Thermodynamical Significance of Salinities in Seawater and Human Blood and the Effect of Dissolved Oxygen A Review

Abstract

Solute entities in solution are assumed to take one of two phases depending on the concentration: one can be seen in the lower concentration range, where each of the solute entities is dispersed in the media of the solution, and the other in the higher range, where the solutes interact with each other. Spectroscopic and thermal investigations and quantum chemical calculations have revealed the presence of a critical concentration which can be taken as the interface of these two phases. An enormously enhanced fluctuation of the refractive index is observed in solutions at the critical concentration. Furthermore, such fluctuations disappear when oxygen is removed from the solution. The values of the critical concentration of the aqueous sodium chloride solutions coincide with the salinities of the seawater and the human blood. These findings are discussed in connection with the laws of thermodynamics.