The Electric Conductivity of [Co(NH₃)₅NO₂]SO₄ Aqueous Solution under High Pressure

Abstract

The electric conductivity of aqueous Co(N113)511S04 solution was measured as a function of pressure (up to 3000 kg/cm2) for concentrations from 2.0x1O to 1.0 x 10 N at the temperatures of 15, 25 and 400C. The equivalent conductance at infinite dilution, A0, vs. pressure curve has a maximum. The pressure at this maximum conductance was found to be higher than that at the minimum viscosity of water at each temperature. These phenomena may be attributed to the decrease in the effective radii of the hydrated ions with increasing pressure.
Thehydration numbers of the ions estimated by the Robinson-Stokes method are littlechanged with pressure and temperature.
Both the closest approach distanceof the ion-pair, a, calculated by using the theoretical equation of Fuoss and the thermodynamic parameter, AVO, calculated from the pressure coefficient of the dissociation constant suggest that the ion-pair, Co(NH3)5NOj2 .S042, exists in closer contact as compared with that in a simple 2-2 electrolyte,