00:01
Okay, so in problem 18, you're asked to rank these nucleophiles in terms of, which is the best.
00:08
So what makes a good nucleophile? first, a negatively charged nucleophile is going to be better than an uncharged one.
00:19
Oops.
00:22
So, oh, h minus, is going to be better than water.
00:27
Lower electronegativity, the higher the nucleophilicity.
00:32
So if it has a lower electronegativity, so if it has a lower electronegativity, so if it's, if you if it's more to the left of the periodic table, it's going to be a better nucleophile.
00:51
If it's less reactive in a polar product solvement, it's going to be a good nucleophile, which it means it will have a oh bonding or in age bonding.
01:28
And if it is more bulky, meaning that it has bulky substituents, it's going to be a worse nucleophile and a better base.
01:52
Okay, so now that we've got those rules out of the way, let's look at the examples.
01:58
So in part a, you need to rank water, hydroxide ion, and nh2 minus.
02:19
So the negative charge is going to be better than a neutral charge.
02:24
So the weakest one that we're going to have is water, just based off the first rule.
02:30
Now comparing oh and nh2 minus, the nh.
02:36
H2 minus is going to be a better nucleophile.
02:43
And i'm going to show a nucleophile as in u minus.
02:47
And this is because n is to the left of oxygen in the periodic table, meaning that it's going to be a better base and to be a better nucleophile because nucleophilicity increases as basicity increases.
02:59
So ranking these in order, it's going to be water, hydroxide, and nh2 is the strongest.
03:12
And part b, we need to rank f minus, oh, h, and br minus.
03:32
So all of these have a negative charge, so they all pass that test.
03:35
They're all good, okay, nucleophiles at least...