What triggers a chemical reaction? - Kareem Jarrah

View full lesson: ed.ted.com/less...
Chemicals are in everything we see, and the reactions between them can look like anything from rust on a spoon to an explosion on your stovetop. But why do these reactions happen in the first place? Kareem Jarrah answers this question by examining the two underlying forces that drive both endothermic and exothermic chemical reactions: enthalpy and entropy.
Lesson by Kareem Jarrah, animation by Flaming Medusa Studios Inc.

[@2caiden4u]

i to love it when i pour vinegar in baking soda and my oven explodes

[@patrycjawanat4890]

lmao

[@rimuru1532]

This is fake lemme try it...

[@portelMakergD3948]

How did it work?

[@Jaydenpal987]

@@user-pz1gd3nv4n he exploded from the amazement

[@neptune-ru4rw]

I'm gonna do it todat

[@darshkd1686]

I love how he's casually like, " you know when you pour your baking soda into the vinegar jug and your oven explodes" me: _yep..._

[@jomocoker4137]

ikr lul

[@bananapopproductions1292]

#relatable

[@aanchaljha]

333 likes

[@baaarav]

#relatable

[@rottenroads1982]

That Green Squash Shaped Guy looks like a Gentleman. Give him a Top Hat, and he’ll be complete.

[@violent-firelight]

Thank you SO MUCH! 😭😭😭😭😭😭 you don’t know how badly I needed this and how much I’ve been looking for this😭😭😭. You really are the bast. I love you so much.

[@frosted1030]

Entropy is not disorder. It's the tendency, overtime, in an isolated system, to move toward an homogeneous state. Calling it "chaos" is misleading.

[@blackflan]

Jese Joon It is not exactly Matter that obeys it, the entire system obeys it, but only if we're analyzing it isolated.

[@SirRichard94]

You are wrong m8. Entropy IS a measure of disorder. More exactly de measure of the number of ways a thermodynamic system can be arranged. In other words, an ordered system does not vary much thus having low entropy, a chaotic system has a lot of variations an ways it can be arranged, so it has a high entropy

[@frosted1030]

Ricardo Rodriguez Homogeneity of high entropy is quite "orderly". Thus, the "chaos" concept is unsuitable.

[@frosted1030]

Jese Joon Matter doesn't "obey". This is not a sociological law or a choice, it's an observation.

[@danmcann94]

Ricardo Rodriguez you can say that entropy is a measure of disorder, but you cannot make any comparison where the 'chaos' from point A to point B has risen. some people compare entropy to your tidied room, that seems to be getting chaotic by itself (e.g. your clothes and your notes are scattered all over you room in disorder). but you cannot say that the entropy of your room has risen over the time! thats a completely false comparison! entropy IS fundamentally linked to temperature and gases.

[@playfishau]

化學反應是化學中非常基礎和重要的概念，除了酸鹼反應，還有以下幾種反應： 氧化還原反應：氧化還原反應是指一種化學反應，其中電子從一個分子轉移到另一個分子，產生氧化物和還原物。在這種反應中，原子的氧化態會發生改變。 酸鹼中和反應：酸鹼中和反應已經在問題中提到過，這是指酸和鹼的反應，其中產生水和一種稱為鹽的化合物。 沉澱反應：沉澱反應是指當兩種溶液混合時，其中一種或多種化學物質形成不可溶的沉澱物質。這種反應可以用來分離和分析不同的化學物質。 雙水解反應：雙水解反應是指一種化學反應，其中一種化合物被水分子分解成兩個分子，同時另一種化合物被水分子結合形成一個新的分子。 酯化反應：酯化反應是指酸和醇反應生成酯的過程。酯是一種常見的有機化合物，廣泛存在於天然和合成的物質中，例如油脂和香料等

[@mally1456]

but how and why does entrophy increase?

[@PingSpoofer]

How are people actually being serious about this video?

[@lanamotaz8903]

0:29 MOM I LEARNT A NEW BAD WORD IN SCHOOL CALLED THE E-WORD

[@rad123man]

Lana Motaz 😅

[@dravinashkalla2272]

😂😂😂

[@skipdocumentary5544]

Now i know what to bake for diner

[@brittaniewest]

great video!

[@aliqazilbash5231]

KrispyKareem! sorry couldn't resist, Her doughnuts make me go nuts!

