It has been almost one century since
Onsager developed the limiting
law of equivalent conductivity of electrolyte solutions. Thenceforth,
many models have been developed; however, they have not been assessed
thoroughly and systematically. This paper comprehensively investigates
the accuracy and reliability of six equivalent conductivity models,
namely, the Debye–Hückel–Onsager limiting law
(DHOLL), extended law (DHOEE), smaller ion shell (DHOSiS), along with
the simplified and full mean spherical approximation (MSA, MSA-Simple),
and Quint–Viallard (QV). To this aim, we have prepared a database
of experimental data for 126 electrolytes. The accuracy of the models
is examined with the help of graphical methods and error analysis
over a wide range of concentrations ([0, 18] mol/L) and temperatures
([0, 100] °C). Moreover, the origin of possible errors of models
is inspected with a term-by-term analysis of relaxation and electrophoretic
effects. It is shown that the absolute average deviation of models
depends highly on the electrolyte type, and it is generally smaller
for 1:1 salts, especially at low concentrations (less than 5%). The
error evolution with concentration also reveals that MSA-Simple and
DHOEE are more reliable over a wide range of concentration and electrolyte
types. It is concluded that MSA-Simple predicts the equivalent conductivity
at lower temperatures and the trend of Λ versus T more satisfactorily than the other models.