Chiral examples 2 | Stereochemistry | Organic chemistry | Khan Academy

[@revu34]

Haha I could just listen to you talk all day Sal. No one will probably read this, but thank you so much for just existing.

[@medhanshkhandelwal6339]

i read your comment XD

[@ILoveyouxoxo93]

I sat through the lecture and felt like an idiot for nearly 2.5 hours. I listened to him once and I got it. Sal I love you so much! thank you :)

[@madeleinesilitonga9795]

tysm sal for the wonderful playlist, I've got exams coming up and all i have to do watch the whole playlist in 2x speed to make up for my wasted 1 month in school with the teachers being unable to explain as coherently as one video of yours. cheers!

[@markbrightwell3536]

Hi Sal, In the last example of this video, you state that 1,3-difluoro-cyclopentane is a non-chiral molecule. However, I believe that's true only in cis configuration. The trans configuration appears to be chiral. Thanks.

[@lynnp8485]

Thank you thank you thank you so much you don't know how much I appreciate you .. I've been feeling like I'm drowning bc I was behind and exams are coming up but you explained this in such a simple way. Bless you I hope you have a great day and a great life :) thanks for doing what college professors can't LOL

[@sihanguo9752]

you are way better than all of my chem profs who took decades to study chem and still did not make us understand Chem!

[@richardford3061]

I wonder how many times Sal has said "let me use a different color here" throughout the years

[@no_name4585]

He forgot to mention that an achiral molecule with chiral carbons, like the last example, is called a meso compound

[@georgieacero7043]

theAlchemist398 thank you so much, was just wondering that. Appreciate it!

[@Jonathan-rf5cp]

Also, it's only a meso compound if compound is cis. The way he drew it, it is impossible to tell cis/trans.

[@haweya-]

I watch your videos before I go to class, and everyone thinks I'm a genius because I understand when the professor explains it hahaha.... But thank you, I love your videos, they make my life easy :)

[@monicanokubeka3128]

I'm a student from South Africa. Your lessons and teaching are so understandable. Thank you sir.

[@Philpq90]

Thank you so much! I already took Organic Chem and now in Biochem and I still don't know the definition of chiral, but now I do!

[@MaeveSunderland]

This video made an entire week of lectures make complete sense.

[@ChilangaBanda08]

Oh my... you are so clear explaining, I loved the last example where the molecule as a whole is not chiral but it has Chiral Carbons.... Greetings from Houston, Texas!!!

[@WeNeedAProperName]

I literally LOVE you,I cant tell you how grateful I am for your videos!Thank you so so much,I doubt that you are reading this but I feel like I have to repay you for all you have done for us!Do you probably have a P.O-Box? Thanks to you I somehow started liking chemistry (:

[@korecfilip]

I think he should say that the last molecule is a meso compound and show that the molecule itself has a vertical axis, that means it is superimposable, and in fact that's a definition of a meso compound.Just a detail.But anyway great videos,easy to understand.Greetings from Slovakia

[@epicfail23]

Free education at its prime

[@OnthLvRoad]

THANK YOU SO MUCH ! ! I'm watching your video from Belgium ! And I think i'm gonna come here often ! Really, thanks a lot !

[@Riku4567]

Thank you so much! I was trying to understand this from the book, but it made no damn sense what so ever, then I saw this and it just clicked! You're amazing

[@spieo]

There are many ways to educate yourself for free, it's often just the degree that people "pay" for. If you're upset with your/a university then leave it and continue learning on your own; it will just be more work proving yourself apt in your field without a degree.

[@anhthihoang2200]

Thanks Khan Academy for making my life easier.

[@allchiewfc]

You are way too much awesome than my lecturers. thanks for the video and the straight forward explanation!!! =)

[@nabamitamitra001]

thank god ppl like u exist!

[@nicholasaddisi2822]

U are just the best. U must be awarded for that

[@toffeecheung]

you just used 10 min to explain something I've been struggling with for the past few weeks...

[@wtfizzjus]

Makes sense, they're too busy disliking these videos instead of teaching properly

[@panmaru101]

DR. Khan!!! Thank you I wish i could repay you for doing what my Ochem professor couldn't...teach.

[@Idropfatklds]

can you do more complex molecules like chiral centers of cholestrol ?

[@OnthLvRoad]

No it's because the mirror image from the original molecule is superimposable ! Look at the molecules, they are the same molecule ! You are not obliged to do the mirror and redraw the molecule, as you can see, you can do a vertical line from CH2 (on the top) to the bond CH2 ----- CH2 on the bottom, what means that the molecule isn't chiral ! :)

[@lounismohamed1234]

ooh man , u're awesome , I can understand everything now, thumbs up

[@jasonwinker9569]

Thank you so much! This helped alot with my chem class! you rock!

[@rkpetry]

But in the 2nd molecule the H's could be cis or trans, and the F's alternate likewise,--so it's indeterminate chiral depending on the H-F chirality...

[@jamaluddin9158]

Raymond K Petry yeah the last example needs clarification

[@moooooooooooooooooo2]

the BEST orgo videos ever... wow.

[@lilaclilac1907]

This really helped! Thank you!

[@curtpiazza1688]

Great! Thanx!

[@morderon4]

One problem with the difluoro cyclopntane compond: it has Z and E izomers and can be Chiral

[@dt02909]

Please make sure to clarify when mentioning molecules that contain Chiral Carbons but is still a, Achiral molecule. Most of the time molecules that contain chiral carbons are indeed chiral molecules. This can be confusing to people who are new to the Chirality.

[@girlsgotlove]

You're a genius.

[@nadiaballard9160]

the 1,3-difluorocyclopentane...could you not bisect it from C-2 down for an axis of symmetry?