[@anathiel21]

elbette, kimya, psikiatri açısından en en en mühim alan, bileşenleri moleküler bazda incelerken, 6-7 faz işlemden geçirmek, malesef ki, oluşturulan maddenin vucuda alınımında da, vucudu enerjetik olarak dönüşüm fazına alır, bu compoundlar işlenirken, en saf moleküller seçilmeli, en safları, reaksiyon kapasitesi en aksiyon barındıranlar yani, ve faz olarak da, çok fazla fazda bir kimyasal reaksiyona sokulmamalı, bunu umarım ileride yetişecek bilim adamlarımız çok çok daha iyi kavrayacaktır ... ve muazzam derecede şifalı ve yan etkisiz ilaçlar üretilecektir .

[@1810pacman]

Really good

[@Nalber3]

awesome channel!

[@freesk8]

Great video! Thanks!

[@seska1245]

Don't feel like this actually was explained very well

[@Tommykee999]

I just Though about why chemical reactions happen wow

[@formidablesloth1806]

I love you guys and gals.

[@gruboniell4189]

Do you not see that every reaction has a golf player??? You don’t see the pre-reaction is as important as the reaction? The action that causes the whole process is the observer

[@Hasegawa長谷川-w2t]

More science video please 😉 and thank you

[@frankt9156]

How can bond store energy when bond form it releases energy!!!!

[@Brillemeister]

Is...is that CGP Grey narrating?

[@Quintinohthree]

And then nitroglycerin is drawn wrong (0:51). It was going so well too.

[@thalespro9995]

Jokes 1: I was going to make a jump but they all of them argon 2. I was going to make a joke about sodium but Na 3. I was going to make a joke about chemistry but I didn’t think there would be a reaction Pls like so everyone can see I want enough likes so that someone sees it who lives by me and tells it to me

[@kalanrichardson6541]

disliked

[@thailander5572]

I still don't get what he was saying. could you explain again without using these words, Enthalpy Entropy

[@murshidanajnin3694]

🤭

[@pacresfrancis1565]

E

[@abezeth1597]

simply beacause every action has a reaction

[@DannyandPatty]

How does this not make a reference to Gibbs Free Energy?!

[@user-by7bx1kv6v]

جميل اذا هنا عربي اريد ليك

[@Markus9705]

Entropy is NOT the same as disorder. Argh!

[@hillcon45]

well it's a good way to explain it.

[@Markus9705]

hillcon45 Well, the entropy of a system is simply the heat in the system divided by the temperature. It is a measure of the number of specific ways in which a thermodynamic system may be arranged, or a measure of the unavailability of a system’s energy to do work. It has nothing to do with "order" or "disorder". An "ordered" system may have lower entropy than a "disordered" system.

[@hillcon45]

TheLeftLibertarianAtheist dG=dH-TdS, ordered system have low entropy. The analogy to disorder might be off I agree, but it's pretty accurate. Disorder is always favored, not by a supernatural force but by probabilities, for a system to conform in orderly structures it requires an other force, enthalpy. For example water is surprisingly liquid in normal conditions: the reason is hydrogen bonds an enthalpic force, while methane is a gaz because there are no hydrogen bounds and not enough enthalpic forces to force a more orderly liquid.

[@Markus9705]

hillcon45 Wrong. There are systems which are more "ordered" and still have higher entropy. Sixty Symbols explained this quite well a while ago: watch?v=vSgPRj207uE

[@danmcann94]

hillcon45 methane has no hydrogen bonds? methane has more hydrogen bonds than water xD

[@Abcdeee_p]

im 11 i dont understand speak in english mate

[@maswiyat_i]

use google translator

[@stevekwok8894]

i agree who cooks a hotdog with the condiments on it??? Plus who cooks a hotdog on a campfire?????

[@ellist6264]

first

[@NiTheGod]

never happened to me, thumb down jk

[@Nobody-U-Want-2-Know]

Who cooks a hotdog with the condiments already on it?

[@paulmahoney7619]

That guy.

[@deepga9961]

Greg Fulton Entropy And Enthalpy

[@bradenroberts6946]

YEET THAT HOTDOG

[@raiden6607]

Me

[@nicholasdebono847]

sorry greg

[@azumaki5229]

E

[@chanbbbbbbb]

“ exothermic reaction is more likely to occur than endothermic reaction, because it requires less energy to occur.” Why is that so? Doesn’t it depend on the activation energy for the reaction? Can’t an endothermic reaction have a lower activation energy than exothermic? 2:02

[@sylwiagotzman5422]

exactly! 100% right, and if it is rare for an endothermic reaction to have a lower activation energy than an exothermic one, it could be only because - since less energy then activation energy must be released when making bonds (that's the definition of an endo reaction) - you have fewer possibilities left.

