The chemical effects of pressure: Part 3. - Ionization constants at pressures up to 12000 ATM

Abstract

The electrical conductances of aqueous solutions of five electrolytes have been measured to 12000 atm at 45° C. Those of ten other electrolytes have been measured to 3000 atm at 25° C. The abnormal conductances of the H 3O+ and OH- ions are found to be increased by pressure. The conductivity data have been used to derive the pressure dependence of the ionization constants of the bases ammonia, dimethylamine and trimethylamine, and of formic, acetic and propionic acids. The basic ionization constant of ammonia at 45° C is increased from 1·9 x 10-5 mole kg-1 at 1 atm, to 1010 x 10-5 mole kg-1 at 12000 atm. This change can be attributed to the greater hydration energies of ions at high pressures.