混合电解质溶液的密度和表观摩尔体积的研究

Study on densities and apparent molal volumes of mixed electrolyte aqueous solutions

用高精度密度计测量了２５℃下 ＨＮＯ３－ＵＯ２（ＮＯ３）２， ＫＣＩ－Ｎａ２ＳＯ４和ＮａＣｌ－Ｎａ２ＳＯ４水溶液的密度从而求出了相应的表观摩尔体积；建立了用于混合电解质溶液密度关联的经验方程，用此方程对９个混合电解质水溶液体系的密度进行了关联，精度较高。另外，运用Ｐｉｔｚｅｒ理论，估算了不同温度下 ３９个单一电解质溶液的 Ｐｉｔｚｅｒ体积参数；用引入Ｐｉｔｚｅｒ体积混合参数与离子强度的关系式得到的方程对混合电解质水溶液的表观摩尔体积进行了计算，结果比较满意。

The densities for HNO3-UO2(NO3)2,NaCI-Na2SO. and KCI-Na2SO4 aqueous ablutions were measured with a high precision densimeter at 25℃. The apparent molal volumes were obtained from the measured densities. An empirical equation is introduced to correlate densities for mixed electrolyte aqueous solutions. In addition, Pitzer theory was used to analyze the apparent molal volumes of single and mixed electrolyte aqueous solutions. The new Pitzer equation interaction parameters were evaluated. The working equation which contains the relation between Pitzer mixing parameter () and ionic strength(I), is established to calculate the apparent molal volumes for 9 mixed electrolyte solutions. The results show that the working equation is suitable for these mixed electrolyte aqueous solutions.