 So, this problem asks us to predict whether the aqueous solution of potassium perchloride, which is written up there, is going to be acidic, basic, or neutral To do so, we have to remember our rules So if you recall, when we react or when we put a strong base into water, it fully dissociates and when we put a strong acid into water, it fully dissociates And what happens when we react a strong acid with a strong base is that they react completely if they're of equal molar concentration as of protons and hydroxide ions and they'll form water and salt, okay? So the way we want to look at these particular problems is to think of, well, if we reacted the base and the acid from these particular ions that we would get, right? So what do we get out of this thing? Well, we get the potassium ion and the perchloride ion So, when we're looking at the reactions of these things, well, how did we get to these? Well, this must have come from HClO4, right? So that's the conjugate base of perchloric acid, which is a strong acid, okay? This thing, if we think of, well, what must this have reacted with to produce this? It's going to be KOH, okay? So this is not necessarily the particular reactions that occurred to get to this salt, but you can think of it this way, okay? So since we have a strong base reacting with a strong acid, right? To produce this thing here, right? Remember what we said with our rules is that the salt of a strong base reacting with the strong acid is going to be a neutral solution, okay? So if we look here, to get this salt, we could conceivably say, right, we've got potassium hydroxide reacting with perchloric acid to get potassium perchloride. So since we've reacted a strong base strong acid to get the salt of a strong base of strong acid, this is going to be a neutral solution, okay? So in other words, we don't have to do all of these reactions. We could just think, if I dissolve this thing into water, what will happen? Will it react with water or not? Will it remove the proton or will it donate a proton? It won't do either one of those because it's the salt of a strong acid reacting with a strong base, okay? Does that make sense? Are there any questions on that one? I know this is kind of a convoluted way, but the other ones are a little easier to look at. So we can kill that one, I guess.