Activation Energy (and exploding bags of Chlorine) - Periodic Table of Videos
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- เผยแพร่เมื่อ 2 ก.ย. 2020
- The Professor discusses activation energy - and we flash some light onto bags of Chlorine and Hydrogen.
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The shelves quietly burning in the background was a nice touch.
legend has it the prefessor has been sitting in the room for 24 weeks now
For quarantine, I guess hahaha
He seems like he’s ok. He’s got plenty to read after all. Be well Professor 😺
I hope someone is coming by each day to water him and turn him toward the sun.
So, lotteries tend to be endothermic since the number of tickets you'd have to buy to ensure a win typically costs more than you'd win.
Yup. Except on some roll-over weeks where they become exothermic.
Endonumismatic
Never knew liquid O2 was magnetic. You learn something new every day. :-)
Doesn't have to be liquid, either, but it's hard to see it with the gas.
Well, paramagnetic but it’s still fun
In fact, almost everything is, just not ferromagnetic. Look into diamagnetism and paramagnetism! Some elements repel and some attract magnets, although very weak:) We have all been thought its only nickel, iron cobalt that we can get action... but that’s not it!
You can figure that out basically for any simple molecule like O2 by drawing its Molecular orbital chart. if u got some sophisticated computer program you can do it for much more complicated ones (those are scary to look at)
A hugely important example of a catalyzed reaction that has has huge activation energy but is also endothermic is the Haber-Bosch ammonia synthesis process. It's one of the most important discoveries in history, and has led to the 1-2 BILLION people (maybe more) being able to survive by making it possible to effectively pull nitrogen out of the air and put it back into the ground to be used as fertilizer.
3H2 + N2 = 2NH3 is an exothermic reaction, but it has such a high activation energy that it was basically impossible to keep it self-sustaining with heat alone. Haber discovered that an iron catalyst reduced the activation energy enough to allow the reaction to proceed at manageable conditions. Bosch is the one that scaled it up from bench scale experiments to industrial scale. This was over 100 years ago.
It's one heck of an extreme setup to make this happen. It's been a while since I built one of these, but if I remember correctly, temperatures in the reactor need to be anywhere from 900-1000F (482-538C) WITH the catalyst just to keep reaction going, because of the high activation energy. However, once you do get the reaction going, because it's exothermic, the heat released from the reaction sustains the reaction. Thus, you need some sort of independent source of heat (we used electric heaters) to initially kick off the reaction, but then you switch them offline when the reaction gets going and the system stabilizes.
It was an interesting engineering challenge, that's for sure. Even though the temps have to be that high, you want them to be as low as you can get, because the equilibrium ammonia yields are favored by lower temperatures because the reaction is exothermic. Because the number of product moles is half that of the reactant moles, higher pressures also favor greater yield. I think our reactor operated at 950F (510C) and around 2000 psi (138 bar), but probably 50% higher pressures would be preferable. There's are serious pressure vessel considerations when operating at considerations like that, though. The reactor has to be at least 9-Cr, 1-Mo steel to resist hydrogen embrittlement which increases with temperature. 304 or 316 stainless have better embrittlement resistance but have lower tensile strength, meaning a thicker vessel. And stainless may cost more depending on availability of materials. And then there's the fact that you have to cool the product stream down to about -20F (-29C) to liquefy and remove the ammonia before recycling the unreacted H2 and N2 back to the reactor and having to heat it back up to 950F. Lots of staged heat exchangers.
I basically designed and supervised the building of that entire system (it was a pilot plant but still fully functioning) myself...at the age of 27-28. That's not to flex on others; that's to say to my fellow engineers that you can do amazing things if you're willing to put in the effort to learn what's going on. Don't let anyone tell you that you that something's beyond your grasp. You'd be amazed how much you can learn if you just open a book and then keep asking yourself "And how does this work? And this. And this."
I would give this comment a thousand likes if I could! Cheers! 😎
Amazing comment should be pinned. Thanks for the insight to the complications and considerations that have to be made when actually taking a reaction from theory to technical application.
