"For to him who has will more be given, and he will have abundance; but from him who has not, even what he has will be taken away" (Matthew 13,12 RSV).
Hello dear sir, the video after this one is titled as "private video", how can I watch it? please guide because I'm watching all the videos of your organic chemistry course in series and don't want to miss any. thank you!
@herpderpmonkey It's not about the bromine attaching itself, it's about the carbocation forming in the first place. If the molecule "feels" that the carbocation will not be stable, it doesn't form. The inductive effect of the CH2 groups lowers the energy difference between normal and carbocation states and thus encourages the molecule to lose the electron. The amount of negative charge pushed onto the carbon is not enough to blind bromine from seeing that positive charge though.
That rule would be explained just by inductive effect no ? I mean if you drew arrows explaining that on the molecule it'd be way more intuitive i think (with +I effect caused by 3carbon chain on the right & slightly delocating electrons on alkene).
(hopefully someone reads this) Does anyone know why the next few videos on the playlist are listed as private & whether you're missing out by missing those videos? Thanks :)
You should mention that the carbocations are stabilised by sigma conjugation which is the orthogonal overlap between the empty p orbital on the carbocations and a neighbouring carbon atom with electrons in filled CH sigma orbitals. The more carbons around it hence the more stabilisation interactions and so te tertiary is the most stable. Also there no talk of methyl cation species which are the least stable. It is expected that people discussing markovnikov rules would need the information up the level I have stated.
@n1a1s1i1m A year later.. Its not bonded to a Cl, the point is that the H goes to the place where MOST of the H are bonded. The C-HH to make C-HHH. Or you can look at the carbons and see which one has the higher carbocation (In this case, it was secondary). We know carbon can have tertiary, secondary, and primary. In this example there is no tertiary so look at the secondary one.
Well after some research i think i need to apologize. Apparently it's an exclusion... (Or more precisely it's a rule that names don't have to follow spelling rules xD) It is actually Markovnikov after all.
Quick question Sal (or anyone else): should Sal not draw a single arrowhead instead of ----> because ---> implies that there are two electrons being lost from an atom but in this mechanism we are seeing only one electron at a time being moved from one atom to anotehr. Anyone want to clarify this? thanks.
@n1a1s1i1m I believe the left one works because it has two carbon groups to stabilize the positively charged transition state whereas the one on the right doesn't work as well because it only has one carbon group. This means that the one on the left has a lower energy hurdle to jump over so it is more likely to occur. I'm not sure if that is what you mean? Either way, your post is a year old so you probably don't even care anymore.
very nice videos...salute to khan academy....one question please : why the slightly positive hydrogen in HBR is attracted to the double bond precisely , why it is not attracted to any other single bond? ....thx
Because at the double there is an electron rich site, caused by the presence of the π electrons, since the partial hydrogen is an electrophile it will be attracted to it. The single bonds have no charge
I have a question regarding methyl shifts. If you have a larger group (say CH2(CH3)2) would it be possible for this group to shift? Say it would turn a secondary carbocation into a tertiary carbocation.
At 8:45 he says that secondary carbocation is more stable as it can borrow electrons from the electron rich molecules but since the electronegativity difference between carbons is 0,how can the secondary carbocation borrow electrons ??please someone help..
So it's possible that we get 1-bromopropane, but more unlikely? In book I was reading it said that it's not possible to produce 1-bromopropane like that.
Sarah M.T. It's saying that since the secondary carbocation is more stable, in a reaction, it will form the bond with Br much more often than the reaction where the primary carbocation bonds with the Br.
@herpderpmonkey Not only that, but imagine: when the molecule takes the hydrogen, is it going to go for it from a carbon with an overall charge of 0 (neutral) or a carbon, let's say, with an overall charge of -0.01?
Hi Mr Khan Can I please have the link for the private video. I Am busy with the whole series and would like to watch and make notes on all your Organic chemistry videos. Its video number 29.
hi I would like to ask....Would the hydrogen still be attracted to the carbon with more hydrogen , if the ' group' was not the electron donating propane group but instead an electric withdrawing Halide ion? Would then change the stability of the carbocation right? Thereby affecting where the hydrogen bond first ? thanks in advance to anyone T.T
+Lai Jing Wei It would still be attracted to the carbon with more hydrogen atoms. It doesn't matter whether it's a halide or a carbon chain--the main thing is that the carbon can 'borrow' negative charge off of those groups to stabilize its positive charge.
you got it all wrong, after the arrangements of the Hydrogen and Halogen, there are no more double bonds in the product. Try and rewatch the video and you see what happens to each segment at the electron sharing and bond breaking. Its tough but you can do it! Also, watch the case-sensitive when spelling out elements/compounds!
Are these really comments from a decade ago???? Wow Im here frustrated inhave to do this for the rest of my school years, dont know why i chose this course but oh well. This was helpful though
I love you, Khan. I am AA, in y11 just starting Oc @side, have heaps of hw, will see this again when im done from this shit, wgm in a few months, i wonder who itll be, i can't wait, imglhsm
Skip to 5:45 for the Markovnikov's Rule explanation.
