The enthalpies of formation of substitution solid solutions Pr1 + x Ba2 −x Cu3O y

The enthalpies of reactions of substitution solid solutions Pr1 + x Ba2 − xCu3O y , where x = 0, 0.2, 0.4, 0.6, and 0.9, with 1.07 N HCl were measured at 298.15 K in a hermetic swinging isothermic-shell calorimeter. The results and the literature data were used to calculate the standard enthalpies of formation of solid solutions from the elements and oxides. The dependence of the enthalpy of solid solution formation on the degree of praseodymium substitution for barium (x) was revealed.