To get a bit furher into theory, the main problem with the Haber-Bosch-process, taking the huge activation energy aside, is the negative reaction entropy, which sets a temperature limit to the whole reaction.
Despite the use of a highly advanced catalyst and tremendous pressures, to get anywhere near useful reaction rates, engineers have to go to such lengths as to operate the reaction near this temperature limit, where the reaction reaches equilibrium very soon. So the cooling step is essential to separate the ammonia from the remaining hydrogen and nitrogen.
Typo in 1st sentence -- I think you meant exothermic where you have endothermic, like you have later.
Exploding bags of chlorine made me say "Wow!", and then "Why's he doing it right over the fire exit!?"
Makes perfect sense! That's if there's fire the fire could exit via fire exit.
The ironing is delicious
Because it would amuse Neil to see all the foolish flammable mortals trapped as the building burns down and leaves him behind, standing, smiling, bald, eternal.
Exploding bags of chlorine? Now you're talking my language!
What?
I was wondering about that. He was spraying hydrochloric acid on the nice lacquered wood cladding with that experiment. The university board must have been thrilled.
Bet it smelled nasty
Yeah! I was just scrolling through the U-tube recomendations and spotted the word "exploding" in the headline. Suits perfect a thursday evening, a must-clicker!
I love the small of chlorine in the morning, lol
That guy is amazing at asking questions lol
guess you can say he does a good job
The professor seems to be a catalyst for the chemistry outreach process.
Petition to get One Great VOOOSH! as an official measurement?
No, that is how the United States got in the measurements mess it is in.
I see a little silhouetto of a voosh.
Millivoosh! Millivoosh! Will you do the Fandango?
Thunderbolts and lightning very, very frightening me.
(Nanovoosh) Nanovoosh
(Gigavoosh) Gigavoosh
'cos it's metric, don't you know?
Magnifico-o-o-o
@@DaisyAjay wtf
@@DaisyAjay I laughed way too hard at this
@@DaisyAjay This was glorious, well done!
So happy to see Professor Poliakov! Hope to see him more !
ditto 😀
Sir Martyn
he is refreshing.
I’ve been subscribed to this channel for so long 😂 but always click fast for him.
"and the answer is..."
The professor's hair emits a fire supression field?
Students who don't study, either have high activation energy levels or do not contain energy inside.
ahh Schrödinger's student
Ah yes, the two banes of productivity: Procrastrination and depression.
No teacher likes the endothermic students.
From a physicist's viewpoint, it is also possible that these students who don't study have a very large moment of inertia. Their centre of gravity is likely to be the local student bar. :-)
I will use this when I teach
5:42. How to bring a smile to Neil's face.
runcycleskixc - He actually laughed at 5:23
I had to watch it twice, just to make sure. 😆
This is amazing. Wish someone had explained this so simply in high school chemistry.
Neil is one of the most fascinating and mysterious figures of youtube and I wonder if he knows it
This was an excellent question. It's essentially the difference between rusting or burning-one is slow, the other is vigorously self-sustaining. The autoignition temperature is also quite interesting.
All together now: WOW!
1:54 Dinosaurs Attack card being burned, I'll take that as a Hi to the Tims! Why card #25 though? Feel like the classic #5 Homeroom Horror would be more fitting.
Or #8, Crushing a Canine
Here I was wondering if that was now going to be sent to someone. ^^
This topic was a harder one to me to understand . This video helped me to get it fully understand clearly and easily.
This was an awesome video. It was all made so clear. I wish I'd had access to this kind of resource when studying chemistry at school.
I really like how Periodic Videos now have many videos about every topic, so they recomend many of their videos during every single video.
Quite fascinating the chlorine bag reaction
As a chem major back in college, this was a nice throwback topic.
Great explanation! Thank you.
2:03 I realize you have a lot of these cards, but this still seems cruel XD
It is not just cruel, it's downright heresy!
