Aromatics & Cyclic Compounds: Crash Course Chemistry #42

What's that smell? Smell's like Organic Chemistry! This week Hank talks about Aromatics and Cyclic Compounds, naming their substituents, resonance, and common reactions & uses.
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
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Table of Contents
Cyclic Organic Compounds & Naming Their Constituents 1:06
Aromatic Compounds 3:02
Resonance 3:18
Naming Aromatic Compounds 5:05
Common Reactions & Uses 7:24
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[@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

[@5602KK]

Once again, we can find Hank Green saving my ass on a science test

[@haaniyahali3504]

Proud Hunter thank god for hank green :P

[@user-cp8fn5wo3u]

Proud Hunter hehehe me too chemistry#40 -#43 :)

[@oafkad]

"This is the same root as Bon Jovi." OOOOOH! "It's not." ...don't toy with my heart like that.

[@alyssaalcantara6739]

Hey, Folks! I believe everything he says so easily because of his credibility lol I’m so gullible

[@HabboBZIsTheBest]

Last minute crash course before my uni exams as per usual

[@NotQuiteMelvin]

How did it go?

[@Max_Jordan]

now back to ppap remixes...

[@abhinavajith92]

+Max Jordan lololol

[@Bastuun]

feel ya, bruh!

[@shivtiwari1878]

Nyaiffy I

[@ChrisThomasBone]

Hank, you and John need to be in charge of all education in the country. Seriously, if my high school taught chemistry half as well as you, I wouldn't have been constantly failing.

[@ZozziFox]

People are talking about uni exams whereas I just want to get through my high school chemistry test on hydrocarbons. XD

[@captainmisan259]

same 😂

[@yanyanshidae3078]

I KNOW RIGHT. mine's like two days away

[@ibettekim1640]

s a m e exams are tomorrow aaaaaa,,

[@chrisswaney9329]

Haha same

[@JohnSmith-sf8ms]

ZozziFox i

[@annitavelasque6273]

"If you payed attention..." I love this ending to all the videos! Thanks, Mr. Green! (;

[@sharonchase4802]

What I've learned from this is that chemistry is batshit bonkers.

[@kotonaiishida]

thank you so much for this video :) could you continue the series and add a video about substitution reactions like the SN1 and SN2 and E1 and E2 ?

[@yeshethubten9984]

I laugh at that Bon Jovi joke every time.

[@longshot606]

+Nika Cross Benjoin: Bon jovi, you can see where he's coming from

[@TheWaddle3]

I have been watching your videos for a month now and you helped me choose my major in college by showing me how awesome chemistry is. Thank you Hank!

[@aminarashid4263]

thank you so much I use crash course as a warm up before diving into the details. It's amazing how you guys script the information so both beginners and advanced learners can understand.

[@zj3777]

" just to make sure you're, like, good and solidly confused " XD

[@anubis2814]

I forgot how much orgo I forgot over the past 7 years since I last took them.

[@hidef9265]

How long will it be until you forget that you forgot how much you forgot?

[@anubis2814]

I won't find out that until I remember again

[@scarea2691]

@justine klent madanlo lol

[@melodysong1127]

I just had 3 hours of lecture on aromatics and cyclics... yet, somehow, as usual, crashcourse took 180 minutes of convoluted information and delivered it in a fun, digestible, 10 minute informative video. Thank you!

[@mtrps_]

watching crash course before my tests as usual, thanks guys!!

[@SebastianSzukalski]

I really, really like the texture on this blazer. Looks soft and smooth.

[@tangerine_z]

LOL! Ikr! It was hard not to notice.

[@Kitan3000]

It's so amazing how you cover exactly what I'm going over in Chemistry when I am being taught it. It happened with thermochemistry, electrochemistry, acid-base, and now organic chemistry. It's as if you made the videos specifically for me! Thanks for the awesome videos. :)

[@KimJong7hrill]

This video gives me flashbacks to Organic Chem as an undergrad. I drew so many aromatic rings that year...