[@bonob0123]

would have loved it if they included a few examples where entropy and enthalpy changes of different sizes pointed in the different directions versus the same direction to show how the balance of these determine which reactions occur spontaneously.

[@AMStephens7]

me right now 😵‍💫😵‍💫😵‍💫 to many smart words

[@lonelycrow113]

Boo why did my teacher makes us watch this

[@matthewprendergast9853]

People might relate entropy and disorder but these are different concepts. One way to think of entropy is via a probability distribution. If I am concerned with heat capacity/stability, I can think about the number of different vibrations that can be stimulated by energy. If I am concerned with reactions, I can think of the different states I can transmit through the TS or the "width" of my TS.

[@ValCronin]

This video is great if youre trying to confuse people.

[@hutshutrules123]

Val Cronin lol i know what they mean and even i got confused haha

[@ferranbedollaperez5147]

This video is really good since it explains clearly with the golf metaphor and the other examples, it mases it easier to understand and, also the animationas are pretty good and make the video more enjoyable and funnier.

[@helenareagan7448]

Wow! So much information! I love Ted-Ed videos! Definitely a lifesaver!

[@Mr.Jawad-USA]

Thank you so much for making such useful videos for students

[@mee5618]

what cause of chemical reaction?

[@StopYFGA]

this guy's mouth shaped like arrow

[@danmcann94]

great video, but i just want to add a few things: the potential energy stored in chemical bonds is internal energy, not enthalpy. but enthalpy is the sum of the internal energy and the product of pressure and the changing of volumes in the system (H = U + pV). the product of a chemical reaction has an internal pressure that leads to pushing it's volume away. that way it's performing an extra amount of energy. i always find it hard to image entropy. it's highly misleading when you define it only as 'a measure of chaos'. entropy is fundamentally linked to temperature. it tells us in which direction the energy of a system is flowing and it cannot be destroyed, it can only be created. entropy tells us that high temperature gases always flow into colder temperatures, not the other way around.

[@corgispotter]

can you explain me the role of the PV term in enthalpy? I mean enthalpy not change in enthalpy. I don't seem to find it anywhere on the internet

[@dakimuchi]

I was going to make a joke about chemistry but... I didn't think their would be a reaction.

[@namelast3836]

MILITARY-GAMING ur is so hilarious I'm laughing out loud haha 😶

[@dakimuchi]

Thanks I was also gonna make a joke about Sodium but Na

[@dakimuchi]

Thanks I was also gonna make a joke about Sodium but Na

[@kirkpreston8869]

This was the reaction I had as well (*there)

[@alexandrugavriloaia6531]

You have friends?

[@01jbeals]

My 4 year old is absolutely obsessed with TedEd. Whenever he stumps me with a question, I find myself turning to TedEd

[@wubcarp3319]

Mr Jarrah seems to think about food a lot.

[@dianacastillo8302]

Is the nitroglycerin molecule structure correct?

[@countytunavids]

Yes

[@heyitzrane3025]

1:49 That's not how cakes bake...

[@drd6482]

Gime sum kake #literacy

[@PingSpoofer]

I always trip and my baking soda and vinegar mix together then my oven explodes. Happens to my all the time.....

[@lexibroke5079]

I have exam it’s good vid ❤

[@willthomas7950]

I'm watching basketball ---- > Chemical reaction

[@JustHam-sw9fn]

I'm so confused. My mom had me watch this video and it didn't help at all.

[@MrKahlil1001]

Man you guys explain things perfect!, I Love Ya'll Videos, yeees, keep inspiring and teaching, We need it.

[@YouknowMimisParplaveOr]

Bruh, the unskipable ad is like 15 seconds long.

[@SuperSaiyan-tr7fz]

So, the conclusion of the vedio , other than understanding the laws of thermodynamics was. It is better to cook food on a log of wood in forest.otherwise you will end up creating chaos in your house. 😥🏚 😂😂

[@pancakefist4716]

no matter how many videos I watch , I still cannot understand entropy.

[@gmkbelanger]

It's the tendency to go from a high energy state (complexity, high degree of order) to a low energy state (less organised, less complex state). Example given in the video of nitroglycerin vs nitrogen gas at 0:38

[@evank3718]

I really got a good reaction out of this one

[@yohaijohn]

the hebrew title is wrong הכותרת בעברית צריכה להיות: מה גורם לתגובה להתרחש (תרמודינמיקה) ולא מה מתחיל תגובת כימית (קינטיקה, אנרגית שפעול)

[@gray560]

yep that's my cooking

[@comprehensiveboy]

OK, nice analogies, but what exactly is the hump an analogy for?

