Autori: Florinela Sirbu,*,†,§ Olga Iulian,‡ Alina Catrinel Ion,‡ and Ion Ion‡

Editorial: Journal of Chemical & Engineering Data, 2011.

Rezumat:

ABSTRACT: Potential difference measurements have been used to obtain the mean ionic activity and osmotic coefficients of NaCl
and Na2SO4 in their aqueous solutions. Also, the mean ionic activity coefficients of NaCl in NaCl
Na2SO4
H2O ternary system
with sodium as a common ion have been determined from cell potential measurements using: Na-ISE/NaCl (mNaCl); Na2SO4
(mNa2SO4)/Ag/AgCl combined with the reference cell: Na-ISE/NaCl (I =mNaCl + 3mNa2SO4), AgCl(s)/Ag. Themeasurements were
made at ionic strength ratios for Na2SO4, yNa2SO4, of (0.0, 0.2, 0.4, 0.6, 0.8, and 1.0), at constant total ionic strengths, I, of (0.1, 0.5,
1.0, 2.0, 3.0, and 4.0) mol 3 kg
1 and at temperatures of (298.15, 303.15, and 308.15) K. The experimental mean ionic activity
coefficients of NaCl were correlated and analyzed with the Harned rule and Scatchard and Pitzer models. The excess free Gibbs
energies of mixing were calculated from the trace activity coefficient data of NaCl and analyzed versus system composition

Cuvinte cheie: mean ionic activity, osmotic coefficients, electrolytes