CALORIMETRIC INVESTIGATIONS OF CRYSTALLINE, MOLTEN, AND SUPERCOOLED CA(NO3)2.4H2O AND OF CONCENTRATED CA(NO3)2(AQ)

We have measured heat capacities of Ca(NO3)2·4.02H2O in the crystalline, liquid, and supercooled-liquid states over the temperatures ranges 306.8 K to 318.8 K, 318.8 K to 351.4 K, and 306.8 K to 314.8 K, respectively. We have also measured the melting temperature (316.0 K) and the enthalpy of melting. Further measurements have been made on the heat capacities of concentrated Ca(NO3)2(aq). Results of all of these measurements have been used to calculate the entropy of melting, partial molar heat capacities of Ca(NO3)2and H2O in concentrated Ca(NO3)2(aq), and the glass-transition temperature. © 1993 Academic Press Ltd.