It seemed to me the more a polyprotic acid dissolved, the higher the amount of H+ ions would be in the solution, and therefore the pH value would be lower. However, in my textbook it looks like it's saying otherwise.
It shows the fractions of the species (undissolved acid, partially dissolved, and completely dissolved) as a function of pH, with the lowest pH values having the highest amounts of undissolved. What's going on here? Does it have something to do with the addition of another substance that contains common ions?
Any help would be appreciated!