Limiting Conductivities of Strong Acids and Bases in DO and HO: Deuterium Isotope Effects on Proton Hopping over a Wide Temperature Range.

The molar conductivity (Λ°) of hydrochloric acid, potassium hydroxide, and sodium hydroxide has been measured in both light and heavy waters from 298 to 598 K at = 20 MPa using a high-precision flow-through alternating current (AC) conductance instrument. The results were used to explore the deuterium isotope effect on ionic transport by proton hopping mechanisms under hydrothermal conditions. Extrapolations of published transport number data to elevated temperature were used to calculate the individual ionic contributions (λ°) for HO, DO, OH, and OD, from which the excess molar conductivities due to proton hopping were calculated.