Energy & Chemistry: Crash Course Chemistry #17

[@crashcourse]

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: apple.co/3d4eyZo Download it here for Android Devices: bit.ly/2SrDulJ

[@Scerttle]

Was legitimately going along with the silent q thing haha

[@hamzakhairi4765]

same

[@xemmyQ]

You can find what "q" is in "Memoir sur la Chaleur" by Antoine Lavoisier and Pierre-Simon LaPlace. They were trying to describe in a quantitative way what happens when you mix two substances at different temperatures. They didn't really think of heat as a physical kind of thing, but more of an amount, or quantity, which in French is "quantite". So, q stands for the quantity (or amount) of heat which can raise the temperature of a body (gas, liquid, solid) by one degree. :)

[@reedkellner6447]

"Trebuchet" from the English: tree-bucket.

[@Juknn]

out of all of the different crash courses, Hank's has got to always be my favorite, the references and generally just the way he speaks is prone to never get me bored.

[@allfarewells]

I really believed him for a minute when he said heat had a q in the front. Lol

[@Nebula.]

Thank you crash course, your videos in chemistry, physics and history helped me finish high school, after many years of boring myself, getting teachers and my parents mad, i decided to be home schooled, apparently all I needed to A those tests were your videos, so again THANK YOU!

[@TonkusLee]

*Me taking notes while watching this video Dad: "Is that your teacher?" Me: "I wish!" Dad: "Then why are you taking notes?" Me: "He explains it better!"

[@kevinmoore2501]

This series, as well as the others are, a useful, great tool to learn. Kudos to you all for making these all.

[@HungeeKirbo]

These biology, physics, and chemistry videos are honestly amazing. They are helping me a lot to learn for my class in college. I just have one question for you. I know it is an old video and I might not get a response, but I am going to ask anyway. What are some studying habits that helped you learn all of this information in the first place?

[@Pieisgood9967]

Ummm... Hank? Your trebuchet is on fire.

[@Colonies_Dev]

I read it right before he said he wouldn't set it on fire

[@akap]

Sometimes I hear people say "I don't want to eat anything with chemicals that I can't pronounce." I wonder if they can pronounce half of the natural chemicals that make up their organic, preservative-free fruits and vegetables... My bet is: they can't.

[@thegamingwhovian8247]

+ComicConcept F'rinstance: α-(5,6-dimethylbenzimidazolyl)cobamidcyanide Better known as Vitamin B12

[@GregTom2]

I mean... we can't produce starch so it's off to a bad start.

[@sophiaruizuvalle2523]

JudaTheIsm they couldnt even pronounce the names of the chemicals secreted by their own bodies

[@crimsonmoon7848]

dihydrogen monoxide+=H2O rip them

[@drholton]

My response to this is "great I can basically pronounce anything so I don't have that problem".

[@kittmcintyre2853]

It took me a minute to realize Hank was the same Hank from the John and Hank Green. I'm researching video's to help my son with his understanding of science and all of a sudden I see the guys I took my teenage daughter to see live for her birthday at their Turtles All the Way Down tour. That's pretty cool and now I have the Sweet Caroline song in my head. :)

[@DrFaustPhD]

Lab safety episode? Please do this! :) In my H.S. chem course, we had to find the melting point of lauric acid. I was doing this lab (and a few others) during a make-up day, so I just turned the hot plate all the way up 'cuz I knew I could spot the phase transition on my graph and get it that way. Later, as I walked past, I saw the acid bubbling away. Yay, done! Then my eyes and throat started stinging. "Oh, right," I realized. "It's still acid, now it's just IN THE AIR!" O.O

[@ShelelleO3O]

I tried to say "qheat"

[@Royal0rchid829]

+Yutian lol

[@Amandanumnum]

+Yutian it's actually pronounced "queef"

[@ahsanarifeen7827]

Spell it phonetically and its spelled 'Kweet'

[@yarugt5392]

aman lmao

[@Hassan.M]

its yeet

[@joshd1914]

I wish he was my professor

[@yaeljoi535]

Same I would be so happy😂

[@isectoid9454]

+Joshua Desire isn't he?

[@subhabrataghosh3565]

not really

[@davidcooper7292]

Professor??? I’m learning this in high school

[@bananananana6205]

David Cooper im learning this in middle school !

[@tifelicity]

The soft 'because I'm a nerd...' 😂😂

[@guyonacomputer1261]

I love how they set the trebuchet on fire at the end anyway.

