Changes in pH with Dilution
What is the pH of 1.0 x 10-7 M HCl?
What is the pH of 1.0 x 10-8 M HCl?
Why does the pH stop changing at a value of about 7?
Water has a pH of 7 due to autodissociation, so it is never possible to get a pH higher than 7 by addition of water.