Tham khảo tài liệu 'electromotive force and measurement in several systems part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Electromotive Force Measurements and Thermodynamic Modelling of Sodium Chloride in Aqueous-Alcohol Solvents 95 Number of experimental points -Eox 103 V Pwaci kg-mol-1 Pỉỉảa kg-mol-1 So E X 104 7 8 9 10 11 12 13 14 Table 4. A comparison of Pitzer s model parameters with various set of input EMF data. The NaCl-H2O-C2H5OH system wt. at K. For the estimation of model s type influence on the results of calculation the Pitzer theory was compared with the more complex Pitzer-Simonson model. According to the Pitzer formalism the mean ionic activity coefficient of a strong electrolyte is defined within the molality mode related to the ideal dilute standard . But the definitions which use mole fractions are more suitable or even necessary for the calculations of phase equilibria. The Pitzer-Simonson model is based on mole fractions. So initial values of Y NaCl were at first converted to the mole fraction basis by the equation ym l w l 15 where Ms - is the mean molar mass of solvent. Calculated activity coefficients Yr were compared with those obtained by Eq. 13 . This equation includes two groups of parameters for the description of the Gibbs excess energy of mixing in the frame of Pitzer-Simonson formalism three pairs of binary parameters salt-water alcohol-water salt-alcohol and one ternary parameter. The long-range parameter for sodium chloride in diluted range Bmx and short-range interaction parameters IViNaCi and JiNaCi related to salt NaCl and water 1 were estimated on the base of literature data Pitzer Mayorga 1973 and own experiments. Results of calculation are presented in the Table 5. The binary interaction parameters for a .