[@Angelamica7253]

So thankful for these CrashCourse videos when exams are coming up. Definitely a concise but informative review of the overall topics. :D

[@JoeG9999]

Learned more in this one video than in half a semester of classes, thanks :D

[@worldinside3001]

Really amazing.... Listening and visualising simultaneously in short timing is because of crash course only... And that historical stories ... I love it

[@ananyasharma2834]

You are doin great guys! It was really very useful.. and is indeed to get back to my subjects during exams making em more interesting...❤

[@Jakes203]

that picture of drawing "Hank

[@kemiyoshida]

Thank you, this crash course was super interesting and helpful!

[@sathiyajeeve]

Its so cool to understand the basic

[@fashionholicable]

thankyou thankyou thankyou thankyou so much, this is just in time for my organic chem test tomorrow

[@sarapananvhon4509]

thanks for this i really happy withthis video it helps me to take advantaged about all the compounds here..

[@romantheflash]

This was awesome, I think I am finally understanding Hydrocarbons and also all those chemistry drawings I have seen around.

[@justinsunil2330]

Congratulations on 200 Videos!

[@shawnamcguire4150]

These videos are amazing

[@RWayneG]

Amazing, thanks, love the vids.

[@munchimadness]

Thank you for your video! You're the best! Just subscribed!

[@anzwertree]

LOL, those wacky carbon atoms have me in stitches.

[@arnabadhikary828]

dude...u speak so fast and clear!! ( compliment)

[@Yousef-pt3sp]

Their videos have this very relaxing vibe which is the only reason i watch crash course not any other educational channel

[@LuckyM318]

These are great! Ya'll should be life savers and include organic reactions into the mix! I'll love that.

[@nathanlee4844]

Thanks for the educational video, it was definitely great.

[@jyak27]

seldom do i call my mom, but i got so damn excited about science i had to call her (shes a nurse so we have this love in common). you da man hank. and a thanks to all the guys at crashcourse

[@krankkiwi]

I finally get addition, substition, condensation and aromatics thanks to these videos. Thank you! (:

[@HeatherHu]

OMG! Hank you just made me fall in love with organic chemistry!!!!

[@juswanth.t133]

Amazing!!!!!! My brain is melting

[@KaramKettanie]

6:18 i was literally dying to know.

[@vivian8707]

Thank you very much! This is really helpful! :D

[@haiggoh]

Good refresh on my high school chemistry! Thanks!

[@MaximC]

So beautiful, in every way. Thank you.

[@deproissant]

This video made a mention to Jovi, Java, and Sumatera. Easily my most favorite CrashCourse video even though I love John's field more

[@no0available0name]

AH MA ZING ! This is what is so hard for our chemistry teacher to explain in 45 minutes, you nailed it!

[@ItsCindyHey]

These videos really help me to understand chemistry names.

[@anshgupta8560]

I AM A HUGE FAN OF YOUR VIDEOS. It makes boring topics so interesting and fun with your 3D visuals and Hank is so humorous as well. I WAS WONDERING, CAN YOU ALSO DO A VIDEO ON ISOMERSISM AND OPTICAL MERISM, THEN ALL MY CLASSMATES WILL WATCH IT TOO. Right now you skip over so many topics in a chapter, so they don't wanna even check you out. Please do that, you will be a great hit. I promise....

[@qairastead3670]

Please please please do not stop doing this.... you are getting me through undergrad one video at a time.... also, I need next weeks video noowwwww

[@WWZenaDo]

Definitely a like on this one!!

[@cold4882]

This DESERVES my like

[@MonkeyDLuffy-xr4fl]

THANK YOU!

[@SweetChemistry]

good work

[@isabelchacko881]

it's so helpful 😃😃😃😃😃

[@micheller1555]

Great video :)

[@neliexp1]

Crash course video's like the ones on this channel are a good way to get to know the basics but it's a summary and therefore not detailed enough to pass your exams! For example the Huckle rule is not mentioned, just like the rules for aromaticy and anti-aromaticy and the fact that aromatic compounds don't undergo addition reactions. If Hank had to explain every detail it wouldn't be a crash course anymore but a college lesson. Just keep in mind that if you want to pass your exam, you better study from your books as well :)

[@Aditi_1319]

really love that sketch.....

