The standard enthalpy of formation of the aqueous iodide ion

Abstract

Abstract The enthalpy of reaction of KBrO 3 (c) with HI(aq), and the enthalpies of solution of KBr(c) and I 2 (c) in HI(aq) were measured in an LKB Solution Calorimeter. Combination of the measured values with data from the literature yielded the standard enthalpy of formation of the aqueous iodide ion: ΔH f o (I − , aq, 298.15 K) = −(13.572 ± 0.017) kcal th mol −1 . This result was combined with a literature value for the enthalpy of solution of HI(g) to derive ΔH f o (HI,g) = (6.333 ± 0.026) kcal th mol −1 and was also used to rederive the enthalpy of formation of aqueous XeO 3 , ΔH f (XeO 3 ·96.15H 2 O, 298.15 K) = (98.73 ± 0.22) kcal th mol −1 .