| Abstract: | An isoperibolic reaction twin calorimeter is described and its application to studying precipitation is shown. This technique is suitable for determining both the total reaction enthalpy and also, in specific ranges of supersaturation, kinetics of the process. The total enthalpy of BaSO4 and CaC2O4 · H2O precipitation at 25 °C was determined as −16.2 and −18.1 kJ mol−1, respectively. The spontneous precipitation of these compounds affected by mixing reactant solutions together proceeds through initial surge of nucleation and fast crystal growth that steeply diminishes. No major wave of secondary nucleation during precipitation was observed. |
