中水活度系數(shù)的計算
(中南工業(yè)大學(xué)化學(xué)系，長沙410083)
摘 要: 將水溶液中電解質(zhì)處理成它們的分子形式而不是它們的離子形式，并基于兩電解質(zhì)之間的相互作用能相對于它們與水的相互作用能可以忽略這一假設(shè)前提，提出了簡化的正規(guī)溶液模型，以計算雙電解質(zhì)溶液體系HCl-H2O-MCln(M=Ni，Cu，Na，F(xiàn)e) 中水的活度系數(shù)。模型中所包含的兩個參數(shù)為組元對的相互作用能，由實(shí)驗(yàn)數(shù)據(jù)估算了所討論體系中涉及的5個組元對的相互作用能。不同雙電解質(zhì)體系得到的HCl-H2O組元對的相互作用能極為吻合，表明所提出的模型是合理的。
關(guān)鍵字: 活度系數(shù) 正規(guī)溶液 電解質(zhì)溶液
（Department of Chemistry, Central South University of Technology,Changsha 410083, P. R. China）
Abstract:In order to calculate the activity coefficients of water in the aqueous solution systems of double electrolytes, HCl and MCln (M=Ni, Cu , Na and Fe ), a simplified regular solution model has been derived based on the assumption that the electrolytes in the aqueous solution can be treated as independent particles instead of their ion forms, and that the interaction of the component pair HCl-MCln in the aqueous solution is very weak as compared with the component pairs HCl-H2O and H2O-MCln. The interchange energies of the component pairs in the discussed systems, ωHCl-H2O, ωH2O-NiCl2, ωH2O-CuCl2, ωH2O-NaCl and ωH2O-FeCl3, have been evaluated from the experimental data to be -69400J·mol-1, -212600J·mol -1, -90550 J·mol-1, -42450 J·mol-1and -198310J·mol-1. The interchange energyωHCl-H2O between HCl and H2O component pair obtained from four different double electrolyte solution systems is almost the same within experimental errors, which indicates that the present model is reasonable to certain extent.
Key words: activity coefficient regular solution electrolyte solution
