论文部分内容阅读
本文用紫外分光光度法测定了25℃下萘在LiBr、NaBr,KBr、NH_4Cl、NaF及KF盐水溶液中的活度系数f。将萘的lgf分别对六种盐的浓度c_S作图,得到通过原点的直线,符合Setschenow盐析公式,直线斜率就是盐析常数k。本文还计算了萘在盐水溶液中盐析常数的各种理论值,并对各种理论值进行对比,Debye-MacAulay理论和McDevit-Long公式的计算值都较实验值大2—3倍。Conway等人理论的计算k值对不同盐差别很小,而实验值彼此之间的差别却很大。对体积大的非电解质,色散力对盐析常数的影响不可忽略。本文对Bockris公式进行修正,计算结果表明,它能较正确地指出盐效应的次序及盐析常数的符号。内压力理论改进公式的计算结果不仅能预言盐析常数的符号,也能指出盐析常数大小的顺序,理论值与实经值符合较好。
In this paper, the activity coefficient f of naphthalene in LiBr, NaBr, KBr, NH_4Cl, NaF and KF brine at 25 ℃ was measured by UV spectrophotometry. The lgf of naphthalene were plotted against the concentrations of six salts, c_S, respectively. The straight line passing through the origin was obtained, which was in accordance with the Setchenow salting-out formula. The slope of the straight line was the salting-out constant k. In this paper, various theoretical values of salting-out constant of naphthalene in salt solution are calculated, and various theoretical values are compared. The calculated values of Debye-MacAulay theory and McDevit-Long formula are 2-3 times larger than the experimental values. Conway et al.’s calculation of k values for different salts is very small, and the experimental values differ greatly from one another. For bulky non-electrolyte, the influence of dispersion force on salting-out constant can not be neglected. In this paper, the Bockris formula is revised, and the calculation results show that it can correctly indicate the sequence of salt effect and the sign of salting-out constant. The calculation result of the formula of the internal pressure theory can not only predict the sign of salting-out constant, but also indicate the order of salting-out constants, and the theoretical value is in good agreement with the real value.