Just thinking outside the box here: it might be possible to not use flames at all and instead direct a light source through a synthetic gemstone or a piece of stained glass and make the same observations with a spectroscope. Both stained glass and synthetic gems are doped with certain elements like chromium and strontium to produce colors. The down side is that you may not be able to get all the elements that are usually flame tested. The up side is that your synthetic ruby is probably not going to set anyone on fire.
While the starting cost might be an issue for some teachers, you can get a synthetic ruby (doped with chromium) for less than the list price of a bottle of chromium trioxide, and it has an interesting spectrum. You could probably just glue the pieces on a light table with black paint or paper to block out the light so that it only shines through the crystal.
I haven't actually tried the stained glass, so I don't know how that would work. I'd be glad to know if anyone else thinks this might be feasible.
From: ACS Division of Chemical Health and Safety [mailto:DCHAS-L**At_Symbol_Here**PRINCETON.EDU] On Behalf Of Samuella Beth Sigmann
Sent: Tuesday, June 25, 2019 11:50 AM
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Subject: Re: [DCHAS-L] [EXT] Re: [DCHAS-L] Letter to the National PTAregarding the rainbow flame demo
Yes. We currently do this as an experiment with aqueous solutions and get very nice colors with the chloride salts of K, Ba, Sr, Na, Li, Cu, Ca. They can even observe and measure the spectral lines with spectroscopes.
Sammye
On 6/25/2019 11:09 AM, Monona Rossol wrote:
100 years ago when I was in qualitative analysis, we did it our damn selves in the lab. We made saturated solutions and used a platinum wire loop to get enough liquid in the loop to see an nice clear colored flame. Do they still do that?
Monona
-----Original Message-----
From: Meg Osterby <megosterby**At_Symbol_Here**GMAIL.COM>
To: DCHAS-L <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Sent: Tue, Jun 25, 2019 5:18 am
Subject: Re: [DCHAS-L] [EXT] Re: [DCHAS-L] Letter to the National PTAregarding the rainbow flame demo
The KCl flame was very hard to see. I have done this demo with (wood stick) cotton swabs, wet with distilled water and the tip rolled in the solid. The color is bright and long lasting and the purple/pink in the flame is easy to see. It's the only way I know of to do KCl and get such a good color.
Meg Osterby
W831 County Road K
Stoddard, WI 54658
414-539-1543 (cell)
608-788-7951 (home)
megosterby**At_Symbol_Here**gmail.com
"It's better to be careful 100 times than to be killed once." Mark Twain
I have been following the discussion regarding the rainbow flame demo. My colleague Kim Duncan and I have collaborate to put together the following site related to the safer flame tests.
If you have any suggestions how to improve this page, please let me know. Please feel free to use this page in your communications with teachers.
I have done this as a microscale lab. I make the solutions before hand and never have the alcohol still in the lab. I use small candles and cotton swabs. It has worked safely but I can see where it can go wrong. I am going to try the method mentioned using long cotton swabs soaked in distilled water and dipped in the salts. If it gives the same results, I will switch to the new method and share with my colleagues. We have been told not to use methanol and I have only used it for this lab. I think the AP Chemistry teacher used it last year. I will be that teacher this next year and will look to see if methanol can be completely removed.
I agree with Peter.
What we do is soak cotton swabs (The long Q-tip type ones) in
distilled water for about an hour. Dip the end in the various salts
and get the same result when burning. Others use wooden stirrers /
popsicle type sticks and do the same and get the same result.
Perhaps we should be assisting those in the classroom with viable
alternatives for this and other activities.
Best Regards,
-Eric
On 6/22/19, pzavon**At_Symbol_Here**rochester.rr.com <pzavon**At_Symbol_Here**rochester.rr.com> wrote:
> One thing I notice about this letter and many other comments about
> this demonstration directed to educators is the frequent absence of
> guidance on how to perform it more safely, or on alternative, less
> hazardous, demonstrations that would illustrate the same principles.
> In my experience, it is usually more effective to provide alternatives
> than to simply say "don't do that."
> Decades ago, my then boss at Princeton University used to say to
> faculty members something along the lines of "I am not telling you
> that you can't to that; I am telling you that you can't do it in the
> way you have been accustomed to doing it."
> Peter Zavon, CIHPenfield, NY(on location in Cincinnati, OH)
>
> -----------------------------------------From: "davivid"
> To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
> Cc:
> Sent: Friday June 21 2019 6:36:30PM
> Subject: [DCHAS-L] Letter to the National PTA regarding the rainbow
> flame demo
>
> Here is a letter I just emailed to the National PTA. Let's hope this
> helps get some progress on the issue.
>
> Dave Lane
> Principal
> Clavis Technology Development
>
> -------- Forwarded Message --------
> Subject: Dangerous classroom demonstration
> Date: Fri, 21 Jun 2019 15:31:09 -0700
> From: davivid
> To: info**At_Symbol_Here**pta.org
>
> Dear PTA Gatekeeper
>
> I write to call your attention to a common classroom demonstration
> that
> injures students in several incidents every year. I hope that the PTA
>
> can help end this practice by informing parents and schools of the
> danger.
>
> The demonstration is typically called the "Rainbow Flame" or similar.
> It
> involves solutions of various metal salts dissolved in alcohol that
> are
> set on fire. The different metal salts give various colored flames,
> hence "rainbow flame". If alcohol is poured near flame or other
> ignition
> source the alcohol can suddenly erupt from the bottle in a phenomenon
>
> called "flame jetting". The jet of flaming alcohol can severely burn
> anyone in the path of the flames even as far as ten feet away.
>
> Here are some links describing flame jetting.
>
> Dangerous ÔFlame Jetting' Phenomenon Kills Hundreds Every Year
>
> Here are links to some recent instances of flame jetting that have
> injured students
>
>
>
> Links:
> ------
> [1] https://www.youtube.com/watch?v=kkBFG1mTSBk
> https://www.youtube.com/watch?v=kkBFG1mTSBk
> /> A Safer
>
>
> ---
> For more information about the DCHAS-L e-mail list, contact the Divisional
> membership chair at membership**At_Symbol_Here**dchas.org
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>
--
Best Regards,
-Eric
Eric W. Goff
Chemistry Educator
---
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Follow us on Twitter **At_Symbol_Here**acsdchas
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We, the willing, led by the unknowing, are doing the impossible for the ungrateful. We have done so much, for so long, with so little, we are now qualified to do everything with nothing. Teresa Arnold paraphrased from Konstantin Josef Jirecÿek (1854 - 1918)
Samuella B. Sigmann, MS, NRCC-CHO
Chair, ACS Division of Chemical Health & Safety, 2019
Senior Lecturer/Safety Committee Chair/Director of Stockroom
Chemistry
Appalachian State University
525 Rivers Street
Boone, NC 28608
Phone: 828 262 2755
Fax: 828 262 6558
Email: sigmannsb**At_Symbol_Here**appstate.edu
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