Okay? Now, one last note about this is that our range for PH can range anywhere from zero to 14, where zero is the smallest possible PH and 14 is the largest possible PH. So let's look at this size. So at 25 degrees Celsius, we say that a PH of seven is neutral. And that's because PH of seven is smack in the middle. PH of water is seven because we have just as many H ions as we have hydroxide ions.