Theoretical Calculation of Activity Coefficients of Liquid Mixtures

[摘要] Significant structure theory was applied to some liquid mixture systems ranging from simple monatomic molecule systems to polyatomic molecule systems, and the activity coefficients ¥ã of the liquid mixture systems were calculated over whole mole fractions using the following thermodynamic relation RTln ¥ãi = (¡ÓAE / ¡ÓNi)T,V,Nj where AE represents the excess Helmholtz free energy, and Ni is the number of molecules of component i. The activity coefficients of the solutions such as monatomic molecule systems (Ar-Kr, Kr-Xe) and diatomic molecule systems (Ar-O2, N2-CO) and CH4-Kr systems whose components have similar shapes for intermolecular potential curves were calculated successfully only with the ¥äEs, correction parameter for energy Es, for mixture systems. For other systems such as Ar-N2, O2-N2 and CH4-C3H8 whose components have dissimilar intermolecular potential curve shapes an additional correction parameters ¥äV and even one more parameter ¥än were necessary [see Eqs.(10)¡­(12)].

[学科分类] 化学（综合）