 Okay, so let's do this one now. It asks us to decide which reaction describes the complete combustion of propane, okay? So when I am Combusting propane, which is written up here, C3, A, J, what am I reacting that with? Oxygen, so O2, okay? So that has to be present in our reactants, those two things, okay? And in fact, we're going to be balancing this equation. And it says complete combustion. So what does that mean? What two things am I going to be forming? Carbon dioxide and water. So I'll answer this and figure out which one of these has the same coefficients That is from the equation, I think that's okay. So can I cancel out any of these already without even looking at balancing it? B and D. B, definitely. Okay. D. D, why would you say that? It has a decimal 4.5. Oh, okay. Yeah, well, why would you say B though? Because of the carbon monoxide, right? Yeah, so let's not worry about that decimal yet, although that is a good clue, okay? But B for right now, because we see carbon monoxide, that's not complete combustion, okay? That's what I wanted to get across, okay? So now let's balance our reaction equation. So what do we do? We take C, H, and O, so remember here, we do C's and H's first, okay? So how many C's do I have? Three. Three. And H is? Eight. Eight. Okay, and we can write the two oxygens as well. C, H, O. So how many C's? One. Just one. H is? Two. Two and O's? Three. Okay. So first thing we have to do is balance carbons, then hydrogen, then go over here, and then balance back the oxygens, okay? So three. So we're gonna want to multiply that by three. Eight, okay? So if we have eight here, we've got two here, so we're gonna multiply that by four, right? So that's gonna give us three, that's gonna give us eight, like that. And then we got a question mark there, okay? So three there. Four there, okay? So now let's ask ourselves how many oxygens we have. So three times two is what? Six. Six. Plus four is what? Ten. Okay, so let's erase this thing. So that's how many we have now. Two times one equals ten. Five. Okay, so we want to multiply that by five. That equals ten. So now we've got three. Does that balance with three? Yeah. Eight, does that balance with eight? And now we've got to put a five up here, right, to make that ten. And then ten, does that balance with ten? Okay, wonderful. So this here is the complete combustion of propane. Do you see that in any of those? Yeah. Yeah, so that's how you do it. And you're absolutely right. About the 4.5, oftentimes, you know, when you see those things, that's almost always not the right things, okay? Occasionally it will be those, so watch out. Okay, any questions on that? Wonderful.