化学学报 ›› 1958, Vol. 24 ›› Issue (2): 174-186. 上一篇    下一篇

论文

在盐的水溶液中非电解质的活度系数的研究——Ⅱ.脂肪酸盐和季铵盐对于萘在水中溶度的影响

李卓美, 黄子卿   

  1. 北京大学化学系
  • 投稿日期:1958-10-02 发布日期:2013-06-03

STUDIES ON THE ACTIVITY COEFFICIENTS OF NONELECTROLYTES IN AQUEOUS SALT SOLUTIONS——Ⅱ. THE EFFECTS OF SALTS OF FATTY ACIDS AND QUATERNARY AMMONIUM SALTS ON THE SOLUBILITIES OF NAPHTHALENE IN WATER

LI CHOH-MEI, HUANG TZU-CHING, (TZU-CHING HUANG)   

  1. Department of Chemistry, Peking University
  • Received:1958-10-02 Published:2013-06-03

用分光光度计研究一系列的脂肪酸钠盐(甲酸钠至庚酸钠)和一系列的溴化季铵盐(溴化铵,溴化四甲铵,溴化四乙铵和溴化四丁铵)对萘在水中溶度的影响。在脂肪酸钠盐中前四者对萘起盐析作用,而盐析的次序是C1,C2>C3>C4后三者在浓度不太低的情况下起盐溶作用,而盐溶的次序是C5<C6<C7。随着脂肪酸钠盐浓度Cs的增加,log f(f是萘的活度系数)对Cs的图渐渐离开直线而开始下弯。盐的碳原子数愈多,曲线开始下弯的Cs愈小,而下弯的程度亦愈大。溴化铵对萘的作用是盐析,三个季铵盐的作用都是盐溶,盐溶的次序是 (CH3)4NBr<(C2H5)4NBr<(C4H9)4NBr 溴化铵的浓度Cs对log f的图是直线,而三种季铵盐相应的图都不是直线。在季铵盐的浓度接近零时求曲线的斜度即得极限盐溶常数k。作k对季铵盐阳离子半径的图,得到一条直线。如果盐效应表示离子与水分子间静电力和离子与非电解质分子间色散力二者之差,则随着盐的碳原子数的增加,盐析应该逐渐减少,进入盐溶,然后盐溶继续增加。本实验定性证实了这样的看法。

On the assumption that the salt effect (salting-out or salting-in) represents the balance of the electrostatic effect between the ion and the water dipole and the dispersion effect between ion and nonelectrolyte molecule,the solubilities of n-valeric acid in five cobaltammimes were studied and reported in article I of this series[1].