Thermodynamics of the cell : {NaxHg1-x|NaCl(m)|AgCl|Ag} in (methanol + water) solvent mixtures

The emf. E of the cell {NaxHg1-x|NaCl(m)|AgCl|Ag} was measured at the temp. 298.15 K as a function of the mole fraction x of Na metal in amalgams and of the molality m of NaCl in (methanol + water) solvent mixts. contg. up to 0.8 mass fraction of methanol, with relative permittivities ε ≥ 40. The resp. std. electromotive forces Emo were detd., together with the activity coeffs. γ± of NaCl as a function of its molality. For interpolation purposes the Emo values can be expressed as a function of the methanol mass fraction wM by the following polynomial, valid for 0 ≤ wM ≤ 0.8: Emo/V = 2.18126 - 0.092727·wM1/2 + 0.10309·wM - 0.24716·wM3/2. These results for std. emf.s. lead to a primary hydration no. nhydr ≈ 7 for NaCl which is in good agreement with previous results using different methods