Thermochemistry of solutions of biochemical model compounds 6. α,ω-dicarboxylic acids, -diamines, and -diols in aqueous solution

Abstract

Enthalpies of solution at infinite dilution in water at 293.15, 298.15, and 303.15 K have been determined for the following compounds of the type X-(CH 2) n -X: n = 2 to 5 for X = OH, n = 2 to 4 for X = NH 2 and n = 2 and 3 for X = COOH. ΔC p.soln ∞ values have been calculated. Using a drop calorimeter, heat capacities for the pure compounds at 298.15 K have been determined. Combining these values with the ΔC p.soln ∞ values, partial molar heat capacities at infinite dilution, C p, 2 ∞, were obtained. C p, 2 ∞ values for 1,6-hexanediol, 1,4-butane- and 1,5-pentane-dicarboxylic acid were determined by measuring the heat capacities of their aqueous solutions at different solute concentrations.