Influence of Hydrolysis on the Osmotic Coefficients of the System {yZnCl2 + (1-y)ZnSO4}(aq) at Temperature 298.15 K

Isopiestic vapor pressure measurements were made for {yZnCl(2) + (1 - y)ZnSO4}(aq) solutions with ZnCl2 ionic strength fractions of y = (0.2640, 0.5042, 0.7533, and 1) at the temperature 298.15 K, using KCl(aq) as the reference standard. To investigate the influence of hydrolysis on the osmotic coefficients of {yZnCl(2) + (1 - y)ZnSO4}(aq), the ZnCl2(aq) stock solution was prepared without acidification and supression of hydrolysis. Thus obtained osmotic coefficients of the system {yZnCl(2) + (1 - y)ZnSO4}(aq) at the temperature 298.15 K were compared with the previously published results of the isopiestic measurements for the same system with ZnCl2(aq) stock solution that was acidified to avoid precipitation of zinc hydroxide or a hydrous oxy-chloride or hydroxy-chloride, upon dilution. This way the effects of hydrolysis on the osmotic coefficient values for the system {yZnCl(2) + (1 - y)ZnSO4}(aq) could be compared and analyzed.