Concentration Dependence of Surface Tension for Very Dilute Aqueous Solutions of Organic Nonelectrolytes

Surface tensions of pure organic compounds and their dilute aqueous solutions (molar fraction typically
x2 < 0.015) at 298.15 K have been measured. The Szyszkowski equation has been used for correlation of
the experimental surface tension data, and the ability of the equation to describe the concentration
dependence of surface tension has been tested. When accurate values of surface tension were known, the
Szyszkowski equation has been found to not be suitable for correlation, especially in the case when values
of the first derivative, obtained from the parameters of a correlation equation, have been wanted. Therefore
values of limiting slopes of surface pressure concentration dependence have been evaluated by a linear
regression of the most dilute results (typically x2 < 0.001).