Keep 'em coming Prof Pol!
this is awesome!! we learnt this in class just this Tuesday! Hopefully our teacher will allow us to do the chlorine reaction
"Why doesn't my hair start burning?" Professor, your hair is already on fire.
You are a joy. Thank you so much
I knew all this from High School chemistry, but I haven't thought about it in 50 years.
This is a great explaination!
Thank you for sharing. Charles
Great exposition. Thanks
Another great video thank you
Wonderful video.
Thanks, now I know something new and at last, I understand a chemistry class more than 40 years ago. Greetings from Venezuela.
ITS NEIL AGAIN! Havn't seen Neil for a long time!
Neil is on almost every video.
@@xenonram Havn't seen Neil for awhile
excellent video, very informative.
A perfect way to start my day.
love these videos
I must say, I've been enjoying your channel for years now and I look forward to more years of videos.
A video that I think would be a real winner is one on Liquid Helium. I think most people don't know much about it and it's uses, so it would be a really exciting video for all the current and future viewers.
I loved this video! More theory like this please
My favorite exothermic professor!
Love this channel
Would be interested to hear more about catalysts and how they work (as hinted at here) and why they are often otherwise inert materials.
I wondered about that question years. Then I considerd heat dissipation and the solution appeared more intuitive. Thermal noise may occasionally result in sufficiently energetic collisions to oxidize combustible molecules well below the combustion temperature, but the heat generated in those reactions dissipates too quickly to sustain a chain reaction.
Never stand next to large quantities of high explosives.
@5:42 Seeing Neil standing there, calmly smiling at a ferocious reaction at arms length, is both reassuring of him knowing what he is doing, but also a bit frightening. What on earth can make him look nervous or excised?
Nice video and topic. Much appreciated. Seeing Neil is always a charming treat too, especially when he can be seen wearing those boots.
Burning a collectible "Dinosaurs Attack!" card @1:23 -- sacrilegious!
I'm sure this is some high school or 1st year university chemistry material but heck the Professor explained it so well
Professor Poliakoff is a treasure. Love him. ^^
Love the video, i always enjoy them : )
I love this professor
I like endothermic reactions. I love how simply mixing two things together can actually turn the mixture cold! It almost seems to violate the laws of thermodynamics because my first thought was that you can easily get that energy back out that was absorbed from the environment and repeat the process over and over. Turns out that isn't the case.
I feel a slight sense of pride in recognizing every single reference video used. :D Love your channel.
I'm glad you're okay!
Thank you very much for this video.
I am a firefighter from Germany and also trainer for our new recruits.
Until now I had a really hard time to explain the catalytic and anti-catalytic effects, which are important for various methods of extingushing.
Maybe there is a chance for a video explaining the anti-catalytic effects in general?
I love your videos. Thank you!
Chemistry, Biology, and Physics are my favorite subjects in Science. I just started appreciating Chemistry
This was a great video! Along with elements, can we get more videos on concepts like these ?
It's just so relaxing listening to the Prof.. Even my girlfriend likes these videos. Even if she's not as familiar with neither chemistry nor english in general as I am :D
That was a really great video. You guys should make more videos on other properties of chemicals, like enthalpy of formation, enthalpy of fusion, what enthalpy actually IS, vapor pressure, heat capacity, heat conduction, molar entropy and the list goes on. Heck, you guys could have an entire series just on these topics. And if you present them half as well as this video was done, it would make for some great binge watching.
I love this man.
Wow..that's very interesting! Always leaning something new..thank you!:)
I love your videos! I hope that one day I can be a chemist, that comes close to you!
9:56 "VOOSH!"
Holy sh... I read your comment EXACTLY when he said it!
PROFESSOR I'M A HUGE FAN OF YOUR HAIR😂
Professor I am the greatest fan of you
This reminds me of a video Richard Feynman did where he explained this and transitioned seamlessly into explaining how trees grow out of the air.
