Marcus, a 9th grade student, heard that the students in the class were learning about the different properties of fire. “The crazy thing is, I had chemistry for fourth period,” she said. “I was supposed to be in that class too. We already did that experiment the week before and nothing happened.”
Marcus explained the experiment involved making a flame change color. “It was kind of dangerous when he did it but he was very careful,” she said. “I'm guessing it was the same way with this.”
Marcus said the teacher told her class it was a mistake with the alcohol he was using in the experiment. “I think that while he was pouring the alcohol in, the fire caught onto the bottle by accident," she said.Yet another incident where there was a combination of:
- fire
- alcohol being added to the flames
- from a bulk alcohol container with
- students being too close
Another reminder that the American Chemical Society's Committee on Chemical Safety specifically asks teachers to "Stop Using the Rainbow Demonstration."*
*The indication that it was a Rainbow-related is this comment in the New York Times story: "One of the injured students, Elizebeth Diaz, 15, said the chemistry teacher was conducting an experiment to demonstrate how an atom goes from ground state to excited state."
Again I wonder: where do teachers learn this particular demo? I know Shakhashiri wrote it in some lab manual, but I've never seen his manual in a high school classroom. It is not ubiquitous the way certain books are (every high school has a crate of unwanted Ayn Rand novels somewhere, for example, they just appear by magic). I never took education courses so maybe they teach the Rainbow in there? I just wonder how the tradition of the Rainbow has become so established, and I've still not managed to learn anything about how it propagates to new generations of teachers. I've taught at multiple high schools and generally I'm not handed a big book of experiments to do. Maybe my experience isn't typical but I still want to know: where does the Rainbow come from?
ReplyDeleteThere is a book called "a demo a day" that (I think) has it. Its made by Flinn scientific, could be more popular in HS level teaching.
DeleteGoogle.
DeletePeople change when the pain of change is less than the pain of staying the same (TM)
ReplyDeleteMethanol, and boric acid or metal salts, is an excellent demonstration, and the only one for which I use methanol as a fuel.
ReplyDeleteTeach the teachers to do it correctly, and they are modeling safe solvent use at the same time. How many charcoal lighter fluid accidents happen a year?
The 'Rainbow Flame' experiment is performed in at least some of the annual (since 1981) Michael Faraday Christmas lectures.
ReplyDeletehttps://chem.utah.edu/community/faraday.php
Chemistry professors Ron Ragsdale and Jerry Driscoll performed (in top hats) the lecture more than once. 2017 has a different crew of 2. The U tube condensed version from 2010 (starts in 1st minute):
https://www.youtube.com/watch?v=Bipu2DyN4oo
They use petri dishes with methanol and salt, and ignite. Salts were among others KBr and LiBr. One changes color as it burns from blue to red.