Interactions in aqueous solutions of urea-like compounds. Heats of mixing of urea, monomethylurea and thiourea at 298.15 K

Abstract

The heats of mixing of aqueous solutions of monomethylurea, urea and thiourea were determined at 298.15 K and the excess enthalpies obtained were expressed in terms of pair- and triplet-interaction coefficients.

The validity of the empirical rule: h_ij²≈h_ij h_jj, relating the self- and cross-interaction coefficients, was tested for the solutes under examination, for which both h_ii, h_jj < 0.