[@MsDody94]

-If I flip the molcule of the 1st example 180 degree I think it will fit on its mirror-image. -In the last example, The vertical line passing exactly the middle of the ring, isn't it a line of symmetry???? What am I missing? :(

[@auggie137]

MsDody94 that's what I was thinking. Isn't it symmetrical

[@ihofaerefa]

The difference between 4 different groups and the last molecule having two chiral carbons is confusing...

[@philly1076]

i agree, i didn't get it

[@Ronaldo9633]

Wow ideed he is something else. And the program he uses is pretty cool too. Does anyone knows the program's name?

[@toffeecheung]

Thank you!! THANK YOUUU

[@DrMatsy]

The DiFluoroCyclopentane is only not chiral if both Fs are going in the same direction. If you have one going into the plane of the page, and one coming out, then the molecule chiral isn't it?

[@hannah1362]

Helps a lot

[@jankichaudhari6590]

thanks a lot.................really helpful

[@Ibahz]

good job on the vid, dr. khan

[@Ibahz]

good job on the vid, dr. khan, but I have a question- what role does the fluorine play in determining chirality at 7:20

[@OnthLvRoad]

good question, i want the answer too please !!

[@redhotpilgrim]

so then is saying that a particular carbon is chiral designating it as a stereocenter? are these nearly interchangable terms when referring to a single carbon?

[@shadenyakoub671]

when do you know to stop your "walk" around the cycle? because if you continue until the end, the molecule would not be chiral.

[@03raq]

did you understand which ones where the 4 different groups on the last example? Hydrogen, Fluoride and what are the other 2?

[@ahmed281094]

Thank you

[@aghebs3372]

amazing so helpful!

[@stku92]

If you have individual chiral centres in a molecule, would the whole molecule be chiral?

[@TheDevarchan]

Which video,comes in logical sequence,to this one..?

[@georgieacero7043]

Would the 1,3 Diflourocyclopentane at the end of the video be a meso compound since it has an inner line of symmetry if you draw a vertical line through the middle of the compound? Thanks in advance!

[@Sorriyabanadouri]

Georgie Acero yes

[@giuseppe-sabra]

probably all of our orgo chem teachers

[@kevincaldwell4112]

Does the axis of symmetry have to go through the chiral centre?

[@sarasherman2662]

How do double bonds affect a chiral center? Does it make that center carbon achiral?

[@MrKcl1]

what if you had salbutamol? how can we figure out the chiral carbon there??

[@03raq]

I didn't really get in the last examples which are the 4 different groups connected to the C So we have C is connected to H, F and? what are the other 2 groups?

[@stku92]

Nevermind. :)

[@qlossyvrz1599]

I have a question, how is the last example not chiral? is it because the example has two chiral carbons?

[@yuleruiz483]

when you have a double bond does that count as the same atom?

[@laava1028]

uhh whut?

[@kaliakoirmodelhighschool4190]

CH3-CH2-CH=CH2 Is this a chiral compound?

[@Sorriyabanadouri]

Kaliakoir Model High School no there are no chiral centers

[@JL0419ful]

is 1-bromo-1methylcyclohexane chiral?

[@thisisnotmyfinalform7856]

JL0419ful no its not

[@emilypaille8704]

Proof that not all heros wear capes

[@jsphamoabeng]

can u have a chiral center carbon in an achiral molecule?

[@jsphamoabeng]

never mind, got my answer from the last seconds

[@supaahflyy]

Joe Amoabeng Not sure if im right but i think it is termed a meso compound when there are chiral centres, but the whole molecule is not chiral (Diasteromer i believe?)

[@JoblessNunnu]

yes chirality and chiral centres are not related.........to optical activity a sp3 molecule with 4 diff. groups attached 2 it is a chiral centre....all single carbon mol. having 4 diff. groups attached 2 it are optically active....expect teritary ammine whereas as chirality is a necessary amd sufficient condition 4 a compound to be optically active.......... 1) a molecule with non superimposable mirror image is having chirality..... 2) if a molecule can't be divided in2 2 eql prts it has chirality a molecule is chiral if it follows the above conditions even if it has chiral centre or not,...,,,,,,so both molecules having chiral center and not having chiral centre obeying 2 rules possess optical activity

[@JoblessNunnu]

also in a achiral molecule there may or may not be chiral centre....hope understood😊😈😂😤

[@MonkeyDLuffy-xr4fl]

Yep, it's called a mesocompound

[@nihayaturrohmah4230]

#20

[@foeasy16]

@TsuruCrane no its not lol...its pronounced "Kiral"

[@ericterry4544]

How is that a butyl group when there are 4 carbons?

[@avitalsimone879]

+Eric Terry look up butyl...the prefix but- is for 4

[@avitalsimone879]

+Avital Simone its an alkyl group with 4 carbons...but + yl = butyl

[@ericterry4544]

+Avital Simone My bad. I was thinking butyl meant three for some reason (lol).

[@MonkeyDLuffy-xr4fl]

Ily

[@Sakuyushi]

the last example made me like "OH SHIT I GOT IT!"

[@Riceater88]

If everyone had a master's degree, what then would set you apart from your peers in a job interview. College isn't as much about learning as it is setting yourself apart from the competition. A degree from Khan Academy and other online courses will essentially be laughed at in a professional setting. It's nice for furthering your own education but as a degree or serious alternative to college? No, sorry..

[@batmanish]

no it isn't chiral

[@SSZero88]

Death Stranding brought me here

[@therealhotchocolate]

@Ronaldo9633 like yahoo doodlepad

[@wingl5841]

Just repeat butyl 3 times while you slowly write it. Not annoying at all...

[@lucianoval903]

Should make shorter videos!