关于苯及其衍生物在盐水溶液中的活度系数的研究

摘录了25℃时苯,甲苯,邻位、间位、对位二甲苯,间位、对位二氯苯及萘在NaF,LiCL,NaBr,NEt~4Br等25种盐的水溶液中的活度系数f,它们的lgf-c~s的关系符合Setchenow盐效应公式。计算了苯及其衍生物在上述25种盐水溶液中的各种盐效应理论的k~s,主要有:1)Debye-macAulay静电理论;2)Conway-Desnoyers-Smith静电理论;3)Masterton-Lee定标粒子理论;4)McDevit-Long内压力理论;5)改进的内压力理论;6)改进的Bockris色散力理论。对各种理论值比较后可以看到改进后的内压力理论k~s值与实验k~s值较为吻合。Bockris色散力理论经改进后计算比较简单,可以判断盐效应符号,盐效应顺序也基本正确。

Study on the activity coefficients of benzene and its derivatives in aqueous salt solutions

We have extracted the activity coefficients, f, of benzene, toluene, o-, m-, and p-xylenes, naphthalene, m-dichlorobenzene and p- dichlorobenzene in 25 aqueous salt solutions at 25℃. (The salts used were NaF, KF, LiCl, KCl, LiBr, KBr, NaNO~3, NaClO~3, NH~4Br, NMe~4Br, NH~4Br, (NH~4)~2SO~4, K~2SO~4, MgCl~2, SrCl~2, BaCl~2, MgSO~4, HCOONa, CH~3COONa, C~2H~5COONa, etc.) The relation between logf and c~s (salt concentration, 0-0.8mol.dm^-^3) was identical with Setchenow's formula. We calculated the theoretical values of benzene and it's derivatives in 25 aqueous salf solutions mentioned above. The were 1)Dybye and MacAulay; 2)Conway et al; 3)McDevit and Long; 4) The scaled partical theory; 5)The internal pressure theory modified by Xie et al; 6)Bockris' dispersion energy theory by Li et al. By comparison we can see the calculated values from the modified is simple when using modified dispersion energy theory, and it can be used to determine the signs of salting-out effect (whether they were negtive or positive).