Effect of NaCl or KCl on the excess enthalpies of alkanol plus water mixtures at various temperatures and salt concentrations

Excess enthalpies of methanol, ethanol, 1-propanol, or 2-propanol + aqueous solution of NaCl or KCI were measured using flow-mix calorimetry at variou s temperatures. Mixtures with all alkanols were investigated at 285.65, 298 .15, 308.15, and 323.15 K; those with ethanol and both propanols were addit ionally investigated at 338.15 K. Furthermore, mixtures with 1-propanol wer e investigated at 353.15 K. The concentration of the salt water component w as varied between 0 and 10 wt % salt in water. Due to the calorimetric flow -mix setup, the total salt concentration in the mixture decreases with incr easing mole fraction of alkanol. The reliability of the experimental setup has already been verified in a previous work (Friese et al., 1998) by compa rison with literature data. The measured excess enthalpies of alkanol (1) (water (2) + salt (3)), h(1+23)(E), are given along with a formula for cal culating the excess enthalpies h(123)(E) occuring when mixing the three com ponents in their reference states, that is pure liquids and infinitely dilu ted salt, respectively.