 Okay, so this one's a little different. We do have to remember what we had talked about earlier today about the strong acids, okay? So it says what is the pH of 1.0 times 10 to the negative fourth molar HCl solution, okay? So we know what the concentration of HCl, that the formula H3O plus concentration, right? Or the H plus concentration, whichever one you want to do. Let's just do H plus, please, okay? Do we have that number? Are they H plus concentration? Is that given to us in the equation? Uh-uh, so we've got to remember something. We've got to remember what happens to HCl when it's put into water, okay? What happens to it? It's a strong acid, so it does what? Completely dissociates, okay? Very good, that's very good, do you remember? So let's do the reaction equation. And again, H plus, H3O plus same thing, right? HCl, do the easy one, right? So breaks up into H plus plus Cl minus, like that, okay? And it's a straight arrow because it's a strong acid that completely dissociates. So if you wanted to, I can see some of you really wanted to, concentration of this, so if you remember from, what was it, chapter 8, right? When we're doing the mole going in the reaction equation, moles of one reactant to find the moles of the product, right? So we know the number of moles of this, right? The molarity of this. So we should know the molarity of these two, right? What's the ratio from this to this to this? One to one to one, right? So the concentration of this should be the same concentration as this and the same concentration as this, okay? So if we know this concentration, we also know that H plus concentration, we also know the Cl minus concentration for that matter, not that it's going to help us in this reaction, but are this problem. But we do know that, we need to get in because it'll confuse you. Again, try real hard with those sig figs, okay? It's not always the easiest thing to remember, especially for you guys. Notice, no units. Is this acidic, basic, what? Acidic, right? Why? Below four. Oh, below seven, sorry, it's not below four. Below seven, so, so.