ELECTRICAL CONDUCTANCES OF AQUEOUS HYDROGEN BROMIDE SOLUTIONS FROM 0 TO 800 DEGREES AND AT PRESSURES TO 4000 BARS

The electrical conductances of dilute (0.002 to 0.015 m) aqueous hydrogen bromide solutions have been measured at temperatures to 800° and at pressures to 4000 bars. Limiting equivalent conductances for HBr were calculated at integral temperatures and densities under conditions where it behaved as a strong or moderately strong electrolyte. Hydrobromic acid becomes progressively a weaker electrolyte as the temperature increases and the solution density decreases. Equilibrium constants for the ionization of HBr were calculated from the conductance measurements at temperatures of 400° and above, and at densities below 0.85 g cm-3. By considering hydration to be an essential part of the ionization process, values of the isothermal equilibrium constant were obtained that were independent of density.