The Hidden Science of Fireworks

I feel like some of the above video was from some of Veritasium's previous videos because they look somewhat familiar to me.

With that being said, the video does a great job explaining what happens in fireworks.

Dr Derek starts with making rudimentary black powder (gunpowder - not the modern, smokeless version as Derek explains at 8:30) starting with the initial recipe from ancient China and moving to a more modern 75/10/15 ratio of carbon/sulfur/charcoal and then to a commercial, modern gunpowder. 

From there, it's onward to testing the effects of container strength on the size of the explosion - first with a simple, cardboard tube then with a reinforced tube. He then brings in a fireworks manufacturer who explains the cardboard, spherical shells of actual fireworks and the method for launching them. 

Then a bit about the methods of triggering the shells - showing black match then the craft-paper-encased quick match - including how to waterproof that trigger and how that trigger moves into the fireworks shell itself and lights the stars to produce the color and flash.

Speaking of the stars, they move into the creation of the different colors due to metallic salts and showing the individual spectra of those elements due to their electron configuration. The expert does then use some methanol to step things up a bit. (Remember kids, don't use methanol...ever.)

And the video wraps up with footage of a drone flying through the fireworks finale. I'll admit...that's pretty cool and should absolutely be watched in high res and expanded size.

SPOILER: Spider-man's bad science

Update: Original video disappeared. I replaced it as of 1/9/22...and again 1/16/22.

Today's video - assuming it's still on YouTube when you get around to seeing this post - has a significant spoiler for Spider-Man: No Way Home, so I'm going to put the full post and video after the jump.

The rainbow flame demonstration

Repeat after me, folks, "don't mess with methanol."

This demo (procedure here) is done using ethanol which would be way safer - but not totally safe, of course. The colors aren't quite as brilliant and clean as those done with methanol, but as I've said before, methanol isn't remotely safe to use here.

I do wish that I had access to the CLEAPSS document, however, but it's behind a login wall. It's apparently free for schools in Great Britain but not 'round here.

Chemistry lab fire at Strive Prep school sends 4 students to hospital (and follow-up)

smh...smdh...methanol, folks...just don't use methanol at all.

AT ALL

Unless you are professionally trained in safe handling of methanol - and I'm going to say that I don't feel confident that I'm well enough trained to use methanol safely - don't use methanol in any demonstration.

Yes, it burns nearly colorless making it an outstanding fuel for flame test demonstrations, but that's also the reason it's so remarkably dangerous. The nearly colorless flame is too easy to miss when you go to refuel the flames. 

It's not worth the risk.

Denver 7 did some follow-up stories - including one where they show the rainbow demonstration and discuss the risks and safety requirements. I'll post those videos after the jump.

Hand Sanitizer Fires Are Invisible

Yeah, I guess hand sanitizer - mostly ethanol - fires are pretty hard to see, but I'm really glad that Steve Mould here goes into the dangers of methanol for the second part of his video.

If I haven't mentioned methanol to you yet, you should check out all of my methanol videos.

I guess that's one way to wash your glassware

That's my upload of a video I originally found here (warning, adult word in the link - video is school-appropriate, though).

So, what's happening here (I think)...

Clearly, something is burning. I don't see any fire, but the lighter lights 'something' inside the beaker. Because the fire is 'invisible', I'm assuming the inside of the beaker is coated in methanol. It might be ethanol or some other alcohol, but the fire isn't visible enough for me to think it's anything else.

The vapors burn, momentarily heating the inside of the beaker and pushing lots of gas out. Depending on the stoichiometry, it also uses up more moles of gas than it produces. If the water vapor then cools quickly enough, there's an even greater drop in moles of gas.

If the moles of gas inside the beaker decrease and the temperature decreases, the pressure is going to drop. That lets the outside air push the blue water into the beaker.

It's sort of like the ammonia fountain or the can crush demo, but this drop in gas moles is due primarily to combustion and temperature changes (I think.)

All that being said, the idea of igniting methanol vapors just seems stupid.

12 Texas preschoolers hurt in blast from color-changing fire experiment gone wrong

Source: KHOU.com

Stop. Using. Methanol.

From The Washington Post...

The teacher mixed boric acid with methanol, Foster said, and tried to light it on fire. Nothing happened, so the teacher added more alcohol and lit the mixture again. Then there was an explosion.

It's so frickin' simple, just stop using methanol.

Even the ACS knows it.

How to Make Rainbow Fire

Do NOT use methanol for demonstrations involving fire.

Seriously, no debate, no maybe, no 'ifs'.

Just don't use methanol at all.

And Heet absolutely is methanol. Their SDS says so. (Interestingly, it actually says it's 100% methanol; between 0.0006-0.0012% some second, proprietary ingredient; and between 0.0001996-0.0003996% some third, also proprietary ingredient.)

Some safety notes from that SDS...