[@kallistiX1]

SPOILERS!!!

[@Shammer1]

+Guy On A Computer wow srsly mate

[@lukasg4807]

it's fake fire. just edited in

[@zackorsomething4015]

u so stupid

[@ahsanarifeen7827]

It would be better if they covered the whole trebuchet with fire instead of just one wheel

[@Frundan]

I love the fact that everything Hank said in this episode I actually learned in high school. Cheers from Hungary.

[@lynsikeye3714]

This guy teaches me two weeks worth of lectures in a few videos better than my Chem professor!

[@ethanj454]

Thumbs up for the Thought Cafe induced burning trebuchet at the end.

[@humixmusic4lyf]

BLOODY HELL, I can never get over how fast you guys talk. I mean I got used to it now, but still, at the end of each paragraph -ish (when you take a breather) i'm just like: WOAH! INFO OVERLOAD!! thanks for doing these videos, really helps me understand chemistry more. coz a-level chemistry is just . . . killing me :'(

[@mckenna8663]

CRASH COURSE MOTTO: Anything makes sense if said at a high rate of speed. Sense = Speed ^4

[@captainstark5496]

exactly

[@pagurotraduzioni202]

people are late preparing their exam - fast forward this reel everything is relative, after you listen it to 2x speed - Normal speed will be slow

[@aumediwibisana4613]

I know right. I understand this more than my teacher's explanation xD.

[@SpadaccinoLuciano]

Are you joking? I oft put these videos at 2x speed because I feel they're too slow. What's not to get?

[@victryismin89]

"oft"

[@maddygreenfield464]

oh how i wish hank taught my chem class. i might actually enjoy it and have a chance of doing well in it then.

[@MichelePandini]

I love when Hank says: "because I'm a nerd".

[@rileygoshow8512]

god bless your soul for saving my chemistry grade

[@DaisyKahwenga]

this guy is officially my new chemistry teacher

[@GuardianComplex]

This is possibly the single most informative video I have seen in months.

[@dandedude]

7:45 Watch the left wheel closely.

[@mohdshahmeer6203]

it was on fire

[@MakerBayfield]

it was on fire

[@paperguy859]

it was on fire

[@tarragonpowder8724]

Sadly not even kidding, Hank has taught me more about energy in this one video than my teacher in the last 3 classes. Now I’m preparing for the test we’re having a week after being introduced to this...

[@SuvrathHegde]

Awesome man!!! you explain far better than our creepy professor. Keep uploading videos. If possible do upload some higher mathematics videos.

[@TheHumanFlag]

Note that in physics classes movement must be done in the same direction as the force applied or else no work is done. Dot product in the equation is missing in this video

[@00wsmcneil]

2:06. NO. NO. NO. BREAKING BONDS DOES NOT RELEASE ENERGY. Breaking bonds is uphill, unfavourable, endothermic, requires an input of energy. If breaking bonds released energy and were a favourable process, there would be no such thing as molecules, all matter would just fall apart into constituent atoms, break all the bonds, and release all the energy to move to a more stable, lower energy state. Consider the simplest molecule, dihydrogen, H2. Its bond strength: 432 kJ/mol. You need to put 432kJ/mol of energy INto the system to separate the H atoms from each other and break the bond. Energy is required for a bond to break. Bond breaking: endothermic. Forming bonds is downhill, favourable, exothermic, releases an output of energy. If forming bonds were an unfavourable process that required an INput of energy, there would be no such thing as molecules, all matter would exist as atoms, because making bonds and forming molecules would move everything to a less stable, unfavoured, higher energy state. Consider the simplest molecule, dihydrogen, H2. Its bond strength: 432 kJ/mol. That means that two H atoms will spontaneously come together and form a new bond, moving to a lower energy state by releasing that energy, releasing 432kJ/mol OUT of the system as the H atoms combine. Energy is released when a bond is formed. Bond making: exothermic. Breaking the bonds in lignin and cellulose to form individual atoms of C H and O is uphill, unfavourable, requires an INput of energy. Setting the trebuchet on fire causes a chemical reaction of the lignin and cellulose with O2, which replaces the weak C-H and C-O bonds with much stronger O-H and C=O bonds in water and CO2, so that the energy input to break the reactant bonds is more than offset by the energy released by forming the product bonds. Energy is released overall because product bonds are formed, not because reactant bonds are broken. Breaking bonds is always endothermic, always requires an input of energy, never releases it. Forming bonds releases energy. An overall chemical reaction might be endo or exo, but if it's releasing energy it's because new stronger bonds are being formed in the products.

