Proton transfer conductance in aqueous solution. Part 2.—Effect of pressure on the electrical conductivity of concentrated orthophosphoric acid in water at 25°C

Abstract

Data are presented for the effect of pressure from 1 to 3000 atm on the electrical conductivity of 1–15.7 M aqueous orthophosphoric acid solutions at 25°C. At low concentrations the conductance increases with pressure whilst at high concentrations it decreases, and at about 11.7 M the conductance is independent of pressure to 3000 atm. The results support our suggestion that the proton transfer mechanism of conductance in water is gradually obliterated as the solute concentration is increased, and at sufficiently high concentrations hydrogen and hydroxyl ionic conductance occurs by the hydrodynamic mechanism.