[@mayankrawal1091]

Hank Green Blessed me !!!

[@headrockbeats]

Awesome reference to Craig Benzine at 6:40!!

[@trappleton]

I was quite literally just thinking about the science of aromas yesterday! Goodness. I still have a question: Does an aromatic material lose matter in order to give off a smell? Do incredibly smelly materials effectively have "half-lives"? Do radioactive compounds with half-lives have aromas?

[@andrewephron4389]

when you smell something you are smelling the paricles that are light enough to get into the air (usually gasses) so no they are not radioactive or loseing material the material is just going into your nose and getting stuck. as far as particularly strong smells they usually contain certain atoms or molecules, nitrogen and sulfer being the most distinctive. nitrogen compounds are some of the worst smelling molecules with plesant names such as putrescine, cadaverine, and Spermidine... i'll leave it up to you to decide where that is from!

[@andkon789]

happy 200th video crash course!!!!!!!!!!!!!!!!!!!!!

[@lil.ms.j7156]

You are a God send -_- I kid u not. Your always informative so nice to listen too cause your clearly passionate, keep it up! Thanks for the lesson ^_^

[@peacejohn6162]

nice pics

[@sarahmedouni8844]

+Peace John wow dude

[@tevolutionYT]

Now I am in Love with aromatics and cyclic compounds! ^_^ :')

[@samueljoshua7385]

+Mahir Muzahid me too!

[@taniyan7322]

You make me happy :)

[@BecauseWeCanTheChannel]

Thanks for helping me study for my Organic Chemistry final.

[@emiliatan2509]

Thanks!

[@genericusername562]

Wait. Hank has a degree in biochemistry, he knows about aromaticity. Being a ring with resonance is not where aromaticity comes from. Being a planar ring with p orbitals all the way around and having 4n+2 electrons in them where n is any integer is how a ring becomes aromatic. Other aromatic compounds include cyclopropenone (resonance structure produces 4*0+2 p orbital electrons), furan (oxacyclopentadiene) is aromatic (4*1+2 p orbital electrons), and borazine (4*1+2 p orbital electrons, and it isn't even organic). Meanwhile, compounds like cyclooctatetraene have the same kind of alternating sigma and pi bonds in a ring, but aren't aromatic. In this particular case, cyclooctatetraene actually bends itself out of shape because it has 4n (4*2) electrons, which would make it not just not aromatic, but anti-aromatic if it stayed planar. Anti-aromatic compounds are extremely unstable, so they tend to either not exist or find ways to avoid have a planar conjugated cyclic array.

[@deejaybundst1671]

in org chemistry i thought the term aromatic was used a little differently, and necessarily implies a carbon ring with resonance, so maybe he's trying to stick to the organic theme of this batch of episodes?

[@kaushiks7284]

ty for speaking fast it saves my time..

[@kartiktaneja7868]

Very nice

[@madisonmoore7830]

I am in Organic CHM part 2 right now and man I wished I'd known these videos existed last semester! I almost didn't survive that class but you explain everything so well

[@thg_2728]

at 7:00 he seems so happy and theres the little guy on his shoulder like "ahhhhwwwww" And then he's like "It's not," with that smile I lost it!

[@144pandagirl]

Wow...I didn't think it was possible to make a T-shirt and a suit jacket work together, but you pulled it off nicely.

[@manumohan3812]

thank you boss

[@somashakarm1844]

helpful at the time of revision for Exams point of view......!

[@diegonayalazo]

Thanks

[@muhammadharoot1143]

So nice sir

[@nikhilwardrobe]

huckel's rule and anti aromatic compounds deserved a mentioning !

[@npcKee]

Was that guy with the coffee meant to be WheezyWaiter? Also known as Craig *Benzine* (which sounds exactly like *benzene*)?

