Collect. Czech. Chem. Commun. 1981, 46, 1930-1940

A re-examination of the Eötvös equation

Otto Exner

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


The Eotvos equation (1) was re-examined from a purely empirical standpoint on a restricted but carefully selected set of compounds; the main intention was to test how an empirical equation of several variables can be verified by experiments. At a fixed temperature Eq. (1) is able to predict one of the three experimental quantities - surface tension, density, critical temperature - from the remaining two with a fair precision, but the range of validity as to the structure is rather restricted. At variable temperature and for a given compound, Eq. (1) describes the temperature dependence of surface tension provided the temperature dependence of density is known; however, the precision is low and a simpler and a more effective equation can be derived. If both temperature and structure are varied, Eq. (1) infers relationships of very low precision or even clearly invalid.