Enthalpies of interaction of some alkali-metal halide salts with formamide in water at 25 °C

Abstract

The results are presented of a study of the enthalpies of interaction of formamide with the alkali-metal halides LiCl, NaCl, KCl, CsCl, NaBr, NaI, KF, KBr and KI in water at 25 °C. Data are also given for the enthalpies of dilution of KI solutions at the same temperature. It was found for both cations and anions, as the ionic radius is increased so too does the thermochemical favourability of the formamide–ion interaction. The results are discussed briefly in terms of the competition between the solvation of the solutes and the amide–ion interactions and some comments are made on the role of the ions in protein denaturation.