[@nar4925]

Stephen is completely right. You may read this en.wikipedia.org/wiki/Bond_energy. The misconception usually arises when people analyze combustion reactions in biological systems. For example, when your body "broke" glucose you obtain energy to sustain different metabolic processes. So people say (wrong) "Energy is released when breaking bonds. However, the complete combustion reaction involves the production of CO2 and water, thus new bonds have to be formed. The release of energy is due to the fact that more energy is released when forming CO2 and water than the needed to break the bonds in glucose.

[@classicalbhargav]

Stephen McNeil yes you are right, breaking bonds does not lead to release in energy, but what he means is the nuclear bonds. but again for breaking nuclear bonds you require some amount of energy. This is why there is something called a nuclear reactor. fission and fusion lead to release in energy ( when uranium splits ) or something like that. so what you said is right but in this context and in the context of nuclear bonds energy is released.

[@nar4925]

Bhargav Kulkarni in the minute 2.06 Hank is talking about chemical bonds.

[@classicalbhargav]

I would like to apologise, for my comment, I hadn't realised that he said bonds between atoms. probably my mind has auto-correct 😂😎. but yes in that case Hank is wrong. but I am pretty sure he meant nuclear bonds

[@wtfisggon7251]

???

[@rebelchem]

Love your videos - but at 2:00 I an issue. I have to mention that when bonds are broken... energy is always absorbed. Energy is then released when the new bonds are fomed. When they release more than they needed then you get energy out. The energy needed to get the reaction going is the Activation Energy.

[@DeathbyCacti]

I'm a young power engineer and i studied thermodynamics. It blown me away. With this science, I see the world from a new angle as everything is energy, its just crazy. It's weird thinking that my understanding of the universe was so wrong. :P

[@Sp33dgum]

The fire at the end was really distracting..

[@pewnit]

I thought more people would notice.

[@kg9335]

Ummm it’s animated.... after all his antics - how is this tiny fire, seriously distracting? 🙄

[@harrysBMXstunts]

Hey hank just to say thanks for being such a consistent uploader it really benefits on my grades. :-)

[@HeadlessZombY]

random adventure time reference with the crying mountain?

[@mymoviesup9480]

7:45 the wheel of the trebuchet catches on fire

[@cimonejackson1665]

you just saved my chem grade, Crash Course team!

[@sans_seraph_531]

Hank -- At 2:06, you said "some of [the bonds inside the wood that contain energy] could be broken, releasing that energy" but I wanted to point out that that is backwards. It takes energy to break bonds, and if you burnt up your trebuchet, the atoms whose bonds were broken would form new bonds, specifically ones that have less energy than they do in trebuchet-form, and that is where the energy of the fire comes from. Thanks for everything you did and continue to do.

[@olivee2966]

That silent q thing humor was the only thing that keeps me going in Chemistry because I got the joke.

[@HeavyMetalMouse]

An important thing to remember is that much of the commonly used sciences are Classical in nature (as opposed to Relativistic). In Classical Thermodynamics, energy is conserved absolutely, and this is approximately true to a very high degree until you start deliberately pushing the edges of Classical assumptions. One of the major focuses of General Relativity is to understand where Classical reasoning fails, why, how to correct for it, and what the consequences of the corrections are.

[@edwardmaximus5439]

"if you were paying attention" lol I like how that got my attention

[@calamariattack]

As a physics undergrad I'm obliged to point out that energy is the quantity that is conserved in any system, it is in fact "mass energy" which is always conserved ([E^2-p^2c^4] is always conserved, energy E, momentum p, speed of light c)

[@sarmientoenricomiguelv.562]

Who is watching this to purely understand and have fun learning to apply?

[@TheJonix55]

I feel so good because I learned all this this year (first year of high school) and it just feels good how it all matches up ^^

[@OverTheMoon891]

"Which is what would happen if I lit my trebuchet on fire which I will not do because it took like, 4 hours to put together! >:U" lol

[@allisont37]

right when you said that the symbol for heat was lower case q, MY DOG GROANED. PERFECT. also I still can't get my head around the amount of everything in the universe being constant. that's REALLY trippy.

