Thermochemistry of uranium compounds XIV. Standard molar enthalpy of formation at 298.15 K of AgUF6 and its relation to the thermodynamics of fluorination of AgF to AgF2

Abstract The standard molar enthalpy of the reaction: UF 5 (cr, β) + AgF(cr) = AgUF 6 (cr), has been determined by solution calorimetry. From the result for Δ r H m o , −(63.0±1.5) kJ·mol −1 , the standard molar enthalpy of formation of AgUF 6 has been deduced: Δ f H m o (AgUF 6 , cr, 298.15 K) = −(2353.3±8.3) kJ·mol −1 . This value in combination with others leads us to conclude that oxidation reactions of AgF to AgF 2 which are difficult to bring about in practice, are thermodynamically favored.