The fraction of time during which a molecule of a pure alcohol does not undergo H-bonding, estimated from the vapor pressure, is two orders of magnitude larger than the fraction of molecules that at a given time are not bound by an H-bond to their neighbors, as deduced from IR spectroscopic data. This obviously “anti-ergodic” statement renders questionable all the thermodynamic treatments of H-bonding in liquids, which are based on the usual Boltzmann expression. This expression equates the thermodynamic probability of a system with the static probability of distribution of the various states and, as outlined by Einstein, does not hold for non-ergodic systems. As pointed out by Pais (A. Pais, Subtle is the Lord. The Science and the Life of Albert Einstein, Oxford University Press, 1982), another Boltzmann relation relates the thermodynamic probability of a state to the fraction of time during which the system is found in that state. The latter definition was used by Einstein in his treatment of the ergodic problem. Similarly, the theory of the thermodynamics of mobile order in H-bonded liquids, of Huyskens and Siegel (P.L. Huyskens and G.G. Siegel, Bull. Soc. Chim. Belg., 97 (1988) 821), considers not the static configurations of the liquid, but the fraction of time during which an OH proton follows the oxygen atom of one or another neighboring molecules in its motion through the liquid. This coordination lowers the entropy and this reduction can be evaluated quantitatively. The present paper establishes a distinction between the static disorder, which is due to the possibility of exchange between the positions of the molecules and exists in mixed crystals, and the mobile disorder, which is due to the enlargement of the domain available for the motions of a given molecule, provoked by the mixing of two real gases. The mixing of two liquids allows an exchange in the positions, but also an expansion of the individual domains available for the motions. Thus, the disorder in liquid mixtures always has a hybrid character, partly static and partly mobile, and H-bonds in the liquid reduce the mobile part. From a quantitative point of view, this hybrid character can only be detected without ambiguity when the molar volumes of the components differ by a factor greater than two. The quantitative equations deduced from this new approach are completely confirmed by the solubilities of solid alkanes in liquid alkanes and in alcohols, and allow the correct prediction of the order of magnitude of the solubilities of liquid alkanes in water.