 Okay, so this one says dimethylamine CH32NH has a KB of 5.9 times 10 to the negative 4th. What is the pH of 1.5 molar solution of dimethylamine? So that's all the information the problem gives you. So from this, you're going to have to figure out what the reaction equation is. So first thing, let's write that reaction equation. Hopefully you guys can do this on your own. I think they're moving this. Everybody was able to do something like that. Now you're going to want to write an ice table, just like always. So these problems are fairly standard. So remember when we're doing any of these weak acid, weak base ones, we can also apply our 5% rule whenever we're doing this. You can look and see it's a very small number. So it gives us 1.5 molar to start out with. We'll start it out with 0 and 0 there. The change would be, well, of course, minus x there, plus x there, and plus x there. So 1.5 minus x kb's equation is going to be the concentration of protonated dimethylamine, which is OH minus, by the concentration of dimethylamine. So what did we say? Well, because we're invoking the 5% rule, 1.5 minus x equals 1.5. So we can do that. We have the kb here. So we've got x here, x here, 1.5 here. So let's rearrange this thing. So remember x is going to equal this and this. So it equals the concentration of OH minus. And also the concentration of the protonated. Is everybody OK with that stuff? OK. So what are we looking for? I forget. OK, pH, right? So pH, well, we can either use this to get our PoH, right? And then subtract that from 14. Or we can use that directly with kw, OK? So can I erase this part over here? Well, why can't I erase this whole ice table? That would give me enough room. Is everybody OK with that? So it's kw. So to figure out what the concentration of H3O plus is, kw divided by the concentration of OH minus. kw, of course, is 1.0 times the concentration of 14 divided by, as you might imagine, this would be very high on the OH, right? So it's going to be very low on the H3O plus. Is everybody OK with thinking like that? OK, so from that, remember the pH equals the negative log of the H3O plus concentration, OK? So pH is going to equal negative log of 0.4 times 10 to the negative 13. So just like how we did at the ice tables for the weak acids, we can do them for the weak base, OK? Just remember when we do it for the weak base, we're getting OH minus. And from there, that's how we're getting our pH. We've got to turn it around to H3O plus, OK? So is this a basic solution? This would be a basic solution, yeah. Let's think about that, right? So if your OH concentration is bigger than your H3O plus concentration, then that's a basic solution. Should we get you kw? That's something you want to remember. kw is always that constant. 1.0 times 10 to the negative 14. So yeah, this is the basic solution. This is small. This is small. It doesn't matter how you get the pH numbers as long as you get the samples. I got small samples. Yeah, you could go the other way. I got the OH and then go the other way. Yeah. I just prefer to do it this way. I don't know. Does it help when we're complicated problems just to stick with that? No, I mean, I just stick with this because this is the way I like to do it. But POH works just fine, OK? In fact, as you saw, you know, you can get the same answer. And it's OK to do it either way. Yeah, I think that you got it best, really. OK? Any other questions? OK.