EMF cell set-up and thermodynamic investigation of liquid Pb-Bi alloys at 550 and 575 degrees C

Activities of lead in lead-bismuth alloys at 550 and 575 degrees C are meas ured at various compositions i.e. at X-Pb = 0.1, 0.3, 0.5, 0.7 and 0.9 wt.% in galvanic cells of the type, Pb\LiCl + KCl + PbCl2\(Pb + Bi) Activity and activity coefficients of lead and bismuth, par tial molar and excess partial molar free energies of lead and bismuth are calculated and t abulated at X-Pb = 0.1 to 0.9. By taking calorimetric Delta H values, Delta S and Delta S-ex values an calculated and tabulated. All these thermodynam ic functions are internally consistent and also consistent with other publi shed data. The variation of Delta S-ex with composition, suggests that in t he liquid alloy segregation occurs at about X-Pb = 0.45 and association at about X-Pb = 0.65.