 Okay. So aqueous solutions of sodium hypochlorite, best known as household bleach, are prepared by reaction of sodium hydroxide with chlorine gas. How many grams of sodium hydroxide are needed to react with 25.0 grams of chlorine? So the only thing, oh, and then it gives us the reaction equation. So the only thing, other thing that it gave us was the mass of chlorine gas, right? So chlorine gas was 25.0. And it wanted to know, well, how much sodium hydroxide would we need to completely react with that 25 grams? So does everybody understand what it's asking? So remember the, so I guess I'm going to give it away since this is the first one we're doing today and I don't want to push you guys to hardball recording. But remember that the reaction equation gives us a mole to mole ratio of these various substances that are reacting and forming in the actual reaction. Is everybody okay with that? So it's a mole to mole ratio based on the coefficient in front of each one of those individual species or substances. Is everybody okay with that? Okay. So let's just go ahead and underline the coefficients. Remember, if the coefficient is one, it's just implied it's not there, you know, so we don't actually formally put it. I'm going to eventually stop doing this for you guys, but for right now I think it's a good thing. So in other words, since it's a mole to mole conversion and it wants us to eventually convert chlorine to sodium hydroxide, that gives us the actual ratio of the mole to mole conversion. So in other words, I'm just going to write that ratio really quick. So two moles of sodium hydroxide equals one mole of chlorine dex. Is everybody okay with me doing something like that? So that's eventually what we're going to need. The first thing we need to do though, if we're going to get to moles of chlorine, right, and we have grams of chlorine, we've got to get, yeah, we're going to have to get the moles of chlorine. How do we do that? Mole or mass, right? So if we look up at the periodic table, it's 3545, so 35.45 times 270.90 grams of chlorine. One mole of chlorine. Okay, I'm going to not do this, I'm not going to solve every step. I'm going to just keep going along on the conversion train here, okay? So I'm going to be able from that to cancel out my grams of chlorine. Is everybody fine with doing that? So now we're at moles of chlorine. Remember, we wanted eventually to get, I think, grams of sodium hydroxide, right? Yeah, right, that's right. Grams of sodium hydroxide. So firstly, we need to get to moles of sodium hydroxide. Okay, so using that conversion factor that was derived from the chemical equation. So now, we've got to figure out, well, what's the molar mass of sodium hydroxide? If you, I'm just going to do it on my calculator, I'm not going to formally write it out. If you're having trouble with that, please go back to the molar mass figures, okay, and check it out. So, sodium 22.99 plus oxygen is 16 plus hydrogen is 1.08. So, I got 40.00 grams of sodium hydroxide. One mole. I'm doing it the wrong way though. 40 grams of sodium hydroxide. And of course, the reason I was able to figure that out, even though I know Justin almost caught me, right, before I figured it out, was because I looked at my units and I would realize that, you know, I had them inverted. I couldn't cancel them. And then, she gave me the answer. 36 bigs. Okay, any questions on that one?