SOLUTION THERMODYNAMICS OF 1ST-ROW TRANSITION-ELEMENTS .4. APPARENT MOLAL VOLUMES OF AQUEOUS ZNSO4 AND CUSO4 SOLUTIONS FROM 15-DEGREES-C TO55-DEGREES-C

The apparent molal volumes of ZnSO4 and CuSO4 have been determined fro m density data over the temperature range 15 - 55-degrees-C and concen tration range 0 - 1-5 molal. The volume data have been fitted to the P itzer formalism over the entire temperature and concentration range. T he volume changes for the formation of ZnSO4 and CuSO4 ion pairs have been estimated over the temperature range covered and the partial mola l volumes Of ZnSO4 and CuSO4 ion pairs have been derived. The results were used to explain the hydration structure of the ion pair. UV spect ral effects accompanying a change of temperature in the 15 - 65-degree s-C range in CuSO4 solution indicate direct coordination of sulfate an ion to the cupric cation. The process is favored by an increase in tem perature.