00:02
So this question is about the diaprotic acid.
00:09
So first of all, what we have right here is that you have this acid, then you're going to ionize stepwise.
00:21
This is the first step.
00:24
So you have this.
00:31
So that is the k -a.
00:33
Okay, this is the k -a -1.
00:35
So this equation corresponds to the k -a -1.
00:38
Then next step is this.
00:46
So that's represent k -a -2.
00:48
So if you put all that together, so this is equation 1 and 2.
00:54
So 1 plus 2 will give this.
01:06
So that will be the k -a -1 multiplied k -a -2.
01:12
So in general, if you add two reactions together, that the equilibrium constant will be the multiple both.
01:24
So that is the one.
01:26
That is the first part.
01:29
And the second part right here is that determine the ph.
01:33
Determine the ph of this.
01:36
Well, the second part of the question is trying to see which one will have a higher concentration.
01:44
Of course, because the weak acid, so this one will have much.
01:48
Higher concentration.
01:51
And next one will be hydronia ions, that will be a little bit higher, compared to the concentration of this.
02:03
So remember, this should be very close.
02:06
Okay, their concentration should be very close.
02:08
And the low, the one that has low list concentration is this.
02:17
The next question is, the, the next question is, determine the ph.
02:22
So in general, for this diaprotinic acid, and we can just treat as monoprotic acid, so the hydronia concentration will be the total concentration in these cubes, k -a -1.
02:42
So the concentration right here is, well, the c is the concentration, total concentration, of the acid, okay? so it will be 0 .0 .1 .0 .0 .0 .0.
03:01
And right here is k .a .1.
03:03
We're going to only use ka1, because we're going to treat this as a monopronic acid.
03:11
So that would be this.
03:14
That gives you 2 .45 times 10 to the power of negative 3m.
03:22
So the ph, well, that's the concentration of protons.
03:44
So this is the easy way, okay? so what i show right here is that this is the simplest formula.
03:52
You can calculate, we assume that the concentration is much higher than the total concentration is much higher than actual concentration in the ions...