• Highly flammable liquid and vapor - H225
• Keep away from heat, sparks, open flames, and/or hot surfaces. - No smoking. P210
• Ground and/or bond container and receiving equipment. - P240
• Use explosion-proof electrical/ventilating/lighting/equipment. - P241
• Use only non-sparking tools. - P242
• Take precautionary measures against static discharge. - P243
• Do not eat, drink or smoke when using this product. - P270
• Use only outdoors or in a well-ventilated area. - P271
• Container may explode when heated.
• Vapor explosion hazard indoors, outdoors or in sewers.
• HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.
• Most vapors are heavier than air. They will spread along ground and collect in confined areas (sewers, basements, tanks).
• Vapors may form explosive mixtures with air.
• Vapors may travel to source of ignition and flash back.
• Structural firefighters' protective clothing will only provide limited protection.
• Move containers from fire area if you can do it without risk.
• LARGE FIRES: Cool containers with flooding quantities of water until well after fire is out.

Seriously, just last week I was at the National Science Teachers Association's national conference in Atlanta listening to a presentation about lab safety. One of the opening statements was that we all know not to do the rainbow demonstration but that there's more to lab safety.

It was just an assumed, opening bit of knowledge that we should've ever do the rainbow demonstration with methanol. There wasn't any explanation given because it should be that obvious. There wasn't even an explanation of what the rainbow demonstration was because it's apparently chemistry teacher res ipsa loquitur knowledge.

Best Fire Tornado - DIY - no moving parts!

I've made fire tornados before.

I've posted about them, too.

But those required a bunch of fans or a lazy susan.

This one is even lazier.

It requires some glass cutting and not much more.

Don't refill your methanol container even remotely when it's hot...or warm.

Be safe, folks.

After the Rainbow

Stop it, stop it, stop it...

Methanol doesn't exactly burn invisibly, but it does burn with a flame that is light blue enough that it is really hard to see in daylight.

There are lots of ways to demonstrate electron transitions without using methanol which is entirely unsafe to use.

Check out more details of the dangers as well as safe alternatives to methanol in an article on Chemical & Engineering News.

Rainbow Fire Halloween Jack-O-Lantern

You know where you shouldn't get your science advice? Pintrest...and Facebook...and I'll add in Tumblr, too.

Yes, a pumpkin flaming with green fire would be pretty stunningly cool. The thing would terrify every little kid passing by...which is the goal of every Halloween, of course.

But the pumpkin would require the use of methanol.

Methanol is, as I have said a number of times before, bad...dangerous...deadly...

No good can come from attempting this demonstration, folks. I'm especially worried about the notes at 1:50 that says 'The colored flames last several minutes. If you want to keep it going, you'll need to add more alcohol.' DON'T DO THAT. Even if the flames look like they're out... Even if the pumpkin is still hot, it can catch the methanol fumes on fire as you go to refill your flaming, autumnal ball of death.

You might not die, but you might wish you had.

Invisible Racecar Fire?

Methanol is terrifying.

In the above video, we see - or rather don't see - fire engulf Rick Mears and his mechanic, but it's a fire that nobody can see. Methanol and its invisible fire strikes again.

Don't use methanol.

Methanol fire and explosion-awesome.flv

I've mentioned methanol as being horrifically flammable, terribly dangerous, and not to be used in a classroom (or at home either, in case you had any ideas there).

Check out this video showing infrared video of a fire on a methanol tanker...and the explosion that eventually results.

Children among 13 injured from Reno Science Museum explosion

There isn't anything funny to say about the methanol explosion from above.

Methanol is a fairly small, organic molecule with one carbon, three hydrogens, and a hydoxyl group (CH₃OH.) Because of its small size, methanol has weak intermolecular forces and is highly volatile meaning any liquid supply evaporates very quickly and easily. That combines with its high reactivity with oxygen makes for a marvelously flammable - hence incredibly dangerous - compound.

And it burns almost totally clearly in daylight - as you can see in the below video. This combination - highly flammable, nearly invisible fire - makes it a natural choice for demonstrations involving chemicals that change the color of this 'invisible' fire, flame tests with compounds like boric acid, lithium chloride, potassium chloride, sodium nitrate, etc.

It also makes it a horrible choice for those demonstrations because any open flame hits the methanol vapors which then explode terrifically.

I'll state this. Just about anytime you hear about a lab accident - in a high school or college chemistry class - I'll give you ten to one odds that it's a methanol explosion. Yes, there are other explosive chemicals, but methanol is the common, bad one.

I don't use methanol with fire at all. Nope...not with any open flame in the room in the least.

Rainbow Colored Flame(thrower) Science Experiment!

If ever you hear about a high school chemistry lab burning down, it's by way of methanol.

Seriously, pretty much every lab experiment that has a big, fiery death (or injuries) came from methanol. It's a lot of dangerous than this video makes it out to be - particularly because it's highly volatile and has a low flash point. The vapors are nasty and travel way further than you would think.

Of course, methanol does produce way better results in flame tests than would ethanol's yellow flame.

And it burns almost invisibly which can be really, really bad.

Be careful out there, folks, even if you're just blowing the methanol up all over your backyard.