Thanks
thank dude
Not all heroes wear capes
Interestingly enough, some wear thongs.
thanks
Funny looking at comments from 6 years ago and suffering from the same things these people did.
1 year later from you i am also moving with same phase
Well,4 years after you nd here i am,Dealing with the same thing
Thanks, Bro- mopentane
I'm running out of words tanking you, please give this man a Nobel prize!!!!!!!! BEST TEACHER EVER
"For to him who has will more be given, and he will have abundance; but from him who has not, even what he has will be taken away"
(Matthew 13,12 RSV).
Praise God you summed it up in a verse…Jesus is a,ways the answer!
the hydrogens.....(starts drawing it)...thee hyyyydrogens (continues to draw it)
lmao im dying over here.
Your great man, thank you for simplifying and helping me understand chemistry.
Hey what are you doing now 9 years later
WOW I GENUINELY UNDERSTAND THIS NOW. Thank you so much!
this man and doctor stone are really amazing teachers
Dr stone is my go to exam time entertainment
I always applaud at the end, brilliant!
I might just skip all my classes and just watch these videos!
Thanks so much! I don't know what I would do without these videos! They are very helpful .
You explained it very clearly,I got it,even I'm not much familiar with organic chemistry,thanks a lot!
"the rich get richer"
+oliviaanna42 *Bulls on Parade plays in the background*
Hello dear sir, the video after this one is titled as "private video", how can I watch it? please guide because I'm watching all the videos of your organic chemistry course in series and don't want to miss any. thank you!
whatever i learnt from this video...i havent learnt that in one whole year!!!! hats off to this man
Beautiful explanation..u guys make things so easy... :)
@herpderpmonkey It's not about the bromine attaching itself, it's about the carbocation forming in the first place. If the molecule "feels" that the carbocation will not be stable, it doesn't form. The inductive effect of the CH2 groups lowers the energy difference between normal and carbocation states and thus encourages the molecule to lose the electron. The amount of negative charge pushed onto the carbon is not enough to blind bromine from seeing that positive charge though.
NOW I get it !! Thanx so much! 😊
if my uni professor was half as good as you, I wouldn't be watching this while crying before my finals.
Daylily Chen . Relatable
THANK YOU
Sal, I am addicted to these videos.
Amazing vid. All organic teachers should assign this video.
Thank you so much for the visual explanations
best voice ever! Lovely!
Awesome it really helped me. I never used to get why the carbocation get more stable with more carbons naw i do. Thank you very much
The actual reason for Markovnikov's rule is hyperconjugation of alpha-hydrogens.
Have no idea what that means lol
Same no idea what he said
Thanks for helping me!
That rule would be explained just by inductive effect no ? I mean if you drew arrows explaining that on the molecule it'd be way more intuitive i think (with +I effect caused by 3carbon chain on the right & slightly delocating electrons on alkene).
It can also be explained by the relative stability of a carbocation.
(hopefully someone reads this) Does anyone know why the next few videos on the playlist are listed as private & whether you're missing out by missing those videos? Thanks :)
I nearly feel like dropping out, then watch your videos and think 'ah its not so bad ill stick around a tad longer'!
You should mention that the carbocations are stabilised by sigma conjugation which is the orthogonal overlap between the empty p orbital on the carbocations and a neighbouring carbon atom with electrons in filled CH sigma orbitals. The more carbons around it hence the more stabilisation interactions and so te tertiary is the most stable. Also there no talk of methyl cation species which are the least stable. It is expected that people discussing markovnikov rules would need the information up the level I have stated.
@n1a1s1i1m A year later..
Its not bonded to a Cl, the point is that the H goes to the place where MOST of the H are bonded. The C-HH to make C-HHH.
Or you can look at the carbons and see which one has the higher carbocation (In this case, it was secondary). We know carbon can have tertiary, secondary, and primary. In this example there is no tertiary so look at the secondary one.
OMG it has been ten years, and nowadays no know can teach better than khan academy
Hey, it's rly outdated but Morkovnikov goes with "o" :)
And yes i speak Russian so i do know:)
Well after some research i think i need to apologize. Apparently it's an exclusion... (Or more precisely it's a rule that names don't have to follow spelling rules xD) It is actually Markovnikov after all.
You could have just edited your original comment but NO...
gotta respect his choice. not many people would choose this way these days :D
Thanks 👍
Quick question Sal (or anyone else): should Sal not draw a single arrowhead instead of ----> because ---> implies that there are two electrons being lost from an atom but in this mechanism we are seeing only one electron at a time being moved from one atom to anotehr. Anyone want to clarify this? thanks.
@n1a1s1i1m I believe the left one works because it has two carbon groups to stabilize the positively charged transition state whereas the one on the right doesn't work as well because it only has one carbon group. This means that the one on the left has a lower energy hurdle to jump over so it is more likely to occur.
