 Okay, wonderful. Let's do one of these balance chemical equation and then do grams to grams, mass to mass, right? So what does this one say? It says, what is the mass of calcium phosphate that can be prepared from 1.78 grams of sodium phosphate? And then it gives us the equation, but doesn't give us a balanced equation, okay? So what we need to do first is to balance the equation, okay? So what did we say? We've got three sodiums here, only one here. So we do a three there, right? So that's going to give us OHs of three and we have two OHs here, so we can't have that, right? So the three over there because two and three don't divide evenly into each other, right? So when we do that, we're going to have to put a three there and that's going to give us two times three is six, right? So we come over here and put a six there. That's going to give us six OHs there, right? And we have six sodiums now, but if we look over here, we've only got three. So we're going to want to put a two there. That makes sense, right? So two times three is six, six, so we're cool with our sodium. Phosphate, PO4, remember, is all phosphate, okay? So we've got two of those and look over here, we've got two of those, so that's good. And then the last thing is calcium. We've got three of those and three of those, okay? So we're good with the balancing of the equation. Okay, wonderful. So the next thing we're going to have to do, remember, we have to use that equation to get the mole to mole ratio of these two things, right? I didn't ask this, it was nice enough to us so we don't have to keep going back. It asked us to do calcium phosphate to sodium phosphate, okay? So let's look at that mole ratio and it's up here, right? We've got two moles of sodium phosphate for every, how many moles? Three. Just one mole, one mole, because remember, there's implied one, okay? It's not three, because that just tells you how many calcium atoms, right? We're talking about the whole thing, okay? So where does the mole ratio come from? It's from the, what are these things called? The coefficients, okay? So what do we have? We have a two to one mole ratio, okay? So let's write that down somewhere, okay? So let's say, because that's gonna be our conversion factor, remember? Okay, yeah, for the second part, very good, yeah. Okay, so let's write it down. So for every two moles of MA3PO4, we've got that equals one mole of CA3PO2, okay? That makes sense, right? Okay, wonderful. But the problem is, is that it gives us in grams, okay? And to convert grams to moles, we need to use the molar mass, right? Remember the molar mass? So what do we have to do? Well, we gotta get the molar mass of sodium phosphate and it doesn't give us to us. So we're gonna have to figure that out, okay? So that's where we go to the periodic table and we look at sodium, it says 22.99 and we look up here, we've got three of them, right? So three sodiums in every sodium phosphate, so we multiply that by three and then add that to, well, how many phosphorus, just one, right? So we look over here. 30.97 plus 30.97. And then how many oxygens do we have? Four. Four, so we're gonna have that to four times 16.00. Okay, so the number I get, hopefully it's the same number you get, okay? So I'm going, I want you to calculate it at the same time. If we get different numbers, then it's your calculations that that's where you're having a problem, okay? So the number I got is 163.94 grams of sodium phosphate. 163.97. Firm mole. Here, we'll say grams per mole of sodium phosphate is even better, we'll just think of that. Grams per mole of sodium mole. Did you get that same number there? Yeah. So look if we could do now. If we flip this thing over, right? We can use that conversion factor here. In fact, let's erase this to make it look a little bit nicer for us if I can find my eraser. So instead of doing that, we'll say per one mole, right? NA3PO4, right? NA3PO4. So if we flip this thing over, right, what do we have? We could put one mole up here and that may be grams down there, right? Just cancel out. Yeah, so that'll cancel out grams of sodium phosphate. 3.94 grams, okay? So now we've got the number of moles of sodium phosphate, right? But we're looking for the mass of calcium phosphate. So that's not the same thing as the number of moles of sodium phosphate. But what's cool is we can take this number of moles of sodium phosphate and get the number of moles of calcium phosphate, right? How do we do that? That is for the two moles. From that conversion factor up there, that would be very good, right? So what are we gonna put on the bottom here? The two moles. The two moles, because that's the sodium phosphate. Yeah, very good. Yeah, so you get the process. I think it's just you put plug something wrong in your calculator. And I'll bet you it's even, it's like, if you put parentheses around the right things or the wrong things, your calculator's gonna think differently than what you think, you know? So we'll just figure that out. Like how you're plugging it in and then get that all straight. So we cancel, cancel. And now we're at moles of calcium phosphate. Remember, we want grams of calcium phosphate. So in order to do that, we need the molar mass, right? So let's go and do that again. So we have three calciums. Calcium is 40.08 times three, so plus, here we got two times P, right? So two phosphorus, so plus two times 30.97. And then we're gonna get two times four oxytones, right? Which is eight oxytones, times 16.00. And then when we do that, and I'm just gonna write it just like how I have this one here, okay? So three 10.18 grams of calcium phosphate per one mole of calcium phosphate, okay? So now we can plug that into our conversion factor just like how it is because remember, we're looking for grams, so we want that at the top, right? Okay, and we wanna cancel out our moles, so we want that at the bottom. So we say for every one mole of calcium phosphate, like that, we got 310.18 grams of calcium phosphate. So that will cancel like that, like that. Now remember, we're looking for the mass of calcium phosphate, and what do we have here? Grams of calcium phosphate, that's the mass, right? Okay, so all we have to do now is take the numerators, multiply them all the way across, and then divide them by the denominators, okay? So I'm gonna take 1.78 and multiply it by 310.18 because one and one don't do anything to it. Okay, so you don't have to multiply 163? No, so this is where your problem is going, okay? So you're gonna take 1.78, multiply it by 310.18, okay? So you see how I've done that here? Okay, push the enter, and I get like 552 something, okay? Then I'm gonna take that number and then divide it by 163.94, then push enter, okay? So this is your problem, right? Yeah, you start with the right one. So I'll start this one and divide that whole number by that, okay, and then I get 3.36. Then I'm gonna take that number and divide it by two because that's the next one over here. And then that number I get, that's the answer, okay? It's gonna be 1.68 grams of calcium possible. That's your answer, okay? So what I'm going to do, we're gonna kill this video and then what I'm going to do is I'm gonna have you practice calculating these types of things, is that all right? Okay, are there any questions besides that last portion of calculation? No, it's all right. Because everything else, it seems that you're like point on, right? Yeah, okay. Cool, yeah. Okay, that's a really easy problem to figure out, okay?