Abstract: The dilution enthalpies of serine in aqueous sucrose solutions at 298.15 K were measured by LKB 2277 flow microcalorimetry. Using the McMillan-Mayer theory, the enthalpic pair interaction coefficients (h2) of serine over whole range of aqueous sucrose solutions have been calculated and compared with the enthalpic pair interaction coefficients of serine in aqueous glucose solutions. It is found that h2 of serine in aqueous sucrose and h2 in glucose solutions are negative and become less negative with increasing the concentration of sucrose and glucose. The results are discussed in terms of solute-solute and solute-solvent interactions.

Key words: Serine, Aqueous sucrose solutions, Aqueous glucose solutions, Dilution enthalpy, Structural interactions