Thermochemical properties of electrolyte solutions in 2-alkoxyethanol–water mixtures

Abstract

Dissolution enthalpies for NaCl in mixtures of water with 2-methoxyethanol, 2-ethoxyethanol and 2-butoxyethanol at 298.15 K and for Nal in mixtures of water with 2-butoxyethanol at 298.15 K and 308.15 K have been measured. The standard solution enthalpies Δ_sH° of the salts go through a maximum within the range of high water content. The position and the height of the maximum depend both on the nature of the salt and the size of the 2-alkoxyethanol molecule. It was conclued that 2-alkoxyethanols in water are hydrophobically hydrated and that their hydration shell is weaker than that of alkanols. The mixtures of water with 2-alkoxyethanols, when used as solvents for the electrolytes, exhibit some similarities in thermochemical properties both to water–alkanol mixtures and to mixtures of water with some aprotic solvents.