Nucleophilicity vs. Basicity

[@SageWillow]

thank you for making this concept so easy to understand. my ochem professor spent 20 mins humiliating our whole class and dismissed us early because according to him we are unteachable and too stupid to understand this concept -

[@aravjee8982]

that's sad

[@videochris69]

the colors and succinct repetition, as well as willing to erase work and start again... everything about the videos fosters learning of a good attitude and increases knowledge from memory.... love the format and thanks KhanAcademy

[@marloon5]

free education... something the government should provide.. khan academy, freelanceteach, wolfram etc. I consider them my government :D

[@14aravindlochaner24]

Marlon Lingner collegepedia... My favourite..

[@y2jrajat]

M. Lin search nptel channel. It might interest you.

[@feudal_age_spearman_with_i9410]

Key point: "Nucleophilicity is how good it is at reacting. Basicity is how good is the bond that is formed"

[@megamaje]

You really should get a nobel prize for what you've done for education.

[@BullsRock32]

my teacher went over 5 chapters of orgo in 3 lectures. i had no idea what was going on in class. Thanks to you, I have a shot of getting an A in Orgo!!!

[@fleshcookie]

Such a brilliant mind, it is a privilege to listen to Sal lecture. There are students paying thousands of dollars at prestigious schools for a single Ochem course who are not getting the caliber of lecturing that Sal delivers. In ten years the Khan Academy will be a household name.

[@pranjaltiwari7502]

fleshcookie ...we are half way here now😀

[@shyaamaldwivedi9640]

we are all the way here now

[@PepsiGurl93]

So true! I've heard Stanford School of Medicine(the Stanford!) found out about Khan and are looking to change their med school curriculum. They realize you can teach the student in 10x less the time and allow them to do more hands on activities. Hopefully, our undergrads will figure this out soon lol

[@Repossession01]

The curly arrows show the movement of electron pairs, not single electrons. And Lewis bases are defined as electron PAIR donors. There's a fundamental difference!

[@87colleen]

It finally makes sense, makes studying for the MCAT much easier. Thanks!

[@swtllbabyangel]

I wish you are my teacher, I think I learn more on here than in lecture. Please post more! I like the way you break down to babysteps.

[@ahmadghazwi]

Thanx for all the help you give i learned in the last 10 mins much more than 50 min class with my poor doctor

[@Ivana9910]

basicity is a molecule's property. nucleophility is the context of a reaction, and it varies by situation. basicity is only a factor to nucleophilicity.

[@DrP3natrator]

After reading chapter7 (substitution RXN's) I had questions, and you went over each of them. GOD BLESS!!

[@captainabhious]

You should write the next edition of everyone's Ochem textbook.

[@FaerieDust]

I love when Sal says "Now let's imagine...", because I know I'm about to have an epiphany!

[@jessicaJovel]

wow this is a dense video! thank you for taking the time.

[@daras07]

Good that you talked about the sterics :)

[@sweeetmelody9]

Wish I found this earlier! Thanks for the help!

[@sameerkhnl1]

very helpful. Thank you very much

[@vishwajeet626]

You rule sir!! I think you will become the most famous teacher on U tube very soon!!!

[@aze77]

thank you this helped a lot

[@josieleger6088]

this is a great video! thank you so much!

[@singing.winnie]

nucleophilicity and basicity.. so freaking confusing.. 😂😂

[@Alxphat]

good teaching!!!

[@BRENNANSTECHBITE]

You're amazing, thank you!

[@e0f3z]

thank you..

[@norwayte]

Thank you. Keep on going.

[@aaravnautiyal9088]

What will happen if we add the concept of aprotic n protic in the basicity?

[@teeheehaahaaho]

thank you! you are amazinggggg

[@sidewaysfcs0718]

similar to how in the halogen group, acid strength increases downwards, but electronegativity increases upwards

[@curtpiazza1688]

Thanx again ! 🎉 😅

[@fleshcookie]

Thats interesting Sal has actually done some videos with stanford medical school staff! (see healthcare and medicine for these)

[@wimpy1371]

Thanks

[@omeryugenkorat8783]

Why is iodine a weak base if it is very polarizable? In the last video you said that the polarizibility of iodine happens because it's outermost electrons are relatively loosely tied to the nucleus. So doesn't it make it a good electron donor that's likely to react?

[@bonbonpony]

Iodine is neutral, so I presume that you meant the iodide ion. Then it is a poor base, being a conjugate base of a strong acid, HI (the hydroiodic acid). So the question really is why is it a weak conjugate base, because that's why makes its conjugate acid (HI) so strong. Acid strength is about the tendency to give away a proton, and this is possible only when the conjugate base is weak (i.e. more stable than its conjugate acid), because otherwise it would rather want that proton back instead of giving it away, and the reaction would shift toward HI instead of dissociating and giving the proton to someone else. So why is iodide still "happy enough" without its proton so that it doesn't want it back? Because the iodide ion is large. Its nucleus is surrounded by a lot of electrons which shield each other from the nucleus, so one electron that way or another won't make much difference - it's just a drop in the sea. This extra electron could be distributed over a larger volume (hint hint: smaller charge density), which lets the iodide accommodate this negative charge better than other, smaller ions. This electron is also farther from the nucleus, so it feels its influence less, being shielded from it by other electrons.

[@VijayaLakshmi-wq3bc]

Amazing job sir

[@MrChemusic]

amazing!thank you!!!!!!!!!!!!111

[@32saurabhhireiv-1reg8]

Sir,But the Flourine will have strongest Conjugate Acid(HCL) So,It should be Less Basic Than Iodine?

