TRANSITION OF THE MIXING SCHEME IN THE WATER-RICH REGION OF AQUEOUS 2-BUTOXYETHANOL - HEAT-CAPACITIES AND THEIR TEMPERATURE DERIVATIVES

Weak jump anomalies were observed in the temperature derivatives of th e heat capacities of aqueous 2-butoxyethanol. The derivative, (partial -derivative C(p)/partial-derivative T), is proportional to the third d erivative of the Gibbs free energy with respect to T. The loci of thes e anomalies in the composition-temperature field fall on the boundary between two regions previously characterized by differences in the mix ing scheme. Other third derivatives of free energy involving at least one composition differentiation showed peak anomalies at the same boun dary.