Distribution of Benzoic Acid between Benzene and Water and Dimerization of Benzoic Acid in Benzene^1a

Solubility of benzoic acid in acetone, 2-propanol, acetic acid and cyclohexane: Experimental measurement and thermodynamic modeling

“…Thus from the values in Table 4, it indicates that there is no obvious association during the benzoic acid dissolution in acetone, 2-propanol and acetic acid except for cyclohexane, whose value was determined larger than 1. The selfassociation of benzoic acid molecules in hydrocarbon solvent has already been reported by several researchers from the partition coefficient measurements of benzoic acid [21,31].…”

Partition behaviour of benzoic acid in (water+n-dodecane) solutions at T=(293.15 and 298.15)K

“…A detailed description of the measuring procedure has been presented elsewhere [4,10], so only a brief explanation is given here. The experiments were carried out in a magnetically stirred, jacketed equilibrium cell with a working volume of 100 cm 3 and the cell was sealed to prevent the evaporation of solvent.…”

“…As the chemical theory shows, we assumed that there were three kinds of equilibrium for the benzoic acid partitioned in the two immiscible solvents [4,8,12]:…”

“…On the other hand, many reports have shown that the solute molecules may exist in different forms when partitioned in two phases and this kind of isomerization of the solutes still remains a vexing problem in understanding the partition coefficient [2]. For example, the studies on the partition behaviours of organic acid in water and organic solvents [3][4][5][6][7][8] have shown that the organic acids tends to ionize in the aqueous phase but they dimerize in the organic phase when partitioned between aqueous and non-polar organic solvents. Moreover, the dimerization equilibrium constant can be quantitatively estimated from the values of the measured partition coefficients based on the chemical theory [8].…”

“…Different degree dimerizations were observed for different acid-organic solvent systems. Benzoic acid shows moderate degree dimerization in benzene [3,4] while n-butyric acid and n-pentoic acid present very strong dimerization in n-dodecane [6].…”