[@ThatMiddleEastern]

I always enjoy watching these videos. Crash Course has become a hobby for me, and I spend a lot of time here. :D

[@sophiaruizuvalle2523]

ThatMiddleEastern i watched them just as a hobby, now i watch them to actually study, oh how times have changed

[@tomgardner7965]

These videos are so useful for A' level revision. I love watching them. I only have one critisim you guys need to do Crash Course Physics! And who knows what about Crash Course Classics?

[@shalinikarmarkar104]

PLEASE do crash course physics!!!!!

[@paulblasiman1818]

CrashCourse has pledged to do Physics if they reach enough funding from Patreon. Consider donating if able.

[@sophiaruizuvalle2523]

Shalini Karmakar your dream became true, and it's pretty awesome

[@jfreak3610]

I like how everyone has suddenly become an expert in this field, and feels the need to comment on every detail

[@HozAbubakir]

man you are so funny, you make everything more interesting, thanks for this great video.

[@DocsDota]

I do have a question regarding gravitation potential energy however...On a planet, everything that is "lifted" was given the potential energy back to kinetic energy as gravity is applied to it. What about on a cosmic scale, how celestial bodies interact with each other? Was the gravitation potential energy for every bodily atom in the universe created upon the first big bang/creation of the universe?

[@narutardednerd]

My understanding is that the universe could not have formed as we know it without gravity... so, yes. Here's a video about gravity and the formation of the universe: kzbin.info/www/bejne/faLXhoqvebdknMk It's not really directly about what you asked, but your question reminded me of it.

[@Toolofdeath]

Am I the only one that noticed the wheel catching fire at about 7:45?

[@ThisRandomWord]

nope. :)

[@omarabdelkadereldarir7458]

2:50 LOVED that part

[@jamesgreydanus4676]

Does the guy on Hanks shirt look like Van Hohenhiem of Light to anybody else? It would make sense since this is a chemistry show and Van Hohenhiem is an alchemist in the Fmab.

[@zonderafspraak]

You are correct that E=mc^2 does describe that matter and energy can be converted into each other. You could also say that everything in the universe is matter, since all energy could theoretically be converted into matter. However, because of the second law of thermodynamics (entropy of universe always increases), this will never happen. Thus, all things are energy since it would be impossible for all energy to be converted into matter.

[@Distaancee]

Yes, 'q', deal with it! i fucking lol'd. love this.

[@muemelification]

Ole did not say that there are no theories that are proven wrong, but that there are no proven theories. That difference is really important in science.

[@prodbytdash4013]

So if the amount of everything in the universe is always constant, then what happens to the stuff sucked into black holes?

[@evanknowles4780]

***** That's a great point, since black holes are holes in the universe

[@sharktailmusictm2536]

***** You should think of a black hole like a vacuumer, it is sucking matter and energy into into itself, but it do not disapear just like the dust do not disapear when you vacuum it

[@stephenfosterdublin]

I was paying attention. I enjoyed this most of all crash course chemistry. Thank you for slowing down a little and it was a very interesting subject.

[@kawalangdalawahan]

Qheat

[@mohammedalialnuaimi6102]

cheat

[@pranavivedula]

Thank you so much for this video! You made this concept very simple and easy to understand. Also, loved the humor - it made the video entertaining!

[@mbfreshmike]

Hank it's on fire for goodness sake!!

[@andrewwojcik21]

I'm looking forward to your video on entropy and its relationship to 'free' energy... great video, folks.

[@evilishness1]

@Thought Cafe: Thank you for not labeling the 'Thermal' box with a flame; that would be a chemical reaction, albeit an exothermic one.

[@evilishness1]

And then that word was defined in the video and my comment became less intelligent. Still, it remains.

[@markifi]

i like the summary at the end. much better with than without.

[@kobewankenobi8926]

anybody notice the wheel was on fire?

[@MissFiono]

I'm loving these resources. Nice little reminders for things I should have remembered from school for using at Uni. Isn't energy given out when bonds form though? You said the opposite happens at . Also internal energy was given the symbol U in my physical chem classes and textbooks.

[@wtfisggon7251]

Is it me or his trebuchet had a flame on the wheel towards the end?

[@deepakbellur9676]

Very attractive video. The pace was attractive for me, but some people may find it difficult.

[@nsaisamrit]

can you add crash course physics

[@ElectrixHeart]

Yaay you totally helped me with my physics test tomorrow :)

[@shubhramishra8698]

Who realized the fire at the end??

[@suramyashalvi8132]

my besties name is shubhra mishra

[@shubhramishra8698]

Hi! Let's be besties!

