Thermodynamic interpretation of the Eötvös constant

Abstract

Eötvös in 1886, proposed the following equation for liquids γ(Mν_sp.)^2/3=K_E (T_c-T) where γ is surface tension, M is molecular weight, ν_sp is specific volume and T_c is critical temperature, which is found to be strikingly valid over a wide range of temperature for most non-polar compounds. Even for polar compounds the equation is valid though to a more limited extent; but the value of the constant, K_E, is often very different from the usual value, 2.12. This empirical equation has been given some theoretical support (cf. Partington). The purpose of the present communication is to point out a simple thermodynamic interpretation of the above equation.