[@DavideousIII]

Should've talked about the 4n+2 rule

[@economicorderqty]

Huckel's rule

[@ajaikumar9813]

Yeah, ur right

[@FROPDESAI]

'It's also the same as Bon jovi! Not really!' - Hank Green, 2013

[@volodymyrbezverkhniy8687]

Quantum-mechanical analysis of the MO method and VB method from the position of PQS. The MO method and the VB method are analyzed using the principle of quantum superposition (PQS) and the method of describing a quantum system consisting of several parts. It is shown that the main assumption of the molecular orbitals method (namely, that the molecular orbital can be represented like a linear combination of overlapping atomic orbitals) enters into an insurmountable contradiction with the principle of quantum superposition. It is also shown that the description of a quantum system consisting of several parts (adopted in quantum mechanics) actually prohibits ascribe in VB method to members of equation corresponding canonical structures. Using the quantum superposition principle, the MO method and the VB method were analyzed and it is shown that they are in contradiction with quantum mechanics. Also, using the quantum-mechanical description of a system consisting of several parts, it is shown that the attribution of canonical structures to the members of the equation is incorrect. Therefore, both the MO method and the VB method did not describe molecules with chemical bonds but actually, a lot of atoms (of which the described molecules consisted). That is, in the quantum chemical calculations, the chemical bond was "lost". Therefore, in order to "introduce" a chemical bond into calculations and avoid conflict with quantum mechanics, it is suggested to postulate the existence of MO as a new fundamental quality that describes a specific chemical bond and is not derived from simpler structural elements. Quantum-mechanical analysis of the MO method and VB method from the position of PQS. vixra.org/pdf/1704.0068v1.pdf

[@kserious1]

Dude, get your freakin PhD and become a prof, you'd be amazing! This was a great way to review my biochem1 class 3 years later. I've been watching your videos for a while, great material, and it's great material I've been passing on to my students as well. Keep on keeping on!

[@mynameissarahred]

What do you mean "Seriously?!", the phène/I illuminate thing is wonderful and brilliant. :)

[@esthernaikuluinilagi172]

Awesome

[@jwn1387]

Hank, could you make an episode on Graphene. Thanks!

[@crafterman5833]

great video

[@crafterman5833]

who is watching this because of a exam i have one next week

[@Purumal1337]

i wish he had brought up benzaldehyde.. i used it in the lab a few semesters ago, and as soon as the bottle is opened it smells like almonds in the entire lab, it is the compound that makes almonds smell the way they do... instants christmas in a bottle :P (altho i wouldnt recommend ingesting it)

[@HaruCloudRider]

i just finish my organic chemistry B course, it was way more complicated than this, but it has lot of useful info in just 10 minutes :) nice chemistry snack

[@Stasisdrone4827]

Only wish that Crash Course touched a bit on the mechanisms of a few characteristic reactions, such as Sn1 and Sn2 mechanisms for Nucleophilic Substitution etc.

[@linhgabrielnguyen2952]

5:37 why that structure is named 2-phennylhex/ane not hexene ? The ring prepresents for the double bonds and CH is substitutent.

[@voveve]

Thanks to Ryan and Reese! :)

[@naniWithCamelCase123]

hey, technical question: in 5:40, why we call it 2-phenylhexane and not sec-hexylbenzene? they are identical in length, and also the -ene functional group is higher in order compared to the -ane functional group. please help!

[@3rror_dev]

Hank's amazing lol

[@victoriatucker6271]

This is my favorite crash course. Make biochemistry videos

[@michaelhenry6624]

I don't get why people complain about his speed, I always watch Hank in 1.25-1.5 speed. It makes more sense.

[@katherinethomas3654]

Cool

[@pankshu4975]

can there be a more detailed teaching on this topic like its preparation and electrophilic subsitution reactions?

[@aoconnor2933]

Hey hey... mothballs smell pretty nice. Reminds me of my grandma's closet.

[@calsta619]

I really need to watch every single episode of this chemistry course back to back and over and over again to learn these things, luckily I have a brilliant and cunning excuse not to, I'm fourteen and I am lazy.