[@MsDreamGirl098]

+comprehensiveboy the activation energy it needs for the reaction to occur.

[@RAJBPATEL1]

Bon appetit.... Enjoy your meal. ;)

[@violent-firelight]

Thank you SO MUCH! 😭😭😭😭😭😭 you don’t know how badly I needed this and how much I’ve been looking for this😭😭😭. You really are the bast. I love you so much.

[@anonymousdetective3786]

Bonds don’t store energy, the atoms/molecules/functional groups involved in it do.

[@alexa_the_ai8810]

CHAOS CHAOS

[@ramshashankrayavarapu4590]

I wanted to crack a joke on sodium, but "Na" cause All chemistry jokes are getting lame, lets just barium.

[@dhanshyamkamath8493]

Good lesson😘😘

[@moffatmurage]

entropy? disorder? lmao what say you have a bunch of silicone atoms, and they bond to each other to form their crystalline lattice? isn’t it order from disorder and still entropy? wouldn’t it have been better if you said ‘entropy is a measure of the number of different ways a state can occur’?

[@imyasharya]

Please make a video on Redox reaction.

[@SG-SilverGaming]

It's ok my CBSE mate😂

[@imyasharya]

@@SG-SilverGaming It's been 2 years I asked it. I don't think I want a video on it anymore. 😁

[@SG-SilverGaming]

Ok,Salute for your impatience😂🤪

[@imyasharya]

@@SG-SilverGaming 😏🤣

[@sarahellie4113]

Crash Corse did one on that

[@sai-pq4rr]

wouldn't I be dead if my oven exploded im so Confuse☠️

[@chanfarishafi6467]

Hey super ! Your animation and that message Its like my imagination I can view my imagine in real with more explanation.. Super ..👌🙂🙂🙂🙂👌👌

[@harshilagarwal6295]

Oh boy

[@yujeong178]

대체 뭔소리노

[@BobanOrlovic]

I still don't get what energy is, it sounds like metaphysical nonsense tbh

[@dominusdone5023]

A substance or matter capable of producing movement in any form

[@abouttime837]

But why is there energy in things at all? And what is it that makes things require more energy?

[@hillcon45]

Energy comes from initial formation of the Universe, it is not created nor lost but only transformed. On earth the sun provides the energy, which is absorbed by molecules and atoms and triggers chemical reactions all the time. Photosynthesis is a good exemple of a way earth absorbs energy from the sun.

[@urmomasf]

Thanks this helps a lot for my schoolwork!! :)

[@rad123man]

keerah you got that right

[@pamelasanders4396]

What's the charaterstes of physical property and non-example of physical property

[@thequietone3903]

E

[@alkaasati2722]

E

[@Lutranereis]

What triggers a chemical reaction? Insert Tumblr joke here.

[@StardustAnlia]

Uh oh, Fine brothers, they used the word react

[@saadsohail8887]

they really made enthalpy change diagrams with a golf course lmao

[@Madmanxox]

Vinegar and baking soda? I must try this.

[@nicollasleoncio7517]

What are two chemicals that have low entropy and two that have high entropy? Also, explain why you chose them please!

[@shaam7405]

بالله وش اسم برنامج

[@adressepoubelle6488]

Entropy/enthalpy/energy are merely elegant mathematical concepts which the universe does not know of. The reason two massive objects attract each other is not that the universe wants to lower the potential energy of the system, rather, the mathematical concept of energy was defined so as to match observations such as gravitational attraction. You can predict the outcomes of complex chemical reactions using the linearity of those mathematical quantities with respect to the elementary building blocks of the system. But the behaviour of each elementary building block must not be explained using these concepts. Otherwise you could explain absolutely everything using the argument that "after all, if it happened, it must have increased the entropy of the universe".

[@clydeabbott87]

3:21 who does that? that hotdog on a stick just-

[@kevinhsieh5527]

yea i feel like that everyday

[@nakulpatel5095]

from where do they bring these examples!!

[@BenjaminOosthuizen]

My science class just got easier

[@MelissaFlaquer]

What about the cake...?

[@nugghies9517]

This is very helpful as I have a test on chemical reactions. It's easy to understand.

[@neptune-ru4rw]

I dont

[@marcanthonyhuang1973]

The fact that I take AP chem makes me very happy to see this video but also makes me cry because all that I have suffered.

[@sidd0405]

2:43 is that a real compound?