 So, let's write the dehydration equation of sodium sulfate-decahydrate, okay? So, sodium sulfate-decahydrate, I know it's written up there for you, but I'm going to figure out how to come up with that formula, okay? So, sodium sulfate. So, sulfate, well, we know sodium is in a plus, right? That's the common ion for sodium, is everybody okay with that? Sulfate, you're going to have, that's one of those polyatomics that I wanted you to remember. So, I know everybody's looking up there, so I'm not going to ask you what sulfate is. But if you don't know it, you know in your head that you don't know it, so learn. It's SO4 2-minus, okay? So, sodium sulfate part, if we were to put that together, would be Na2SO4. Is everybody okay with that, right? Because we need to use sodium to cancel out that 2-minus. Everybody cool with that? Then the decahydrate, okay? Deca means 10, and when it says hydrate at the end, that's just water molecules associated. So, what we would do is write that little dot, 10 H2O, okay? And that's a solid, so I'm starting to write the chemical equation, okay? So, if it said write the chemical equation of the dehydration, do you think you could do that, right? So, help me out. So, what would I do? I'd write the reaction arrow. I'd show that we were heating it up, because that's how you're going to dehydrate these things. And remember, you do this in lab, so you heat these things up, stir them around, and then they lose weight, right? Okay? So, there's going to be two products that I'm going to show over here, right? What's the first one going to be? Sodium sulfate, very good. Is there going to be a coefficient in front of sodium sulfate? Anyone? No. Very good. And then I'm going to, well it's going to be a solid, okay? Then I'm going to add that to what? H2O. H2O, but how many of them? Ten of them. Ten of them. A lot? Because ten are coming off there, okay? And if I'm saying the dehydration, remember, that's gaseous water. Using this, you could figure out, you know, weighing the before and after, how much water came off, or whatever. And again, that's all due to the law of conservation of matter.