Critical Behavior of the Electrical Conductivity for the Binary Mixture of Water and Phenol

Abstract

The dynamic viscosity was measured for water-phenol binary mixture at several concentrations and temperatures to determine the critical concentration and critical temperature. The critical concentration was determined at XC=3.90% by weight of phenol, the critical temperature was TC=67.0°C using the viscosity measurement while TC=67.8°C from an indication of electrical conductivity measurements. The electrical conductivity measurements were recorded for water-phenol binary mixture at different temperatures and concentrations. The electrical conductivity measurements for various concentrations (0.00%, 10.17%, 20.80% and 50.00%) by weight of phenol were fitted by using Arhenius equation. The activation energy and the electrical conductivity at infinite temperature were calculated for several concentrations. The electrical conductivity as a function of temperature was fitted by using power law above the critical temperature. The noncritical part of the measured electrical conductivity was found to be 30.26 μS/cm and the critical exponent value was 0.0321. The molar electrical conductivity was calculated and plotted by using Walden rule. The slope of Walden plot was found to be 0.9439 so the water – phenol mixture was classified as a poor ionic mixture.