1. The problem statement, all variables and given/known data Ok, so, I've been thinking about this for a while now. When I was doing titration back in high school, we had to put water (so that the solution would have a larger volume to work with) in the acid in which we were going to pour base from a buret. Now, my question is this: Why doesn't the water change the pH of the acid? You add more water which dilutes the concentration of H+. So, then, there is the equilibrium formula: K=[H+][A-]/[HA] Since you dilute the solution (let's assume by doubling the volume of the solution), the K changes: [0.5H+][0.5A-]/[0.5HA] So, equilibrium constant is not the same anymore. Shouldn't this cause changes in the concentration of the acid and thereby false the titration? I feel there is something that doesn't click here.