 Let's do a volume to volume one. So this one says, how many liters of oxygen react with 37.5 liters of sulfur dioxide in the production of sulfur trioxide gas? And the balance chemical equation is given to us. So we're at liters of sulfur dioxide, and we want to know volume of oxygen. What's the first thing we need to do? Always. Well, the balance of the equation is already balanced, right? So moles, right? So what's on the bottom here? Very good. 22.4 liters of sulfur dioxide. And on the top, one mole sulfur dioxide. Then what? Yeah, we're going to do the mole to mole ratio. Very good. What's on the bottom here? Two moles of what? Sulfur dioxide, and on the top? One mole of oxygen. So now what do we want to do? Yeah, we use the molar volume to convert what? One mole of oxygen. Yeah, mole into liters. So what's on the bottom here? One mole of oxygen. Yeah, one mole of O2 on the top. 22.4 liters of oxygen. 22.4 liters of O2. Are we at what we want? Volume of oxygen? Yes. Yes, we are. So again, just got to figure out what am I canceling out, and what do I want in the next step. So everybody try it with me. 37.5 divided by 22.4 divided by 22.4. And to three sig figs, OK? So this one's going to be 18.8 liters of oxygen. Very good. Very proud of you. Doing awesome. All of you are doing awesome. Questions on this one? Wonderful, wonderful.