So reading this thread about a jar of nicotine in a high school chemistry lab got me thinking about my high school chemistry experiences, and one thing that stood out was a totally impromptu, but very illuminating (at least to me) demonstration of chemistry in action.
It was probably 1988 or so, I was a sophomore in high school and I was in chemistry lab. I don’t recall the actual experiment we were doing, but it involved some sort of iodine compound that wasn’t water soluble. And of course, it being an all boys school, there was a great deal of screwing around involved. During the course of the horseplay, my shirt got splashed with this iodine compound- water would NOT remove it. And my shirt was a striped pattern of pastel colors and white (hey it was the 80s!), so dark brown stains stood out like crazy, ruining a shirt I actually liked.
So I had gone to the bathroom and tried rinsing it out, and was walking back to the lab sort of dejected looking, and happened to walk past the chemistry teacher’s little lab office area where he was doing something while keeping an eye on the rest of the lab. He asked what was going on, and I showed him the stains on the shirt.
This is the part where it got interesting to me- he says something like “Ah! An opportunity for chemistry in action!” and grabbed his Merck Manual, and looked up the reactions for the iodine compound we were using. He found one that resulted in colorless end products that also used some stuff we commonly had on hand in the lab (I can’t recall the actual compounds 30-something years later!), had me take my shirt off, applied the second compound, and like magic, the stains disappeared, never to reappear.
That’s stuck with me for three decades now as the most practical demonstration of chemistry I ever had- far more down-to-earth than anything else I had.
What are your best/most illuminating educational demonstrations like that?
In seventh grade I used to stay after school and clean up my science teacher’s room for him (He was a really nice guy). The subject earlier in the day had been taste – we took turns closing our eyes and pinching our noses shut and a partner would stick an approved substance in our mouth and we would have to identify it. Very poor success rate, overall. That afternoon, during clean-up time, I expressed dismay in the results and questioned if the process actually worked. Experiment time he exclaimed, so I pinched my schnozz as tight as I could, closed my eyes and opened my pie-hole. I chomped down on what had been introduced and postulated “celery.” Released my grip on the old honker – Holy shit! green pepper! I’m rolling on the floor, choking and laughing simultaneously. Maniacal laughter from Dr. Research; a white lab coat and a full moon in the window with bats flying around and the image would have been complete. A successful afternoon’s work.
While learning firefighting while in the Navy, we were taught that one material rarely found on Navy ships is magnesium. It can burn and at a very high temperature. The class was then taken outside and the instructor showed us a wheel that as use on Indy cars at the time. Using a flare, he ignited the wheel and we used our training to put it out. Before the wheel was lit, I noticed that it was stamped with Gilmore Racing. It very likely that wheel had been on a car driven by A.J. Foyt, one of my racing heroes at the time.
Another one (prompted by @burpo_the_wonder_mutt’s taste experience) was a college biology lab session. Most were horribly dull and frustrating, because the equipment wasn’t clean enough to show good results.
One day, our lab TA decided to do something fun- it was a sort of physiology day, and a fun little experiment was that she had a whole bunch of little pieces of paper that had various chemicals applied to them that people had genetic sensitivities for tasting/smelling… or not. It was fascinating to see some people stick the paper on their tongue/smell it and react, while others were like “Wut? This tastes like paper.” Until that moment, I had NO idea how dramatic some of these were; there was a preservative of some kind that I could taste as a weird sour/bitter flavor, while most people in the lab were completely unaware of it. Similarly, there was some other chemical that I couldn’t taste or smell, but a handful of people were totally disgusted by it.
Until then, I assumed that the vast majority of people (like 999/1000) perceived things to taste the same, but that’s just not the case at all- it was like 20-30% of the lab that could taste them (or not) for a lot of these chemicals.
Not exactly a formal demonstration, but in a chemistry class freshman year, I spilled whatever the solution was on my shirt sleeve. When I got back to the dorm, most of the sleeve was gone. It’s been more than three decades so I don’t remember what the solution was but it was very effective.
I studied electrical engineering in the late 80s/early 90s, specializing in telecommunications as it was called back then (Nachrichtentechnik in German, which also sounds a bit obsolete now). This included a course called electro-acoustics, one which I was especially looking forward to, because I was and still am a big music fan, but without inside knowledge of the production and inner workings of recording music and other sounds. The highlight of the course was an excursion with our prof to the sound studios of the already venerable WDR in Cologne, just around the cathedral. It included the sound recording studios (with demonstrations of multiple sound effects, either by machine or acoustic means, like echo chambers), the big broadcasting hall, and especially interesting, demonstrations in a soundproof room. The latter one taught me a lot about the importance of room ambiance for reproducing sound.
