00:01
All right, we're looking at lysine here, which i've drilled the structure, and then we have a pca associated with each of these places where layball proton is going to be, and we're wondering what this is going to be a ph 1 .3.
00:14
And so i'm going to associate a pca with each of these spots.
00:22
So the carboxylac acid is going to be the most acidic.
00:26
And then all these amine groups, the one closer to the oxygen is going to be more acidic than the one farther away.
00:33
Right, piece oxygen, this isn't having an electronist drilling effect, stabilizing this and making it more acidic.
00:41
And so we can kind of consider this with three label proton spots, a tripodic acid.
00:48
And so we're going to start low ph and we're going to go up to high ph.
00:53
And so at low ph, we're starting down 1.
00:56
When we're adding base, we're going to start going up.
00:58
And i'm not labeling anything just said.
00:59
I'm just going to draw the headline here.
01:01
We're going to start going up a little bit, and then we're going to go up steeply.
01:04
At the first equivalence point.
01:07
Can i go up steadily, then go up again at the second one, kind of go up steadily, go up again, and then level off by the end of it.
01:21
So what is happening at each of this point? so all the way down at ph 1, that's below every p .k here.
01:27
So everything would be protonated in this state.
01:31
This would be nh3 plus.
01:34
This would be nh3 plus as well.
01:39
So with everything protonated, we have a very acidic molecule.
01:42
So i'm going to label this point a.
01:48
Er.
01:50
Yeah, i'm trying to figure out how to squeeze this all in here.
01:53
I made the graph too big.
01:57
Point a looks like that.
02:03
I don't really want to dry it completely all the time.
02:06
I'm going to change this with each point.
02:08
So all the way at point a, this is what it looks like.
02:11
All right, everything is pronated and we have two positive charges here.
02:17
So we start adding base.
02:18
And what happens here is we hit the center of our barfair point right here.
02:23
I'll call this point b.
02:25
In the center of our barfair point, we've turned half of one.
02:30
We're in look at this carboxic acid here, right? because it's most acidic.
02:33
We've converted half of this into our carboxylate form.
02:37
And that happens at the one -half equivalent point.
02:41
And so what that looks like is we lose.
02:43
That h there and we pick up a negative charge.
02:49
So that's what happens at the half equivalence point.
02:53
So this is the current state of molecule.
02:56
We keep at and base, adding base, out and base, and we just then hit this just start sharp increase and right in the middle that sharp increase is going to be the first equivalence point.
03:08
In that point c, in that point c we've now completely disassociated everything.
03:15
So at point b, this was half and half this and the protonated form, a point c is 100 % this.
03:25
So point b, 50, 50, this, and the one with the h on it, and point c is 100 % this.
03:35
So that's kind of where we're at.
03:39
So we keep adding base, adding base, and then we get here at another half equivalent's point, 1 .5, equivalence points with d.
03:47
What we started doing is now we've started deprotonating this second, this first domain group rather...