To determine the pH of a 0.10M potassium perchlorate solution, we need to consider the dissociation of the salt in water. Potassium perchlorate (KClO4) is a salt that consists of potassium ions (K+) and perchlorate ions (ClO4-). Since both ions are spectator ions, they do not participate in any acid-base reactions. Therefore, the solution remains neutral, and the pH is 7.

In summary, the pH of a 0.10M potassium perchlorate solution is 7, indicating a neutral solution.