 Okay, so we'll try this one. This one's pretty basic one. It says how many moles of oxygen Well, you need to react with 2.25 moles of nitrogen Okay, so normally we would want a conversion to go from one thing to another Right, what are we going from in two? We've got moles of nitrogen and we want to go to what? Moles of oxygen. Okay, where are we going to get that conversion from? The molar ratio. Okay, so what would that molar ratio be? Can we write it down somewhere over here? What would it be? One mole of nitrogen One mole of oxygen. Is that the form that we're going to use for this equation? Are we going to put what are we going to put on the bottom? We're going to flip it over, right? So what are we going to put on the bottom? One mole of nitrogen. Why would we put that on the bottom? Yeah, because we're going to cancel out the moles of nitrogen, right? What are we going to put on top? One mole of oxygen. Okay? Cancel. Cancel. Do we need a calculator to do that one? Yes. Yes. 2.25 moles of oxygen. So that's how many moles of oxygen you need to completely react with 2.25 moles of nitrogen. So that's how you do it. Okay? Questions on that one? Okay, pretty easy one.