[@suramyashalvi8132]

Shubhra Mishra utube besties🙌🙌🙌

[@shubhramishra8698]

What's your real name? (Don't say anything if you aren't comfortable with it :))

[@Zepheriah]

Yes, mass is energy, as is heat, chemical energy and work (see 1:14). The confusing part is that energy seems to sometimes exist as a material (mass, massless particles), and sometimes as a pattern that a material has (heat, work, chemical arrangements).

[@missvoguene1]

Lol anyone else notice that a wheel of the thingy was on 'fire'?

[@GAliu]

Thank you so much! Your videos are saving my AP Chem grade.

[@blummie1215]

4:01 did he just reference what i think he referenced

[@brandoncolon986]

adventure!

[@samuxvnzl]

Actually, references are made by tought bubble.

[@punkseth1]

I was hoping someone would notice that

[@AccelSpeed]

adventure time

[@lightspeedius]

Thanks for the response. I find the relationship between space and energy fascinating. It seems space is a very particular "something".

[@albertbokor6643]

Is that an Adventure time reference at 4:02 ?

[@sachitechless]

+Bokor Albert I think it is. The guy is pretty geeky with some of his references.

[@melonrue]

+Rukia Shimazu More like the animators and scriptwriters and relevant. It's more them that creates the geeky in the nerd speech of the videos to hook us.

[@sachitechless]

***** I'm sure Hank is kinda geeky as well tho.

[@melonrue]

Definitely.

[@jtxc3]

Dude... I love this guy. Is it lame that I come here for my leisure time? haha

[@Sugarfoxi]

Say Trebuchet again

[@Zeyphir77]

Dear Hank, this is not Energy & Chemistry. This is Energy & Thermodynamics & PHYSICS. By the way ... I LOVE IT. DO A CRASH COURSE IN PHYSICS. NOW! (or soon :) )

[@jaymsleedan]

Ummmmmmm the trebucet's wheel is on fire...

[@lemonthesane]

They are the same thing. Matter is condensed energy and you can transfer energy into matter very easily. E^2=M^2C^4-P^2C^2 means you get more massive the faster you go, transferring kinetic energy to mass. This equation, incidentally, is why anything with mass cannot go faster than light.

[@FuzeIt]

hes just like his bro lol

[@ajduong]

I'm glad I'm not the only one who likes trebuchets

[@ZoeyLeow301]

he did notice the thing was on "fire" right

[@neenoo12345]

Thank you for making this video Hank! I'm so glad that a cool person, such as yourself is making these videos,, I mean, one of your favourite vloggers is helping you study? Doesn't get any better than that :')

[@nurhanis909]

nothing to complain except that he talks way too fast. XD

[@indyreilley]

I loved seeing the wheel on fire at the end :)

[@braedonwilliams7352]

This is going to be my saving grace in AP Chem next year.

[@loog9720]

7:52 HANK! HANK! YOUR TREBUCHE- How do you say it? Trebuchet? Trebucha- Wait, Grammarly isn't saying the second one is bad. -T IS ON FIRE! PUT IT OUT!

[@mikecarlson8229]

If you hold a strong magnet close to a steel ball bearing, but not touching, the magnetic force will be acting on the ball bearing. If you let go of it, the ball bearing will accelerate toward the magnet, and increase in kinetic energy until it collided with the magnet. Does this mean that there is a sort of magnetic potential energy somewhat similar to gravitational potential energy?

[@DannieGirlD]

why can't my chemistry teacher be this fun to listen to

[@GarethField]

He's pretty good, there's other good ones, an listening is just part :) prof. Brack is awweesome, and actually observing what you make happen in a lab is orgasmic :) rock on, dude!

[@ElitAcilan]

work done is not always mechanical. It could be movement of electrons through a wire under an electric potential, the main idea is work is uniformed movement of particles while heat is not.

[@pinkribbon708]

Crash course is Love, Crash Course is life

[@corythecreeperplaysmc8464]

+Cookiebear soon crash course will be live (I laughed at my own joke LOL(the only thing funny to me is because this is inside parentheses inside a parentheses))

[@evadcock]

I've been waiting for this episode for a while - catching up with my level of education :D Now I can direct people to this video when I try to explain this stuff.

[@MrWolynski]

Thank you for making these videos. I am learning how to apply many of these concepts to the theory of star evolution which is replacing the nebular hypothesis and fusion models.