The low-temperature (5 to 310 K) heat capacity and thermodynamic functions of cesium fluoroxysulfate (CsSO 4F) and the standard potential at 298.15 K for the half-reaction: SO 4F −(aq) + 2H +(aq) + 2e − = HSO 4−(aq) + HF(aq)

Abstract

The low-temperature (5 to 310 K) heat capacity of cesium fluoroxysulfate, CsSO 4F, has been measured by adiabatic calorimetry. At T = 298.15 K, the heat capacity C p o( T) and standard entropy S o( T) are (163.46±0.82) and (201.89±1.01) J · K −1 · mol −1, respectively. Based on an earlier measurement of the standard enthalpy of formation ΔH f o the Gibbs energy of formation ΔG f o(CsSO 4F, c, 298.15 K) is calculated to be −(877.6±1.6) kJ · mol −1. For the half-reaction: SO 4F −(aq)+2H +(aq)+2e − = HSO 4 −(aq)+HF(aq), the standard electrode potential E at 298.15 K, is (2.47±0.01) V.