Thermochemistry of nonaqueous solutions of electrolytes: II. Heat of solution of sodium iodide in water-dioxane

The heats of solution of sodium iodide in water and water-dioxane (45. 95, 52. 55, and 68. 15% by wt dioxane at 25° (also for 2° for the first of these mixtures) are reported. The process becomes more exothermic as the dioxane content increases; a qualitative interpretation. The temperature coefficient of the integral heat is zero at 2–25°C for 45. 95 % by wt dioxane. The initial heats of solution of NaI at 25° in water and the mixtures are –1. 81, –4. 99, –5. 39, –6. 63 kcal/mole and bear a linear relation to the composition and dielectric constant of the solvent.