The paper burns spontaneously but it is too slow to observe (due to small no. of molecules possessing energy). That's why very old paper turns a bit of yellow.
Music at the end was soothing
How old is the professor now? He will go down in history as the best teacher I never had
he's 86
I miss Periodic Videos. I need 2 a week at least. Awesome fireplace Brady. Needs some "activation energy" in it this winter mate.
01:54 Burning a copy (or illustration thereof) of Ray Bradbury's _Fahrenheit 451_ would have been apt.
Just what I was thinking!
If Professor Sir Martyn is my online class teacher, I would never miss one
i watched your entire playlist of periodic table of elephants, and saw this i got excited.
So excited for another video with the Professor! Tell us more about the chemistry of catalysts!! Why Platinum? There are many elements with unpaired electrons. I know it's one of the elements used in our catalytic converters.
This would make a nice primer for an episode on hypergolic mixtures.
I'm happy ! Years ago I asked Pete License to perform the reaction between Hydrogen and Clorine gas. Now I saw it ! Neil congratulations !
Your fro on point bruh
AWESOME Reactions on this Chemistry-Videos!!!
The professor is fireproof.
Great sir..sir please make video on colours of elements and reason behind it
As a native Californian (now in NYC) I'm still sensitized to earthquake safety.
All those bookshelves chock-a-block stacked to the ceiling is a death trap. I still get nervous here in NY and the UK in people's homes have shelves with dishware precariously placed.
Thanks
Again you get my attention.
👏👏👏👏👏👏👏👏👀👁️✅
Next video? Try:
Film vaults can light off the same way. If the atmosphere is conducive, the film stock will spontaneously combust.
To give a bit more of an answer to Brady's question about reactions that don't self-sustain: the activation energy is the *highest* amount of energy during the reaction, so an exothermic reaction that releases less energy than it takes to get the next molecule up to the activation energy will not self-sustain. Easy examples are fire-resistant materials. The combustion of such materials is still exothermic, but the activation energy is so high that they won't burn on their own, and will only burn if they're surrounded by enough heat (say, a fire resistant lab coat in a furnace).
Neil is so completely unphased by his exploding bags hahaha
Also huge props to the editor for lighting those books on fire in the beginning
Please make more videos on organic chemistry, ones with green coats.
"When you eat a jelly baby/gummy bear, you eventually convert it to Carbon dioxide and water. But flames don't come out of your mouth."
This is by far the professor's best anecdote.
Unless you have GERD, then you FEEL you have flames coming out of your mouth. (Said as an occasional GERD sufferer!)
3:00 I love the fact that an explosive experiment is being done at an emergency exit
Vaporizing Cannabis, Canadian here and I love vaporizing cannabis, I have Ankylosing Spondilitis and it allows me to function.
Damn, there are a lot of books on your shelf. Have your read them all?
Activation energy = the motivation for something to get up and actually perform an action. Could be a chemical, could be a child, could be a coworker. Everything has an activation energy.
A reaction endothermic enough to make ice would be pretty cool to see.
A common misconception about catalysts is that they reduce the activation energy of the normal reaction process. What they actually do is provide an alternative pathway with a lower activation energy and the old process is unaffected.
By lowering the energy of the transition state... By default a different transition state because it interacts with the catalyst, what is your point?
Was hoping for more discussion of the Beirut blast in this video.
"Have you ever wondered, 'Why am I not burning?"
Well I certainly have now
If I could go back in time and had a choice, Dr Poliakoff would be my Chemistry teacher, and Dr Finkel would do Classics. Awesome 😎
Well cellular respiration, which if explained badly, is slow combustion (of sugar). So... in a way we are slowly burning.
If not for Periodic Videos, I would never know that a group of jelly babies (gummy bears) is known as a “chorus”.
I'm pretty sure that safety matches (the kind that requires the striker as shown in the video) have much more going on in there - perhaps enough to warrant a separate video?
One thing that I was thinking through this video was I wondering how much activation energy and what the catalyst will end up being for fusion energy.