm in the process. A low pressure sodium lamp placed right next to the flames also emits the same wavelength. The flames absorb that light & appear an eerie black.
Here's a short video:
https://youtube.com/shorts/8gZWSHxtHiw? ... mOP-NADL8d
#spookychemistry
All about atomic emission and absorption spectroscopy as well as quantum theory.
When performing flame tests in the teaching lab, we ignite ethanol with different metal salts to observe the characteristic emission spectra. In this case, we added table salt or sodium chloride to produce the yellow-orange flames. This is caused by unstable excited electrons in sodium atoms that fall back to a more stable energy level or ground state emitting almost monochromatic yellow at 589 nm in the process. A low pressure sodium lamp placed right next to the flames also emits the same wavelength. The flames absorb that light & appear an eerie black.
Here's a short video:
https://youtube.com/shorts/8gZWSHxtHiw? ... mOP-NADL8d
#spookychemistry
Re: Black flames
Very impressive pictures! Perfect for halloween - congratulations!
We have this experiment already documented here. But it seems that your version of burning alcohol with sodium chloride gives more impressive results.
We have this experiment already documented here. But it seems that your version of burning alcohol with sodium chloride gives more impressive results.
"Alles sollte so einfach wie möglich gemacht werden. Aber nicht einfacher." (A. Einstein 1871 - 1955)
"Wer nur Chemie versteht, versteht auch die nicht recht!" (G.C. Lichtenberg, 1742 - 1799)
"Die gefährlichste Weltanschauung ist die Weltanschauung der Leute, die die Welt nie gesehen haben." (Alexander v. Humboldt, 1769 - 1859)
"Wer nur Chemie versteht, versteht auch die nicht recht!" (G.C. Lichtenberg, 1742 - 1799)
"Die gefährlichste Weltanschauung ist die Weltanschauung der Leute, die die Welt nie gesehen haben." (Alexander v. Humboldt, 1769 - 1859)
Re: Black flames
I'll have to repeat the experiment one day. Phillips, for example, offers sodium vapor lamps. Nice work.
Cheers
Markus
Cheers
Markus
My youtube science channel
Laboratoriumdiscounter.nl Promotion Code: MARBSLAB2024 (10% auf alle Produkte).
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- andrewtretiakov
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Re: Black flames
Thank you! Yes, the flames look almost like a CGI effect. Difficult to believe until you see them.lemmi hat geschrieben: ↑Samstag 14. Oktober 2023, 22:12 Very impressive pictures! Perfect for halloween - congratulations!
We have this experiment already documented here. But it seems that your version of burning alcohol with sodium chloride gives more impressive results.
Cheers, A
- andrewtretiakov
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Re: Black flames
Yes, please do and let me know how it goes. Easy to prepare and very impressive in person.
Thank you Markus.
- mgritsch
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Re: Black flames
I agree, this is not new but by far the very best way to demonstrate it, have never seen it presented this cool!andrewtretiakov hat geschrieben: ↑Sonntag 15. Oktober 2023, 11:12 Thank you! Yes, the flames look almost like a CGI effect. Difficult to believe until you see them.
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Re: Black flames
This may work, but not tested yet:
If you have a strong bunsenburner or better a glassblowers torch you can heat glass in the flame to get a lot of sodium light. Put a shade between the torch and your alcohol fire with salt and a white screen behind both.
If you have a strong bunsenburner or better a glassblowers torch you can heat glass in the flame to get a lot of sodium light. Put a shade between the torch and your alcohol fire with salt and a white screen behind both.
Re: Black flames
SebastianV hat geschrieben: ↑Montag 16. Oktober 2023, 00:35Why cry?
Were can I buy a sodium lamp? What is the cheapest lamp?
viewtopic.php?f=33&t=6009&p=90158
bj68
Fuck the "REGULATION (EU) 2019/1148" of the European Parliament and of the Council...denn
Kunst und Wissenschaft, Forschung und Lehre sind frei. Art 5 Abs. 3 GG
Kunst und Wissenschaft, Forschung und Lehre sind frei. Art 5 Abs. 3 GG
Re: Black flames
https://www.grow-shop24.de/250w-ndl-nat ... 9wQAvD_BwESebastianV hat geschrieben: ↑Montag 16. Oktober 2023, 00:35 Were can I buy a sodium lamp? What is the cheapest lamp?
"Es lebe die Freiheit!" (Hans Scholl)
Re: Black flames
It looks not like a "Low pressure sodium" lamp....so can not use it....it has to be low pressurealiquis hat geschrieben: ↑Montag 16. Oktober 2023, 10:57 https://www.grow-shop24.de/250w-ndl-nat ... 9wQAvD_BwE
see "Since the high pressure sodium vapor lamp belongs in a rather low price range,..." https://www.growland.biz/Elektrox-Super ... -400W-600W
Edit: Search for "Philips SOX"
bj68
Fuck the "REGULATION (EU) 2019/1148" of the European Parliament and of the Council...denn
Kunst und Wissenschaft, Forschung und Lehre sind frei. Art 5 Abs. 3 GG
Kunst und Wissenschaft, Forschung und Lehre sind frei. Art 5 Abs. 3 GG
Re: Black flames
What makes the difference for the desired effect? The wave length?
Some of those sox bulbs are sold as halogene lamps...
Some of those sox bulbs are sold as halogene lamps...
"Es lebe die Freiheit!" (Hans Scholl)
- mgritsch
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Re: Black flames
Only low pressure lamps emit the narrow line spectrum that can also be absorbed and results in the „black flame effect“.
In high pressure lamps the Na atoms interact forming bands which results in a broadening of the lines and eventually a more or less continuous spectrum. Check it, most street lights (especially on city highways) these days are Na high pressure. You don’t get black flames.
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Re: Black flames
... and you don't see the shadow of the flame on the ground...