The enthalpies of mixing of formamide with myo-inositol and those of their dilution in aqueous sodium chloride solution of different concentration were determined by using flow-mix-isothermal microcalorimetry at 298.15 K. These results were used to determine heterotactic enthalpic interaction coeffi-cients (h_xy, h_xxy and h_xyy) according to the McMillan-Mayer theory. The results show that heterotactic enthalpic pairwise interaction coefficients h_xy were negative in aqueous sodium chloride solution and became less negative with increasing the concentration of sodium chloride.

Key words: formamide, myo-inositol, sodium chloride, heterotactic enthalpic interaction coefficient