化学学报 ›› 2001, Vol. 59 ›› Issue (7): 1089-1095. 上一篇    下一篇

研究论文

氨基苯甲酸异构体在水-乙醇混合溶剂中的离解焓和熵

陈树大;胡新根;潘富敏;林瑞森;方文军   

  1. 浙江嘉兴学院化工系;浙江大学化学系.杭州(310027)
  • 发布日期:2001-07-15

Dissociation enthalpies and entropies of amino benzoic acids in water-ethanol mixtures

Chen Shuda;Hu Xingen;Pan Fumin;Lin Ruisen;Fang Wenjun   

  1. Zhejiang Univ, Dept Chem.Hangzhou(310027)
  • Published:2001-07-15

利用流动混合微量热法测定298.15K时单取代氨基苯甲酸邻,间,对三个异构体在水-乙醇混合溶剂中两个官能团分步离解的离解焓,结合相应的Gibbs自由能数据计算离解熵,从溶剂效应和取代基位置效应探讨其离解热力学行为。

关键词: 氨基苯甲酸, 苯甲酸P, 异构体, 微量热法, 热力学, 离解热, 离解焓, 离解熵

The dissociation enthalpies of 0 - , m -, p - amino benzoic acid in water-ethanol mixtures ranging from pure water up to 0.477 molar fraction of ethano have been determined at 298.15K by the method of mixing-flow microcalorimetry. Combined with the available values of Gibbs free energy reported in the literature, the corresponding values of dissociation entropy were calculated. The enthalpic and entropic effects arising form solvent and substituent are discussed in terms of solute-solvent interaction and tautomeric equilibrium.

Key words: AMINOBENOIC ACID, BENZENECARBOXYLIC ACID P, ISOMER, MICROCALORIMETRIC METHOD, THERMODYNAMICS, HEAT OF DISSOCIATION

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