Enthalpies of dilution of l-cystine in aqueous solutions of sodium hydroxide, potassium hydroxide and hydrochloric acid

The enthalpies of dilution of l-cystine in solutions of two strong alkalis and one strong acid have been determined by isothermal flow-mix calorimetry at the temperatures 298.15 K, 303.15 K, 308.15 K, 313.15 K and 318.15 K. Equations of apparent enthalpies of dilution have been obtained from the experimental data in terms of the improved McMillan–Mayer theory. Enthalpic interaction coefficients, h2, h3, and h4, are obtained and the values of pair-wise enthalpic interaction coefficient, h2, discussed in the light of solute–solute and solute–solvent interactions.