ETA: I didn’t follow this road in my career, instead I specialized in IT and computers, so that part of my education was only a kind of fun hobby interest of mine.
One of the most memorable was in high school chemistry. The teacher was demonstrating how the speed of a chemical reaction was dependent on surface area.
He had a burner going, and plopped a block of wood on it, pointing out that the wood did not catch fire quickly, just charred around the outside, because almost all of the wood was on the inside, and was not reacting with the oxygen in the air.
He then took some wood shavings, and sprinkled them over the burner, saying that if you cut the wood into thin strips it would catch fire and burn, and you could see them burning.
Or, he said, reaching for a squeeze bottle, if you ground wood into fine particles and aerosolized it, it would burn very quickly indeed. He squeezed the bottle across the flame and sent a fireball 6 feet.
I remember this happening inside the classroom, but that can’t be right. We must have gone outside…
Could have been; what he did was dissolve it in some water, and squirt it on the stain, and it pretty much did exactly what the video showed.
At any rate, it was the sort of practical chemistry demonstration that stuck with me.
Had I been him (he taught biology as well), I’d have done something similar when we covered enzymes- I’d have got malted barley from the homebrew store and basically mashed it. It’s kind of shocking when you’re not expecting it how it goes from starchy and thick to thin and sweet due to enzymatic action.
The one that’s stuck with me longest was 5th grade and our teacher had us write the instructions on how to make a peanut butter and jelly sandwich as clearly as possible. We wrote them out, turned them in, and a few days later he demonstrated our instructions.
By the end of the session, there was peanut butter, jelly, bread, and bread everywhere as we had not been clear (“spread peanut butter around.” “put the bread somewhere else” “get a jar of jelly and put it on a loaf of bread”) or the instructions were out of order. I learned. I’m still not great at writing directions, but I am much better at it due to that demonstration.
My first one was in an 8th grade science class. After the teacher collapsed a couple of empty gallon oil cans by hooking up a vacuum pump (he got peeved because volunteers didn’t guess that ambient air pressure had crushed them,) he got out a bell jar. He put a glass dish of plain water inside, and he started up the vacuum pump. He narrated as the pressure drop lowered the water’s boiling point. What blew me away was that, with the water boiling furiously, the evaporation lowered the temperature, and a disk of ice formed on top of the boiling water. Wow.
The second one was a trick a pharmacist told me about. If you make a little mound of potassium permanganate with a little crater in the top, and pour some glycerin in the crater, you’ll get a fiery volcano. It even works in cold weather, on snow. The dense purple plume is really dramatic on the neighbor kids’ snowman.
I have three, though they were all done by pupils without permission!
Our physics teacher showed us static electricity via a Van de Graaf generator and made someone’s hair stand on end.
Then he left the room to get something.
So we formed a human chain between the generator and the metal door knob and shocked the teacher when he came back…of course the electricity went through all of us too!
The same teacher told us that sound could pass through wood as well as air.
We didn’t believe him (how could solid wood vibrate like air does?)
So he got several of us to put our ears to the top of a large wooden bench, then tapped the bench gently. The pupils said they could hear the knocking.
There were still doubters (we could hear that through the air, Sir), so he got another group of pupils to rest their ears on the bench. But before he could tap, somebody slammed a heavy text book on the desk. Every listening pupil leapt up in shock!
When we finished laughing, we agreed the point had been made.
The chemistry teacher did an experiment with chlorine in a glass container. (I don’t remember what…)
He warned us that even a little chlorine was dangerous and we should be afraid of it.
At this point, the toughest kid in the class announced “he was not afraid of anything” , strode forward and took a whiff of the gas.
He collapsed and had to go to hospital (he did recover.)
In a physics class, the Prof asked for a stooge for a demonstration of distribution of force. I was up front, so I stood up. He had me lay my hand flat on the table, put a lead brick on top of it and took out a hammer. He gave the brick a pretty good whack. Felt nothing, but took the opportunity to make this face: gilliam8.jpg (360×254) (wp.com)
The room erupted! What did I learn? Never pass up a chance for a good joke.
In High School, my best friend had this real nice, expensive bomber jacket, but wasn’t too careful with it. He tossed it in the back of his car. One day, he had to get a car battery, and put the old one in the back, kinda half on the jacket.
It was both amazing and sad to watch that beautiful jacket slowly dissolve over the next several months. He even cut away the ‘bad’ parts, but the spread of the battery acid was unrelenting. Beyond repair.
, strode forward and took a whiff of the gas. 
