POTENTIOMETRIC DETERMINATION OF THE DISSOCIATION-CONSTANTS OF SOME MONOCARBOXYLIC ACIDS IN VARIOUS HYDROORGANIC MEDIA

被引：29

作者：

AZAB, HA

AHMED, IT

MAHMOUD, MR

机构：

[1] Chemistry Department, Assiut University, Assiut

来源：

JOURNAL OF CHEMICAL AND ENGINEERING DATA | 1995年 / 40卷 / 02期

关键词：

D O I：

10.1021/je00018a038

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The dissociation constant of acetic acid, benzoic acid, 3-phenylpropenoic acid, 2-methylpropionic acid, and pentanoic acid were determined at 25.0 degrees C (I = 0.1 mol dm(-3) KNO3) by potentiometric pH titration in pure water and water + methanol, water + ethanol, water + dimethylformamide, water + dimethyl sulfoxide, and water + acetonitrile. pK(a) values increase with an increase in the concentration of the organic compounds. These results are discussed in terms of solvent characteristics. Solvent basicity and stabilization of the conjugate acid free base by hydrogen-bonding interactions in hydroorganic solvent media relative to pure aqueous media as well as proton-solvent interaction play an important role in the acid dissociation equilibrium.

引用

页码：523 / 525

页数：3

共 27 条

[1] THERMODYNAMICS OF ELECTROLYTIC DISSOCIATION - FIRST AND 2ND DISSOCIATION-CONSTANTS OF SOME DICARBOXYLIC-ACIDS IN 10-PERCENT (V/V) ACETONE [J].