New calorimeter for measurement of the enthalpy of mixing of liquids. The enthalpy of mixing of benzene with carbon tetrachloride and of n-hexane with cyclohexane

Abstract

A high-precision, mixing calorimeter is described for the direct measurement of the enthalpy of liquid mixing under constant pressure conditions. Tests of the calorimeter using the benzene – carbon tetrachloride system at 25 °C show a reaction between mercury and carbon tetrachloride which leads to systematically high values for the heat of mixing. Tests with the n-hexane–cyclohexane system at 25 °C give a maximum enthalpy of mixing Δmh = 222.14 + 0.21 J/mole at 0.586 cyclohexane mole fraction.