Nucleophilicity vs. Basicity 

that's sad

Marlon Lingner collegepedia... My favourite..

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

fleshcookie ...we are half way here now😀

we are all the way here now

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.

😂😂

I think the size of iodine ion is very big in size so it's lone pair gets scattered and therefore not available easily to donate but thats ,thats not the case with flouride..(comparatively speaking)

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).

3>1>2

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

+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.

Hi

Patrick Asinger hi

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

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.

HI is a very strong acid

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

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

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.

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