Thermochemical study of ion-exchange processes: V. Sorption of copper ions in complex-forming resins

The thermodynamic process of copper ion sorption from nitrate solutions has been studied in complex-forming nitrogen and phosphorus resins with the help of a Calvet microcalorimeter. Direct calorimetric measurements were performed at different extents of exchange and the enthalpy variations for the system were obtained. The experimental results show that the van't Hoff equation cannot be used for calculating the enthalpy sorption of transition metal ions in the complex-forming resins.