I'm not sure if that is what you mean? Either way, your post is a year old so you probably don't even care anymore.
Amazing! Thanks sir!!
Thank you very much just what I needed
I LOVE YOU !!!! Thank you !!
Thank you so much!
I see the light.
Awesome! Thanks
this dude shud be man of the year
I feel like my brains about to explode
very nice videos...salute to khan academy....one question please : why the slightly positive hydrogen in HBR is attracted to the double bond precisely , why it is not attracted to any other single bond? ....thx
Because at the double there is an electron rich site, caused by the presence of the π electrons, since the partial hydrogen is an electrophile it will be attracted to it. The single bonds have no charge
Johanna Sky thank you very much for the reply...things are more clear now
I have a question regarding methyl shifts. If you have a larger group (say CH2(CH3)2) would it be possible for this group to shift? Say it would turn a secondary carbocation into a tertiary carbocation.
OnlyNeedJuan Gaming no only hydrogen and methyl groups can shift
can you use bond line structure on this video, please
awesome! :)
i hope they have this for orgo ii
Thank you very much wallah u r bro ❤❤🙏
Genial señor, thanks
is dule to inductive affect caused in secondry carbon
At 8:45 he says that secondary carbocation is more stable as it can borrow electrons from the electron rich molecules but since the electronegativity difference between carbons is 0,how can the secondary carbocation borrow electrons ??please someone help..
So it's possible that we get 1-bromopropane, but more unlikely? In book I was reading it said that it's not possible to produce 1-bromopropane like that.
Thanks!
is it always the case that the most stable carbo cation will also have one of the carbons with the most Hydrogens acquiring the other hydrogen?
Thanks Sal
Watching in Octobers LAST WEEK 😂😂😂😂 After 10 years 😂😂
Couldn't you make the argument that because of sterics the bromine would want to attach to the first carbon?
you are really great
thanks !!
so what if the secondary carbon is more stable? doesn't that mean it is less likely to react with other things? why is that needed?!
ikr?!
Sarah M.T. It's saying that since the secondary carbocation is more stable, in a reaction, it will form the bond with Br much more often than the reaction where the primary carbocation bonds with the Br.
@Kash Army what about endothermic reactions
THANK YOU
"Borrow electrons from some of its friends" HAHAHAHA
@herpderpmonkey Not only that, but imagine: when the molecule takes the hydrogen, is it going to go for it from a carbon with an overall charge of 0 (neutral) or a carbon, let's say, with an overall charge of -0.01?
I love you khan academy
Hi Mr Khan
Can I please have the link for the private video. I Am busy with the whole series and would like to watch and make notes on all your Organic chemistry videos. Its video number 29.
Gracias.
you are amazing :)
those rerepepetitions are kikikilling me.lol
thank youu
what vid is before this?
which video is the previous video?
I know I'm like a year late.. But go to the reaction mechanism playlist and you'll know :P :)
So, what I can see here is that the more stable the carbocation, the more it tendency to be bonded with H+, am I right? :\
helpful
hi I would like to ask....Would the hydrogen still be attracted to the carbon with more hydrogen , if the ' group' was not the electron donating propane group but instead an electric withdrawing Halide ion? Would then change the stability of the carbocation right? Thereby affecting where the hydrogen bond first ? thanks in advance to anyone T.T
+Lai Jing Wei It would still be attracted to the carbon with more hydrogen atoms. It doesn't matter whether it's a halide or a carbon chain--the main thing is that the carbon can 'borrow' negative charge off of those groups to stabilize its positive charge.
@O0oSorousho0O Yes, when the valence shell is filled.
you got it all wrong, after the arrangements of the Hydrogen and Halogen, there are no more double bonds in the product. Try and rewatch the video and you see what happens to each segment at the electron sharing and bond breaking. Its tough but you can do it! Also, watch the case-sensitive when spelling out elements/compounds!
so simple coz of u
ty
Wait why is it that he draws the arrow from one carbon and attached the hydrogen to the other carbon? Can someone explain?
markovnikov's rule starts at 5:50
yea "TANK" him a lot
Are these really comments from a decade ago????
Wow
Im here frustrated inhave to do this for the rest of my school years, dont know why i chose this course but oh well.
This was helpful though
Wouldn't they be constitutional isomers?
Markovnikov Rules
I love you even more. I'm Indian too btw xD
cool
sory but what's the product
ch3ch(ch3)ch=ch3 + hbr
Shouldn't you have explained it with hyperconjugation and the number of alpha -H..
I love you, Khan. I am AA, in y11 just starting Oc @side, have heaps of hw, will see this again when im done from this shit, wgm in a few months, i wonder who itll be, i can't wait, imglhsm
swiper no swiping
OHHHH MANNNN!!! (runs away).
I love you
WTF is hbr? dude if you mean hydrogen bromide you need to use a capital for the first letter in the element to be able to distinguish...
#27
👏👏👏👏👏👏👏❤️❤️❤️❤️❤️
thanks sir