Experimental Determination and Prediction of the Dissociation Energies of AuDy(g) and AgDy(g)

Equilibria involving gaseous species over liquid or solid Au‐Dy and Ag‐Dy mixtures were investigated by high temperature mass spectrometry using Knudsen cells. The enthalpy changes of the reactions could be obtained by applying the third law method. The following dissociation energies were computed (reactions (1)): The standard heats of formation, ΔH0f.298, of AuDy(g) and AgDy(g) have been derived as 402 ± 21 and 448 ± 19 kJ mol−1. The enthalpy changes of the reactions (2) are The experimental values of the dissociation energies of AuDy(g) and AgDy(g) are compared to the values predicted by the Pauling model of a polar bond.