Thermodynamic Characteristics of Silver Perfluorobenzoates C 6 F 5 COOAg·0.5C 6 F 5 COOH and C 6 F 5 COOAg

The thermodynamic characteristics of silver perfluorobenzoates C 6 F 5 COOAg·0.5C 6 F 5 COOH and C 6 F 5 COOAg were studied by thermogravimetry, differential scanning calorimetry, and mass spectrometry. It was found that vaporization of these compounds occurs incongruently to give metallic silver and C 6 F 5 COOH, C 12 F 10 , CO 2 , and C 18 F 14 molecules. Using the 2nd and 3rd laws of thermodynamics, the standard enthalpy of formation of silver perfluorobenzoate was found to be Δ_fH_298^^∘ (C 6 F 5 COOAg, cr) = –1195.6 ± 15.7 kJ/mol and the standard enthalpy of formation of the pentafluorobenzoic acid radical was estimated to be Δ_fH_298.15^^∘ (C 6 F 5 COO • , cr) = –878.6 ± 25.0 kJ/mol.