The ionic product of water in highly concentrated sodium perchlorate solutions

The ionic product of water, pK(w) = -log[H+][OH-], has been determined in aqueous solutions of sodium perchlorate over the concentration range of 1.0-8.0 M at 25°C from high-precision potentiometric titrations carried out in cells with liquid junction using both glass and hydrogen electrodes. The glass electrode results are systematically lower probably as a result of interference by Na+ ions