 Let's try this problem. 25.0 mill sample of dilute acetic acid is titrated and found to react with 94.7 mills of 0.2 molar and AOH. What's the molarity of the acetic acid solution? So we're looking for the molarity of CH3COOV. We know the volume of acetic acid that was titrated. It's 25.0 mills. We also know the molarity of NaOH, which is 0.200 molar. And we know the volume that was used to titrate the 25 mills is 94.7 mills. So notice a lot to the left. Can you guys see that? And notice it's 1 to 1. So you should be expecting some things already to say, well, this might be more concentrated, or something like that. OK, so how do we go about doing this? Well, we could do it a number of ways. But let's figure out how many moles of NaOH are in 94.7 mills, in particular this 0.2 molar NaOH. So in order to do that, and this is going to be of the NaOH solution. So I'm just going to put solution. The molarity of NaOH, remember, this is not just big M, but we can convert that to a conversion factor. Moles of NaOH, 1 liter of solution. OK, so now we could probably figure out, well, how many moles of NaOH we have. 94.7 milliliters, right? You think we could do that? So that should give us the moles of NaOH. Is everybody OK with that? We'll do this one stepwise. Again, you don't have to do this stepwise. You can do it all in one fell swoop, like I was doing earlier. So that's moles of NaOH, right? That's not what we want. We want to, well, we've got to figure out how many moles of acetic acid we have. So, but what do we know about the mole-to-molar ratio of acetic acid to NaOH? More than one to one. So it actually is the same amount of moles. But let's just convert it. From that, do you think we should be able to figure out the molarity of acetic acid? You think so? You just telling me that? How do we do it? You've got to figure this out, OK? And that's going to be, OK? So that's liters of the acetic acid solution. So that's the moles of acetic acid. And to do molarity, we're looking for moles divided by liters, right? What did you guys get? Did anybody do this because I didn't know, buddy? I got 0.758 moles of acetic acid. Did anybody else get that? Did you get that? OK, good. Cool. Not the only one. Any questions on that before we kill it? Questions, questions? OK, good.