 Okay, so let's do this one here, this reaction, and figure out, well, if the yield of this reaction is only 57.1% and we started with 12.3 grams of aluminum, what's the mass of iron that we would have after the reaction is over? How will we do that? You guys can help me along if you would like. I would like. Okay? So what do I have to do first? So I'm not looking for the mass of aluminum, what am I looking for? Iron. Mass of iron, right? So the first thing we're going to have to do is figure out what the theoretical mass of iron is, okay? And how will we do that? Just like how we normally do it, okay? So how do we do that? We're going to convert that to moles, right? So how do I do that? I look up at the periodic table. So it's a two-to-two ratio, right, like that. So that's moles of iron, and we could stop here if we wanted to, because that would give us the moles, and then we'd just calculate what the moles would be at 57%. Or we could go to the mass, okay? Let's just stop here at the moles. This is kind of what you guys did on your problem, what was it, four on your pre-live question. 12.3 divided by 26.98 times 2 divided by 2, we'll have to do that, 0.456, we'll say, moles. Okay, so is that the answer to this question? What is this the answer to? What question is this the answer to? That's the theoretical yield, right? That's a theoretical yield in moles, of course. Usually you want to think about putting it in grams because you're going to usually be weighing it in the lab, okay? But we can use this for right now. So if you recall, like what percent is, and percent yield is no different than any other percent. So percent yield is going to be the actual yield divided by the theoretical yield, 100%. So do we know the percent yield? Yes. Do we know the theoretical yield? Yes. Do we know 100%? Yes. We don't know actual yield, right? So we're just going to have to rearrange this equation, solve for actual yield. So percent yield, okay, let's do it this way, so it makes it easier for you guys. So percent yield times, I'm just going to put theoretical yield like that, divided by 100%. That gives us our actual yield, is everybody okay with that? When you do times the percent yield, is it 57.1 or 0.570? What is it? Is it 57.1 or 0.570? 57.1. 57.1, how, how come it has to be? Because it's 100%. You've got to cancel all your units. For those of you who refuse to want to put units on anything, you're just making it so hard for yourselves, because you're just going to tell me the wrong answer every time. This has the percent sign on it, right? to it. The theoretical yield, well what is the units of that theoretical yield? That moles, right? So the actual yield we want in what also? Moles. So since this has 100% in there, then the percent has to be in there, right? Okay, so the percent yield was 57.1% divided by 100%, right? It's 4456. Oh, okay, sorry. Cancel, cancel, like that, and that gives us the number of moles, which is times 57.1 divided by 100. 260 moles of ion is what we got, right? That's the actual yield in moles, but in the lab it's probably best to talk about grams because that's what we're going to be weighing at the end, right? So we're going to convert this to grams at the end. How do we do that? Some sort of conversion factor, right? What is it called? A molar mass. Yes. How many grams of iron did we get at? 14.5 grams. This is the question that you asked, essentially, yes. Would it be easier if you just, like, because when I blended it before, like, we were taught, like, when you do the mole, like, when you got the 0.456 mole, you go ahead and just convert that to grams and do it that way instead of having that. I mean, it's the same thing. Yeah, it's the same thing. It's like, do you want to put your left foot first when you want it, or do you want to put your right foot first? Yeah, as long as you get the right answer, you can do it however you want. You don't have to do anything except forget the right answer. Any other questions on this one? Cool.