Enthalpies of dilution of aqueous solutions containing ‘structure-breaking’ solutes and polyols. Biuret–polyol–water and thiourea–polyol–water systems at 298.16 K

Abstract

The enthalpies of dilution in water of aqueous solutions containing a ‘structure-breaking’ solute, thiourea or biuret, and polyols of increasing number of hydroxyl groups, have been measured at 298.16 K, by means of a flow microcalorimeter. The heterotactic coefficients of the virial expansion of the excess enthalpies were determined. The sign and the values of the coefficients are dependent on the polyol and practically independent of the structure-breaking solute. The results are interpreted as due to the prevailing release of water from the destructured domains of the cospheres of polyols.