 OK, so let's try this one. This is essentially a problem figuring out what form will be present in the higher concentration of physiological pH. So this is not like how we were doing. We were reacting an acid and a base together before. This we're just sticking in water and seeing which species will dominate. And so you can think of the water as the base, if you will. So in this case, it says we're sticking pyruvic acid into water and physiological pH, which side is going to dominate. And I know it already gives you the equilibrium there, but we're going to figure it out. So remember, we can, of course, switch this around to where we take pKa on the other side, so pAa minus pKa, the log. And I'm just going to, instead of cA and conjugate basin, conjugate acid, I'm going to put cB and cA. So cA you can think of as the acid or conjugate acid, same thing. And then to get rid of this log, just take everything to the 10. The next thing you need to know, and this is just a number, I'll probably give it to you in the problem, but physiological pH is approximately 7.3. So that's what we're going to do these problems on. We're going to say, and at physiological pH, what species does. So you're going to have to remember that the pH for all these problems is going to be 7.3. Or unless I tell you it's a different pH, like in the example below. But if I say physiological pH, I mean 7.3, but I'm more than definitely will give that to you. And if I don't ask, OK. And then you also need to know, of course, the pKa of the conjugate acid. So what are we looking for? So everybody can see on the blackboard or I mean on the PowerPoint that this acid is up. This is pyruvic acid. Of course, this is the acid form of it. So what would pyruvic acid conjugate basically? But how would you do that? Let's write the mechanism. So remember, water is going to be our base. And where they put H plus up there? H plus and H3O plus are the same thing. You guys should be able to do this on your own. You don't have the best way to not write how the right mechanism is. I'm just telling you. I guess I shouldn't have put that. It shows it. Let's work wondering that. So we know pH here. That's here. pKa for a particular thing has to be given to you. So you can look in the pKa table and get kind of a range of what it would be if it's like a carboxylic acid or something like that. But again, if I say pyruvic acid, if I said general carboxylic acid, I could have you look on that pKa table. But since I said pyruvic acid, I would probably give you the pKa of pyruvic acid. So the pKa of pyruvic acid is 2.5. And from there, it's pretty straightforward calculation. So you just know that this ratio, here, and that's all you're looking for is that ratio, because which one, right? So that ratio is going to be 10 to the pH 7.3 minus pKa 2.5. So when we do that, we get 10 to the what? Good job, guys. 4.8. All of you got calculators? None of you could do that? OK, so is that bigger than one or less than one? Bigger than one, right? So what will we expect? More of the conjugate base or the acid? The base, right? So which one's the conjugate base? Which one's the conjugate acid? What's this one? Conjugate base? This one? Conjugate acid. Conjugate acid? So if we would expect, so this actual number, I think I thought it would be, again, 6, 3, 0, 9, 6. And notice the units of all of these, none, OK? Equally ring constants have no units, OK? So bigger than one or less than one? Bigger. So it's going to favor the conjugate base, because the conjugate base is bigger. The conjugate acid was bigger. This number should be smaller than one, not maybe. It has to be bigger than 0, because you can't have it. So this is not a question anymore, like that. Fairly much, right? That's a huge number. I mean, it's not the biggest number I've ever seen for an equilibrium constant, but are we cool with that? OK, so again, I mean, look at the next question, and it's very similar, OK? So anyways, I'm going to kill this one. Is that OK?