What triggers a chemical reaction? - Kareem Jarrah

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.

[caidenu]

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

[darshkd]

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..._

[bonob]

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.

[ferranbedollaperez]

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.

[Nobody-U-Want--Know]

Who cooks a hotdog with the condiments already on it?

[helenareagan]

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

[rottenroads]

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

[matthewprendergast]

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.

[danmcann]

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. 

[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.

[MrKahlil]

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

[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

[urmomasf]

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

[frosted]

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

[nugghies]

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

[mally]

but how and why does entrophy increase?

[nicollasleoncio]

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

[comprehensiveboy]

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

[imyasharya]

Please make a video on Redox reaction.