DETERMINATION OF THE STANDARD MOLAR ENTHALPY OF FORMATION OF PD3P BY DIRECT-SYNTHESIS DROP CALORIMETRY

We have determined ΔfHδm(Pd3P, cr, 298.15 K) using direct-synthesis drop calorimetry. We measured ΔrHm which is the enthalpy of the reaction: 3Pd(cr) + P(red, am) = Pd3P(cr), at T = (298 ± 1) K. Our result for ΔrHm is -(203 ± 2) kJ·mol-1. Correcting for ΔfHδm(P, red, am, 298.15 K) yields a value for ΔfHδm(Pd3P, cr, 298.15 K) of -(198 ± 3) kJ·mol-1, where the reference state of phosphorus is P(black, orthorhombic). Calculated and experimental powder X-ray diffraction results were compared in order to confirm the identity of the product material as Pd3P. © 1991 Academic Press Limited All rights reserved.