A new method is proposed for a highly precise thermometry which is used in the reaction calorimetry. The adoption of the thermistor bridge with a constant voltage supply and the improvement of the method for the conversion of unbalanced voltage of bridge into temperature make it possible to determine the temperature with the precision of 2∼5×10-4K.
A new adiabatic calorimeter for heat capacity measurements in the cooling direction has been constructed. In this calorimeter, the heat is removed from the sample quantitatively by means of thermal contact with a cold copper block of known heat capacity. Details of the calorimeter design is described. The results for heat capacity measurements of the empty calorimeter vessel in the cooling direction were compared favorably with those in the heating direction.
The concept of solubility parameter was originally introduced by Hildebrand and Scatchard in solution chemistry. This simple parameter, defined as the square-root of cohesive energy density, is found to be useful for the description of various phenomena reflecting solute-solvent interactions in solution. The role in solution theory and methods of estimation are briefly reviewed. The extension and application of this parameter are discussed with particular attention to the utility for solvent screening in paint technology, polymer solubility and chromatography.