On autoionization and pH of liquid water

The ionization constant of water Kw (or pH) is currently determined on the proton conductivity σ0 which is measured at frequencies lower than 107 Hz. We develop the idea that the high frequency conductivity σ∞ (~1011 Hz), rather than σ0 represents a net proton dynamics in water. We count the concentration c of the H3O+ and OH– ions from σ∞ to find c to be not dependent on temperature. We conclude that spontaneous ionization of H2O molecules is not essential in water electrodynamics; the common Kw reflects the thermoactivation of the H3O+ and OH– ions from the potential of their interaction; the lifetime of a target water molecule does not exceed parts of nanosecond.