[@OutstandinMediocracy]

I just started loading like 10 of khans videos. its going to be a busy night

[@sanjaych5501]

How to compare nucleophilic order betwwen 1.CH3-O^- 2.CH3-CH2-O^- 3.CH3-S^- IN CH3OH

[@E4B088]

3>1>2

[@thecleener]

this vid is so boss

[@johnstillman2935]

Khan your an awesome individual more intelligent yhan I could dream of being but I have one question , forgive but i have a question , is diphrentiate the same as differentiate . Forgive me the sarcasm but I am german .

[@kuntarinirahsilawati920]

Very good explanation. Now I understand.

[@shaghayeghjoojoo]

what about neutral or +vely charged nucleophile? and how the solvent effects the nucleophilicity?

[@bonbonpony]

Neutral nucleophiles are weak. They can still make use of their extra lone pairs of electrons, but instead of directly attacking other molecules all by themselves, they have to wait for a good opportunity to do so. They can't kick off the leaving group, they can only wait until it gets kicked off by the solvent, leaving behind a positively charged carbocation that attracts them strongly enough. I.e. they need a partner who is stronger and more attractive than them, because they won't make the move on their own ;) I never heard of positively charged nucleophiles though. Having a positive charge, it would be even harder for them to react with other positively charged atoms (electrophiles).

[@kal3idosc0pe]

the guy that disliked this video, got an F on his orgo exam

[@مِسكيم]

😂😂

[@MrBlash93]

Thank you 4 ur video

[@patrickasinger2681]

Can someone give a brief explanation as to why hydroxide is more nucleophilic than fluoride in a protic solvent? I get that iodide has a large electron cloud and all that but I can't see what causes the hydroxide to be more nucleophilic than fluoride.

[@michaelpaterson8938]

Fluorine is more electronegative than oxygen, so is less 'inclined' to lose the electron from its anion...

[@beingfor1825]

+Patrick Asinger As sal said that nucleophilicity is a kinetic concept means how fast does it react or how good it is at reacting? fluoride being more electronegative can accommodate the negative charge and is not good at reacting. on the other hand, oxygen is less electronegative than fluorine, it wants to react as fast as possible to get rid of the extra electron density and hence oh is more nucleophilic. Even though OH is surrounded by hydrogen atoms of the other molecules but still they are not capable of balancing the negative charge of oxygen.

[@aditiapoorva6117]

Hi

[@aditiapoorva6117]

Patrick Asinger hi

[@oom3573]

@@beingfor1825 you are right.. And another reason is the size of OH- is the smallest among the all other anions ..so naturally it has the highest mobility among them. Therefore it can easily transfer/donate it's charge to other cation.. At a faster rate. So as thia is a kinetic phenomena which is depends on the speed of the ions it acts like this

[@jorge.04]

wait why is F- more basic than I-? Isn't I- less electronegative and thus more likely do donate electrons?

[@Oldmanfnaf]

+Jorge A. I is more acidity than F. because of the acid trends.left to right and up to down

[@taniamukherjee8590]

This is confusing because you are looking at two opposing trends here: electronegativity versus bond strength. While F is more electronegative and should make sense that it would be a poorer electron donor, ultimately bond strength and anion stability are the more important factors that affect basicity. Firstly, we know that bond strength decreases as we go down the group. Thus, H-F is a shorter and stronger bond than H-I. Therefore, it is more likely to stay in the HF form and not the F- form, with the reverse being true of HI and I (I- is present in solution in significantly greater amounts). Thus, from another perspective we see that F- has served a better role of being a better "electron donor" by being preferentially present as HF than in the case of I- (where HI rarely exists in solution as HI is a very strong acid and almost instantaneously dissociates to form I-). If you look at the F- anion, it is very small compared to I- and thus the extra charge is spread over a tiny atomic radius (compared to other halides, most appreciably I-) and is very energetically unfavorable. Thus, it is less likely to exist in the F- form and seeks out a positive charge to liberate its extra electron. The I- is able to hold this negative charge much better with its larger atomic radius. Hope this makes sense? This was honestly super tricky for me too when I started out.

[@rohitbiswakarma5298]

HI is a very strong acid

[@ayushanand5221]

@@rohitbiswakarma5298 The HF is the most acidic among the halogens

[@CH-dq1oi]

@@ayushanand5221 no in Terms of Hydrogen Halides the one with the bigger Ionic radius is the stronger acid HI>HBr>HCl>HF

[@imaMickeysman]

12:20

[@vinayaktawade146]

please make sound more clear

[@dr.nirmalsingh3989]

Not explained well

[@user-fx8th4yv3j]

14yrs????!!!

[@caesar619]

1 person still doesn't get it

[@nihayaturrohmah4230]

#33

[@JusGoAhead]

i just want to know like... which basicity is stronger between phenylamine, methyamine, ethylamine, ammonia cuz i get hard time to rmb this... ....

[@bonbonpony]

Comparing the atoms alone won't tell you much, because they're all the same (neutral nitrogens). But in one of the molecules, you have an aromatic ring which can resonate with the lone pair on the nitrogen, and resonance stabilizes the entire molecule, making it less reactive (i.e. weak base). Other three molecules differ only by the length of the carbon chain. No resonance is available for them, so what you consider next is the inductive effects. Carbon chains are electron-donating, so the longer the chain, the more stable the molecule is, i.e. less basic.

[@edthoreum7625]

not good for 1/2 blind people,,,please bigger visuals?

[@bonbonpony]

It's easier for you to buy a bigger screen than for everyone else to bend to your needs, just saying :q

[@09nabila]

@Systice4 ahahahahahahaha! thanks, i needed a laugh! :)

[@salshammas8856]

Lol do u study this off wikipedia or something? Relate it to Organic chemistry please. Basicity is related to stability as opposed to nucleophilicity which is reactive..