ACTIVITY-COEFFICIENTS IN QUATERNARY SYSTEMS - EXTENSION OF THE HARNED EQUATION

Activity Coefficients for NaCl and NaBr at 25 degrees C have been determined from e.m.f. measurements in the following cuaternary systems: NaCl+NaFor+NaAc+H2O, NaCl+NaFor+NaPr+H2O and NaBr+NaFor+NaAc+H2O (For=formate, Ac=actetate and Pr=propionate). The results have been analyzed by enhancing the extended Harned's rule. This enhancing considers all the cuadratic term parameters including beta(ij). Therefore, the equation becomes: log(gamma(1)/gamma(1)(0))=-alpha(1i)m(i)-alpha(1j)m(j)-beta(1i)m(i)(2)-beta(1j)m(1j)(2)-(beta(1i)+beta(1j)-beta(ij))m(i)m(j)