EXCESS MOLAR VOLUMES OF FORMIC-ACID + WATER, ACETIC-ACID + WATER AND PROPIONIC-ACID + WATER-SYSTEMS AT 288.15-K, 298.15-K AND 308.15-K

Densities and excess molar volumes were determined in the formic acid plus water, acetic acid plus water and propionic acid plus water systems at 288. 15, 298. 15 and 308. 15 K. The results are satisfactorily described using the ideal association model of the type A plus B plus A//2 for the system with formic acid. The Mecke-Kempter model is adequate for the acetic acid plus water and propionic acid plus water systems. In both models the formation of open dimers and open higher associates is postulated for the self-association of carboxylic acids in water.